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Open CASCADE Technology 8.0.0
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Open CASCADE Technology 8.0.0
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This document provides technical details on changes made in particular versions of OCCT. It can help to upgrade user applications based on previous versions of OCCT to newer ones.
SEEK TO THE LAST CHAPTER (UPGRADE TO 8.0.0)
Back-up your code before the upgrade. We strongly recommend using version control system during the upgrade process and saving one or several commits at each step of upgrade, until the overall result is verified. This will facilitate identification and correction of possible problems that can occur at the intermediate steps of upgrade. It is advisable to document each step carefully to be able to repeat it if necessary.
This document describes known issues that have been encountered during porting of OCCT and some applications and approaches that have helped to resolve these issues in known cases. It does not pretend to cover all possible migration issues that can appear in your application. Take this document with discretion; apply your expertise and knowledge of your application to ensure the correct result.
The automatic upgrade tool is provided as is, without warranty of any kind, and we explicitly disclaim any liability for possible errors that may appear due to use of this tool. It is your responsibility to ensure that the changes you made in your code are correct. When you upgrade the code by an automatic script, make sure to carefully review the introduced changes at each step before committing them.
Detailed upgrade notes for OCCT versions 6.5.0 through 7.0.0 are available in the versioned documentation archives, e.g. https://dev.opencascade.org/doc/occt-7.0.0/overview/html/index.html. Refer to the OCCT GitHub releases for per-version change logs.
This section should be considered if application defines custom presentations, i.e. inherited from AIS_InteractiveObject. The previous versions of OCCT have three levels for defining presentation properties (e.g. colors, materials, etc.):
The structure level has de facto not been used for a long time since OCCT presentations always define aspects at the graphic group level (overriding any structure aspects). Within this OCCT release, structure level of aspects has been completely removed. In most cases the application code should just remove missing methods. In those rare cases, when this functionality was intentionally used, the application should explicitly define aspects to the appropriate graphic groups.
Note that defining several different aspects within the same graphic group should also be avoided in the application code since it is a deprecated functionality which can be removed in further releases. Graphic3d_Group::SetGroupPrimitivesAspect() should be the main method defining presentation attributes.
The implementation of Graphic3d_Group::SetGroupPrimitivesAspect() has been changed from copying aspect values to keeping the passed object. Although it was not documented, previously it was possible to modify a single aspect instance, like Graphic3d_AspectFillArea3d and set it to multiple groups. Now such code would produce an unexpected result and therefore should be updated to create the dedicated aspect instance.
The following type definitions in OCCT has been modified to use C++11 types:
For most applications this change should be transparent on the level of source code. Binary compatibility is not maintained, as bool has a different size in comparison with unsigned int.
Fixed-function pipeline has been already deprecated since OCCT 7.0.0. Release 7.1.0 disables this functionality by default in favor of Programmable Pipeline (based on GLSL programs).
Method V3d_View::Export(), based on gl2ps library, requires fixed pipeline and will return error if used with default settings. Applications should explicitly enable fixed pipeline by setting OpenGl_Caps::ffpEnable flag to TRUE within OpenGl_GraphicDriver::ChangeOptions() before creating the viewer to use V3d_View::Export(). This method is declared as deprecated and will be removed in one of the next OCCT releases. The recommended way to generate a vector image of a 3D model or scene is to use an application-level solution independent from OpenGL.
The behavior of transformation persistence flags Graphic3d_TMF_ZoomPers and Graphic3d_TMF_TriedronPers has been changed for consistency with a textured fixed-size 2D text. An object with these flags is considered as defined in pixel units, and the presentation is no more scaled depending on the view height. The applications that need to scale such objects depending on viewport size should update them manually.
Flags Graphic3d_TMF_PanPers and Graphic3d_TMF_FullPers have been removed. Graphic3d_TMF_TriedronPers or Graphic3d_TMF_2d can be used instead depending on the context.
Graphic3d_TransModeFlags is not an integer bitmask anymore - enumeration values should be specified instead. Several transformation persistence methods in PrsMgr_PresentableObject have been marked deprecated. Transformation persistence should be defined using Graphic3d_TransformPers constructor directly and passed by a handle, not value.
Release 7.1.0 introduces Graphic3d_HighlightStyle - an entity that allows flexible customization of highlighting parameters (such as highlighting method, color, and transparency). Therefore, the signatures of the following methods related to highlighting:
Method AIS_InteractiveContext::Hilight is now deprecated and highlights the interactive object with selection style.
A group of methods AIS_InteractiveContext::IsHilighted has changed its behavior - now they only check highlight flags of the object or the owner in the global status. If the highlight color is required on the application level, it is necessary to use overloaded methods AIS_InteractiveContext::HighlightStyle for the owner and the object.
The following methods have been replaced in AIS_InteractiveContext class:
The API of Prs3d_Drawer has been extended to allow setting up styles for both dynamic selection and highlighting. Therefore, it is possible to change the highlight style of a particular object on the application level via SelectMgr_SelectableObject::HilightAttributes() and process it in the entity owner.
Methods TObj_Model::SaveAs and TObj_Model::Load now receive TCollection_ExtendedString filename arguments instead of char*. UTF-16 encoding can be used to pass file names containing Unicode symbols.
The following environment variables have become redundant:
Other environment variables still can be used to customize behavior of relevant algorithms but are not necessary any more (all required resources are embedded).
The following obsolete features have been removed:
The following classes have been changed:
The following obsolete features have been removed:
In classes BRepTools_ReShape and ShapeBuild_ReShape, the possibility to process shapes different only by orientation in different ways has been removed. Thus methods Remove() and Replace() do not have any more the last argument 'oriented'; they work always as if Standard_False was passed before (default behavior). Methods ModeConsiderLo() and Apply() with three arguments have been removed.
Class BRepOffsetAPI_MakeOffsetShape:
The code below shows new calling procedure:
Class BRepOffsetAPI_MakeThickSolid:
The code below shows new calling procedure:
Management of highlight attributes has been revised and might require modifications from application side:
Most AIS_InteractiveContext methods are defined with a flag to update viewer immediately or not. Within previous version of OCCT, this argument had default value TRUE. While immediate viewer updates are useful for beginners (the result is displayed as soon as possible), this approach is inefficient for batch viewer updates, and having default value as TRUE lead to non-intended accidental updates which are difficult to find.
To avoid such issues, the interface has been modified and default value has been removed. Therefore, old application code should be updated to set the flag theToUpdateViewer explicitly to desired value (TRUE to preserve old previous behavior), if it was not already set.
The following AIS_InteractiveContext methods have been changed: Display, Erase, EraseAll, DisplayAll, EraseSelected, DisplaySelected, ClearPrs, Remove, RemoveAll, Hilight, HilightWithColor, Unhilight, Redisplay, RecomputePrsOnly, Update, SetDisplayMode, UnsetDisplayMode, SetColor, UnsetColor, SetWidth, UnsetWidth, SetMaterial, UnsetMaterial, SetTransparency, UnsetTransparency, SetLocalAttributes, UnsetLocalAttributes, SetPolygonOffsets, SetTrihedronSize, SetPlaneSize, SetPlaneSize, SetDeviationCoefficient, SetDeviationAngle, SetAngleAndDeviation, SetHLRDeviationCoefficient, SetHLRDeviationAngle, SetHLRAngleAndDeviation, SetSelectedAspect, MoveTo, Select, ShiftSelect, SetSelected, UpdateSelected, AddOrRemoveSelected, HilightSelected, UnhilightSelected, ClearSelected, ResetOriginalState, SubIntensityOn, SubIntensityOff, FitSelected, EraseGlobal, ClearGlobal, ClearGlobalPrs.
In addition, the API for immediate viewer update has been removed from V3d_View and Graphic3d_StructureManager classes (enumerations Aspect_TypeOfUpdate and V3d_TypeOfUpdate): V3d::SetUpdateMode(), V3d::UpdateMode(), Graphic3d_StructureManager::SetUpdateMode(), Graphic3d_StructureManager::UpdateMode().
The argument theUpdateMode has been removed from methods Graphic3d_CView::Display(), Erase(), Update(). Method Graphic3d_CView::Update() does not redraw the view and does not re-compute structures anymore.
The following Grid management methods within class V3d_Viewer do not implicitly redraw the viewer: ActivateGrid, DeactivateGrid, SetRectangularGridValues, SetCircularGridValues, RectangularGridGraphicValues, CircularGridGraphicValues, SetPrivilegedPlane, DisplayPrivilegedPlane.
The duplicating interface methods accepting Quantity_NameOfColor (in addition to methods accepting Quantity_Color) of TKV3d toolkit have been removed. In most cases this change should be transparent, however applications implementing such interface methods should also remove them (compiler will automatically highlight this issue for methods marked with override keyword).
The capability of reading / writing files in old format using Storage_ShapeSchema functionality from OCCT 6.9.1 has been restored in OCCT 7.2.0.
One can use this functionality in two ways:
The code example below demonstrates how to read shapes from a storage driver using StdStorage class.
The following code demonstrates how to write shapes in OCCT 7.2.0 using StdStorage class.
Previously, BRepLib_MakeFace algorithm changed orientation of the source wire in order to avoid creation of face as a hole (i.e. it is impossible to create the entire face as a hole; the hole can be created in context of another face only). New algorithm does not reverse the wire if it is open. Material of the face for the open wire will be located on the left side from the source wire.
From now on, the offset will always be directed to the outer region in case of positive offset value and to the inner region in case of negative offset value. Inner/Outer region for an open wire is defined by the following rule: when we go along the wire (taking into account edges orientation) the outer region will be on the right side, the inner region will be on the left side. In case of a closed wire, the inner region will always be inside the wire (at that, the edges orientation is not taken into account).
Since 7.2.0 version, method IsPeriodic() returns the corresponding status of periodicity of the basis curve regardless of closure status of the adaptor curve (see method IsClosed()). Method IsClosed() for adaptor can return false even on periodic curve, in the case if its parametric range is not full period, e.g. for adaptor on circle in range [0, \( \pi \)]. In previous versions, IsPeriodic() always returned false if IsClosed() returned false.
The history of the changing of the initial shape was corrected:
Class RWStl now uses class Poly_Triangulation for storing triangular mesh instead of StlMesh data classes; the latter have been removed.
The Error/Warning reporting system of the algorithms in Boolean Component (in all BOPAlgo_* and BRepAlgoAPI_* algorithms) has been refactored. The methods returning the status of errors and warnings of the algorithms (ErrorStatus() and WarningStatus()) have been removed. Instead use methods HasErrors() and HasWarnings() to check for presence of errors and warnings, respectively. The full list of errors and warnings, with associated data such as problematic sub-shapes, can be obtained by method GetReport().
The following public methods in the class ShapeUpgrade_UnifySameDomain became protected:
The following public method has been removed:
The methods BuildPCurveForEdgeOnPlane and BuildPCurveForEdgesOnPlane have been moved from the class BOPTools_AlgoTools2D to the more lower level class BRepLib.
The following obsolete features have been removed:
Multiple changes have been applied to lights management within TKV3d and TKOpenGl:
Graphic3d_AspectFillArea3d has been extended by a new property ShadingModel(), which previously has been defined globally for the entire View.
Previously, a triangle array without normal vertex attributes was implicitly considered as unshaded, but now such array will be shaded using Graphic3d_TOSM_FACET model (e.g. by computing per-triangle normals). Therefore, Graphic3d_TOSM_UNLIT should be explicitly specified to disable shading of triangles array. Alternatively, a material without reflectance properties can be used to disable shading (as before).
The following API changes should be considered while porting custom OpenGl_Element objects:
The public method BuildSection() in the class BOPAlgo_Section has become protected. The methods Perform() or PerformWithFiller() should be called for construction of the result of SECTION operation.
The method BRepAdaptor_CompCurve::SetPeriodic has been eliminated. Since the new version, the method BRepAdaptor_CompCurve::IsPeriodic() will always return FALSE. Earlier, it could return TRUE in case if the wire contained only one edge based on a periodic curve.
Previously, the unclassified faces of BOPAlgo_BuilderSolid algorithm (i.e. the faces not used for solids creation and located outside of all created solids) were used to form an additional (not closed) solid with INTERNAL orientation. Since the new version, these unclassified faces are no longer added into the resulting solids. Instead, the warning with a list of these faces appears.
The following public methods of the BOPAlgo_BuilderSolid class have been removed as redundant:
The API classes in the package BRepAlgo providing access to old Boolean operations are marked as deprecated:
Class CDM_MessageDriver and its descendants have been removed; class Message_Messenger is used instead in all OCAF packages. By default, messenger returned by Message::DefaultMessenger() is used, thus all messages generated by OCAF are directed in the common message queue of OCCT.
In classes implementing OCAF persistence for custom attributes (those inheriting from BinMDF_ADriver, XmlMDF_ADriver), uses of method WriteMessage() should be replaced by call to method Send() of the inherited field myMessageDriver. Note that this method takes additional argument indicating the gravity of the message (Trace, Info, Warning, Alarm, or Fail).
Class Message_PrinterOStream can be used instead of CDM_COutMessageDriver to direct all messages to a stream. If custom driver class is used in the application, that class shall be reimplemented inheriting from Message_Printer instead of CDM_MessageDriver. Method Send() should be redefined instead of method Write() of CDM_MessageDriver. To use the custom printer in OCAF, it can be either added to default messenger or set into the custom Message_Messenger object created in the method MessageDriver() of a class inheriting CDF_Application.
Previously the algorithm could create a shape with the same degenerated edge shared between some faces. Now it is prevented. The algorithm creates the different copy of this edge for each face. The method Generated(...) has been changed in order to apply restriction to the input shape: input shape can be only of type VERTEX, EDGE, FACE or SOLID. For input shape of another type the method always returns empty list.
Previously deprecated Local Context functionality has been removed from AIS package, so that related methods have been removed from AIS_InteractiveContext interface: HasOpenedContext(), HighestIndex(), LocalContext(), LocalSelector(), OpenLocalContext(), CloseLocalContext(), IndexOfCurrentLocal(), CloseAllContexts(), ResetOriginalState(), ClearLocalContext(), UseDisplayedObjects(), NotUseDisplayedObjects(), SetShapeDecomposition(), SetTemporaryAttributes(), ActivateStandardMode(), DeactivateStandardMode(), KeepTemporary(), SubIntensityOn(), SubIntensityOff(), ActivatedStandardModes(), IsInLocal(), AddOrRemoveSelected() taking TopoDS_Shape.
A set of deprecated methods previously related to Local Context and now redirecting to other methods has been preserved to simplify porting; they will be removed in next release.
Now methods GeomConvert::ConcatG1, GeomConvert::ConcatC1, Geom2dConvert::ConcatG1, Geom2dConvert::ConcatC1 modify the input argument representing the flag of closedness.
SelectBasics_PickResult structure has been extended, so that it now defines a 3D point on the detected entity in addition to Depth value along picking ray. SelectMgr_SelectingVolumeManager::Overlap() methods have been corrected to fill in SelectBasics_PickResult structure (depth and 3D point) instead of only depth value, so that custom Select3D_SensitiveEntity implementation should be updated accordingly (including Select3D_SensitiveSet subclasses).
Previously Document format version restored by DocumentRetrievalDriver was propagated using static methods of the corresponding units (like MDataStd or MNaming) to static variables of these units and after that became accessible to Drivers of these units. Now Document format version is available to drivers via RelocationTable. The Relocation table now keeps HeaderData of the document and a format version can be extracted in the following way: theRelocTable.GetHeaderData()->StorageVersion(). Obsolete methods: static void SetDocumentVersion (const Standard_Integer DocVersion) and static Standard_Integer DocumentVersion() have been removed from BinMDataStd, BinMNaming, XmlMDataStd and XmlMNaming.
The entire structure of BRepMesh component has been revised and separated into several logically connected classes.
In new version, deflection is controlled more accurately, this may be necessary to tune parameters of call of the BRepMesh algorithm on the application side to obtain the same quality of presentation and/or performance as before.
BRepMesh_FastDiscret and BRepMesh_FastDiscretFace classes have been removed.
The following changes have been introduced in the API of BRepMesh_IncrementalMesh, component entry point:
Example of usage: Case 1 (explicit parameters):
Some public methods of the class BRepFilletAPI_MakeChamfer are released from excess arguments:
Fill Area, Line and Marker aspects (classes Graphic3d_AspectFillArea3d, Graphic3d_AspectLine3d, Graphic3d_AspectMarker3d and Graphic3d_AspectText3d) have been merged into new class Graphic3d_Aspects providing a single state for rendering primitives of any type. The old per-primitive type aspect classes have been preserved as sub-classes of Graphic3d_Aspects with default values close to the previous behavior. All aspects except Graphic3d_AspectFillArea3d define Graphic3d_TOSM_UNLIT shading model.
The previous approach with dedicated aspects per primitive type was handy in simplified case, but lead to confusion otherwise. In fact, drawing points or lines with lighting applied is a valid use case, but only Graphic3d_AspectFillArea3d previously defined necessary material properties.
As aspects for different primitive types have been merged, Graphic3d_Group does no more provide per-type aspect properties. Existing code relying on old behavior and putting interleaved per-type aspects into single Graphic3d_Group should be updated. For example, the following pseudo-code will not work anymore, because all SetGroupPrimitivesAspect calls will setup the same property:
To solve the problem, the code should be modified to either put primitives into dedicated groups (preferred approach), or using SetPrimitivesAspect in proper order:
Decomposition of Ambient, Diffuse, Specular and Emissive properties has been eliminated within Graphic3d_MaterialAspect definition. As result, the following methods of Graphic3d_MaterialAspect class have been removed: SetReflectionMode(), SetReflectionModeOn(), Ambient(), Diffuse(), Emissive(), Specular(), SetAmbient(), SetDiffuse(), SetSpecular(), SetEmissive().
Previously, computation of final value required the following code:
New code looks like this:
Existing code should be updated to:
Parameters of Text in Graphic3d_Group are moved into a new Graphic3d_Text class. AddText of Graphic3d_Group should be used instead of the previous Text.
The previous code:
should be replaced by the new code:
OpenGl_Text contains Graphic3d_Text field.
OpenGl_TextParam struct is removed. Constructor and Init of OpenGl_Text with OpenGl_TextParam are also removed. Instead of using them, change OpenGl_Text.
Please, note, that after modifying OpenGl_Text, Reset of OpenGl_Text should be called.
FormatParams of OpenGl_Text is replaced by Text.
Historically AIS_InteractiveObject provided two independent mechanisms invalidating presentation (asking presentation manager to recompute specific display mode or all modes):
The latter one has been removed to avoid confusion and unexpected behavior. In addition, two methods AIS_InteractiveObject::Update() have been deprecated in favor of new AIS_InteractiveObject::UpdatePresentations() recomputing only invalidated presentations.
Custom presentations implementing interface methods AIS_InteractiveObject::SetColor() and others should be revised to use AIS_InteractiveObject::SetToUpdate() or updating presentation without recomputation (see AIS_InteractiveObject::SynchronizeAspects() and AIS_InteractiveObject::replaceAspects()).
Proxy classes Prs3d_Presentation, PrsMgr_ModedPresentation and PrsMgr_Prs have been removed. Code iterating through the list of low-level structures AIS_InteractiveObject::Presentations() should be updated to access PrsMgr_Presentation directly. Forward declarations of Prs3d_Presentation should be corrected, since it is now a typedef to Graphic3d_Structure.
Proxy classes SelectBasics_SensitiveEntity and SelectBasics_EntityOwner have been removed - Select3D_SensitiveEntity and SelectMgr_EntityOwner should be now used directly instead.
Graphic3d_PolygonOffset default constructor has been corrected to define Units=1 instead of Units=0. Default polygon offset settings Mode=Aspect_POM_Fill + Factor=1 + Units=1 are intended to push triangulation (Shaded presentation) a little bit behind of lines (Wireframe and Face Edges) for reducing z-fighting effect of Shaded+Wireframe combination. The change in defaults (Units changed from 0 to 1) is intended to cover scenario when camera direction is perpendicular to model plane (like 2D view).
Application observing unexpected visual difference on this change should consider customizing this property within AIS_InteractiveContext default attributes or on per-presentation basis via Graphic3d_Aspects::SetPolygonOffset() methods.
Interface of insertion ZLayer in the viewer has been improved with ability to insert new layer before or after existing one. Previously undocumented behavior of V3d_Viewer::AddZlayer() method has been corrected to insert new layer before Graphic3d_ZLayerId_Top. Applications might need revising their custom layers creation code and specify precisely their order with new methods V3d_Viewer::InsertLayerBefore() and V3d_Viewer::InsertLayerAfter().
Applications using integer values of the following enumerations in persistence should be corrected as these enumerations have been modified:
| Name |
|---|
| AIS_TypeOfAttribute |
| Aspect_InteriorStyle |
| Font_FontAspect |
env.bat produced by Visual Studio project generator genproj.bat has been modified so that CSF_DEFINES% variable is reset to initial state. Custom building environment relying on old behavior and setting extra macros within CSF_DEFINES% before env.bat should be updated to either modify custom.bat or setup new variable CSF_DEFINES_EXTRA% instead.
Since OCCT 7.4.0 Boolean Operations algorithm uses BVH tree instead of UBTree to find the pairs of entities with interfering bounding boxes. The following API changes have been made:
Standard_Stream.hxx header, commonly included by other OCCT header files, does no more add entities from std namespace related to streams (like std::cout, std::istream and others) into global namespace. The application code relying on this matter should be updated to either specify std namespace explicitly (like std::cout) or add "using std::" statements locally.
OCCT 3D Viewer has been improved to properly perform lighting using in linear RGB color space and then convert result into non-linear gamma-shifted sRGB color space before displaying on display. This change affects texture mapping, material definition and color definition.
Previously Quantity_Color definition was provided with unspecified RGB color space. In practice, mixed color spaces have been actually used, with non-linear sRGB prevailing in general. Since OCCT 7.5.0, Quantity_Color now specifies that components are defined in linear RGB color space.
This change affects following parts:
Unexpected const-ness of Aspect_Window::DoResize() method has been removed, so that application classes implementing this interface should be updated accordingly.
Enumeration BRepOffset_Type is renamed to ChFiDS_TypeOfConcavity.
Now by default offset faces of non-planar faces may be planar faces if their originals can be approximated by planes.
The following changes could be highlighted while porting:
Properties Prs3d_Drawer::HLRAngle() and Prs3d_Drawer::HLRDeviationCoefficient() have been removed from classes Prs3d_Drawer, AIS_Shape and AIS_InteractiveContext. Prs3d_Drawer::DeviationAngle() should be now used instead of Prs3d_Drawer::HLRAngle() and Prs3d_Drawer::DeviationCoefficient() instead of Prs3d_Drawer::HLRDeviationCoefficient(). The default value of Prs3d_Drawer::DeviationAngle() property has been changed from 12 to 20 degrees to match removed Prs3d_Drawer::HLRAngle(), previously used as input for triangulation algorithm.
Methods computing HLR presentation within PrsMgr_PresentableObject::Compute() have been renamed to PrsMgr_PresentableObject::computeHLR() and now accept Graphic3d_Camera object instead of removed Prs3d_Projector.
Presentation classes displaying Dimensions and Relations have been moved from AIS package to PrsDim. Corresponding classes should be renamed in application code (like AIS_LengthDimension -> PrsDim_LengthDimension).
The method Select3D_SensitiveEntity::NbSubElements() has been changed to be constant. Select3D_SensitiveEntity subclasses at application level should be updated accordingly.
Offset direction, which used in class Adaptor2d_OffsetCurve for evaluating values and derivatives of offset curve is unified for offset direction used in class Geom2d_OffsetCurve: now offset direction points to outer ("right") side of base curve instead of the previously used inner ("left") side. Old usage of class in any application should be changed something like that:
Adaptor2d_OffsetCurve aOC(BaseCurve, Offset) --> Adaptor2d_OffsetCurve aOC(BaseCurve, -Offset)
The progress indication mechanism has been revised to eliminate its weak points in previous design (leading to implementation mistakes). Redesign also allows using progress indicator in multi-threaded algorithms in more straight-forward way with minimal overhead. Note however, that multi-threaded algorithm should pre-allocate per-task progress ranges in advance to ensure thread-safety - see examples in documentation of class Message_ProgressScope for details.
Classes Message_ProgressSentry and Message_ProgressScale have been removed. New classes Message_ProgressScope and Message_ProgressRange should be used as main API classes to organize progress indication in the algorithms. Instances of the class Message_ProgressRange are used to pass the progress capability to nested levels of the algorithm, and an instance of the class Message_ProgressScope is to be created (preferably as local variable) to manage progress at each level of the algorithm. The instance of Message_ProgressIndicator is not passed anymore to sub-algorithms. See documentation of the class Message_ProgressScope for more details and examples.
Methods to deal with progress scopes and to advance progress are removed from class Message_ProgressIndicator; now it only provides interface to the application-level progress indicator. Virtual method Message_ProgressIndicator::Show() has changed its signature and should be updated accordingly in descendants of Message_ProgressIndicator. The scope passed as argument to this method can be used to obtain information on context of the current process (instead of calling method GetScope() in previous implementation). Methods Show(), UserBreak(), and Reset() are made protected in class Message_ProgressIndicator; methods More() or UserBreak() of classes Message_ProgressScope or Message_ProgressRange should be used to know if the cancel event has come. See documentation of the class Message_ProgressIndicator for more details and implementation of Draw_ProgressIndicator for an example.
Let's take a look onto typical algorithm using an old API:
The following guidance can be used to update such code:
const Handle(Message_ProgressIndicator)& with const Message_ProgressRange& in arguments of the methods that support progress indication. Message_ProgressIndicator object should be now created only at place where application starts algorithms.Message_ProgressSentry with Message_ProgressScope. Take note that Message_ProgressScope has less arguments (no "minimal value"). In other aspects, Message_ProgressScope mimics an iterator-style interface (with methods More() and Next()) close to the old Message_ProgressSentry (pay attention to extra functionality of Message_ProgressScope::Next() method below). Note that method Message_ProgressScope::Close() is equivalent of the method Relieve() of Message_ProgressSentry in previous version. Class Message_ProgressSentry is still defined (marked as deprecated) providing API more close to old one, and can be still used to reduce porting efforts.Take a look onto ported code and compare with code above to see differences:
Operators << with left argument Handle(Message_Messenger), used to output messages with a stream-like interface, have been removed. This functionality is provided now by separate class Message_Messenger::StreamBuffer. That class contains a stringstream buffer which can be filled using standard stream operators. The string is sent to a messenger on destruction of the buffer object, call of its method Flush(), or using operator << with one of ostream manipulators (std::endl, std::flush, std::ends). Manipulator Message_EndLine has been removed, std::endl should be used instead.
New methods SendFail(), SendAlarm(), SendWarning(), SendInfo(), and SendTrace() are provided in both Message_Messenger class and as static functions in Message package (short-cuts to default messenger), returning buffer object for the output of corresponding type of the message.
The code that used operator << for messenger, should be ported as follows.
Before the change:
After the change, single-line variant:
After the change, extended variant:
Previously, sub-classes of Message_Printer have to provide a triplet of Message_Printer::Send() methods accepting different string representations: TCollection_AsciiString, TCollection_ExtendedString and Standard_CString. Message_Printer interface has been changed, so that sub-classes now have to implement only single method Message_Printer::send() accepting TCollection_AsciiString argument and having no Endl flag, which has been removed. Old three Message_Printer::Send() methods remain defined virtual with unused last argument and redirecting to new send() method by default.
Redundant class Prs3d_Root has been marked as deprecated - Prs3d_Presentation::NewGroup() should be called directly.
Class CDF_Session has been removed. That class was used to store global instance of OCAF application (object of class CDM_Application or descendant, typically TDocStd_Application). Global directory of all opened OCAF documents has been removed as well; such directory is maintained now by each instance of the CDM_Application class.
This allows creating programs that work with different OCAF documents concurrently in parallel threads, provided that each thread deals with its own instance of TDocStd_Application and documents managed by this instance.
Note that neither TDocStd_Application nor TDocStd_Document is protected from concurrent access from several threads. Such protection, if necessary, shall be implemented on the application level. For an example, access to labels and attributes could be protected by mutex if there is a probability that different threads access the same labels / attributes:
Draw Harness hotkeys W (Wireframe) and S (Shaded) have been re-mapped to Ctrl+W and Ctrl+S. Hotkey A has been remapped to Backspace. Hotkeys WASD and Arrays are now mapped for walk-through navigation in 3D Viewer.
Message files (with extension .msg) are now expected to be in UTF-8 encoding (unless they have UTF-16 BOM in which case UTF-16 is expected). This allows using arbitrary Unicode symbols for localization of messages.
Existing message files containing 8-bit characters (previously interpreted as characters from Latin-1 code block) should be converted to UTF-8.
Interfaces Adaptor2d_Curve2d, Adaptor3d_Curve and Adaptor3d_Surface now inherit Standard_Transient and can be Handle-managed. No more necessary parallel hiererchy of classes Adaptor2d_HCurve2d, Adaptor3d_HCurve and Adaptor3d_HSurface (generated from generic templates by WOK) has been eliminated. Existing code using old Handle classes should be updated to:
Behavior of the method TCollection_ExtendedString::Print(Standard_OStream&) and corresponding operator << has changed. Previously it printed all Latin-1 symbols (those in range 0x80-0xff) as '\0' (effectively losing them); symbols above 0xff were converted to hex representation (formatted like XML Numeric Character Reference). Now all symbols are sent to stream as UTF-8 byte sequences. Existing code relying on old behavior, if any, shall be rewritten.
Geom_RectangularTrimmedSurface sequentially trimming in U and V directions already no longer loses the first trim. For example:
gives different result. In current version ST1 - surface trimmed only along V, U trim is removed; After modification ST1 - surface trimmed along U and V, U trim is kept.
The methods XmlLDrivers::StorageVersion() and BinLDrivers::StorageVersion() were removed. Since now TDocStd_Document manipulates the storage format version of a document for both XML and binary file formats. For this the methods StorageFormatVersion() and ChangeStorageFormatVersion() were moved from CDM_Document to TDocStd_Document. The methods are used to get and set the storage format version of a document. A new enumeration TDocStd_FormatVersion lists the storage format versions of a document. By default, the document uses the latest (current) storage format version. In order to save a document in an older storage format version, call the method ChangeStorageFormatVersion() with one of the values from the enumeration. This value will be used by storage drivers of a corresponding OCAF file format (XML or binary) and the document will be saved following the rules of the specified storage format version (corresponding to an older version of Open CASCADE Technology). This way an application based on an old version of Open CASCADE Technology may read documents saved by new applications (based on newer version of Open CASCADE Technology).
A new OCAF document may be created only by means of the method NewDocument() from CDF_Application (redefined in TDocStd_Application). The methods CreateDocument() are deleted in all retrieval drivers.
Information about per-vertex triangulations normals is now stored in BinOCAF and XmlOCAF document, BRep and Binary BRep Shape formats (only in case of triangulation-only Faces, with no analytical geometry to restore normals).
Versions of formats have been changed (11 for BinOCAF, 10 for XmlOCAF, 4 for BRep Shape and 3 for Binary BRep Shape). Files written with the new version will not be readable by applications of old versions.
All kinds of binary document formats since the new version 12 saved with support of partial reading (sub-set of labels and sub-set of attributes). For that the shapes data structures are stored with the related NamedShape attributes in the file, not in the particular section in the start of the document. Also, size allocated for each label is stored in the file. This allows to skip big parts of document in partial reading mode if needed.
As a result, the new binary files become some smaller, but default reading and writing of documents may take some more time (depenging on the environment), up to 15 percents slower in the worse cases. Backward compatibility (loading of old documents in the newer version) is still fully supported, as well as writing the older versions of the document.
Poly_Triangulation does no more provide access to internal array structures: methods Nodes(), ChangeNode(), Triangles(), ChangeTriangle(), UVNodes(), ChangeUVNode(), Normals() have been removed. Methods of Poly_Triangulation for accessing individual nodal properties / triangles by index and implementing copy semantics should be used instead. The same is applicable to Poly_PolygonOnTriangulation interface.
Accessors to standard materials have been modified within Declarations.glsl (occFrontMaterial_Diffuse() -> occMaterial_Diffuse(bool) and similar). Applications defining custom GLSL programs should take into account syntax changes.
Nodal color vertex attribute is now modulated in the same way as a color texture - color is multiplied by material coefficients (diffuse/ambient/specular in case of a common material definition). Existing code defining nodal colors should be updated to:
OCCT now provides two separate toolkits - TKOpenGl depending on desktop OpenGL and TKOpenGles depending on OpenGL ES. Both libraries can be now built simultaneously on systems providing both APIs (like desktop Linux).
Existing applications depending on OpenGL ES (mobile projects first of all) should be adjusted to link against TKOpenGles. Note that both TKOpenGl and TKOpenGles keep exporting classes with the same name, so applications should not attempt to link both libraries simultaneously.
Access to an OCAF label via its entry is accelerated. In order to activate it, call TDF_Data::SetAccessByEntries(). The method TDF_Tool::Label(), which returns a label by an entry, becomes faster for about 10 .. 20 times. It has sense for applications, which use an entry as a unique key to access the data in OCAF tree. Also, the method TDF_Tool::Entry(), which returns an entry for a label, is accelerated as well.
Method SetProgressIndicator() has been removed due to Progress indicator mechanism refactoring. To enable progress indicator and user break in Boolean operations user has to pass progress range as a parameter to Perform or Build method. For example:
Now the classes accept adaptors instead objects as input parameters. BRepLib_CheckCurveOnSurface does no more provide access to curves, surface and parameters: methods PCurve(), PCurve2(), Surface() and Range() have been removed. BRepLib_CheckCurveOnSurface: the default value of the isMultiThread parameter of the Perform() function has been changed from true to false GeomLib_CheckCurveOnSurface does no more provide access to curve, surface and parameters: methods Curve(), Surface() and Range() have been removed. GeomLib_CheckCurveOnSurface: the default value of the isMultiThread parameter of the Perform() function has been changed from true to false
The following functions in GeomLib_CheckCurveOnSurface have been modified:
Building OCCT now requires C++17-compliant compiler (see Building OCCT for details). It is recommended using Visual Studio 2019 or later (2022 preferred) for building OCCT on Windows platform.
theIsParallel parameter has been removed from Put/Compute/Perform from the next classes:
Now, to set this flag, it is necessary to use method SetParallel() For example:
Prs3d_Drawer getters no more implicitly create "default" aspects. If specific property has not been set before to this drawer instance nor to linked drawer instance, then nullptr property will be returned. Make sure to set property beforehand or to call SetOwn* / SetupOwn* methods to derive from defaults.
Applications extending OCCT 3D Viewer and calling OpenGL functions directly (like ::glEnable(), e.g. using global namespace) might be affected by changes in OpenGl_GlFunctions.hxx. This header, as well as OpenGl_GlCore20.hxx and similar, no more include system OpenGL / OpenGL ES headers to define function table. Application code calling OpenGL functions directly should be changed to either use OpenGl_Context::core11fwd (as designed) or to include system OpenGL headers in advance (with help of OpenGl_GlNative.hxx).
Method StdPrs_ToolTriangulatedShape::Normal() has been removed. Please use BRepLib_ToolTriangulatedShape::ComputeNormals() to fill in normal attributes in triangulation and fetch them directly using Poly_Triangulation::Normal().
A new way of using the BRepExtrema_ShapeProximity class was provided for computing a proximity value between two shapes. If at initialization of the BRepExtrema_ShapeProximity class the theTolerance parameter is not defined (Precision::Infinite() by default), the proximity value will be computed.
The NCollection containers have been modernized to work with move semantics through the new Move operator and Move constructor. It is recommended to leverage this functionality in the development process.
Backward compatibility with STL allocators has been implemented to use the OCCT memory manager with STL allocators (NCollection_Allocator, NCollection_OccAllocator).
Additionally, utilities have been introduced to work with shared_ptr and unique_ptr using the OCCT memory manager (Standard_MemoryUtils.hxx).
NCollection container's Clear(const bool theReleaseMemory = true) have been changed to Clear(const bool theReleaseMemory = false).
Impacted classes include IndexedMap, IndexedDataMap, Map, DataMap, DynamicArray(Vector), IncAllocator.
This means that allocated memory for the container will be reused. In this case, it's necessary to be careful with IncAllocator::Reset() to control owners of memory blocks.
The HashCode(value, upperBound) static method has been removed and IsEqual(value1, value2) is no longer used in the map.
NCollection's map now operates on an STL-like hash mechanism: a struct with a public operator size_t operator()(object&) const and bool operator(object&, object&) const.
The difference between STL and OCCT is that the hash struct and comparator are combined into a single struct to reduce conflicts on OCCT's user side.
Hash utils have been implemented to hash objects, returning uint32_t and uint64_t depending on the template (Standard_HashUtils.hxx). Algorithms used are MurmurHash and FNVHash.
Benefits:
unordered_map and unordered_set.The migration problem will occur at compile time. Make sure that int HashCode has been changed anywhere to size operator and bool IsEqual to bool operator.
The majority of include files containing only specialized hashes have been removed. Their functionality has been consolidated into the hashed object include file (in the "std" namespace).
It is guaranteed that each removed hash class has been transferred to the native hash mechanism of the hashed class.
The migration problem may arise at compile time. Ensure that you remove any files that have been deprecated.
DE TK components have been combined or separated based on specific CAD formats to support plug-in ability.
TKDESTEP, TKDEOBJ, TKDEIGES, TKDEGLTF, TKDEVRML, TKDEPLY, TKDESTL.TKXSDRAWSTEP, TKXSDRAWOBJ, TKXSDRAWIGES, TKXSDRAWGLTF, TKXSDRAWVRML, TKXSDRAWPLY, TKXSDRAWSTL.Migration problems may occur during configuration time or compile time. Ensure that you update your project configuration accordingly.
The STEP interface now uses Static_Interface to extract exchange settings.
A new ability has been implemented to determine parameters in STEP, avoiding Static_Interface.
ReadFile or Perform.Transfer or Perform.Standard.hxx has a new method AllocateOptimal for allocating without post-processing (cleaning).
New profiles to allocate memory (defined at configuration time):
Native - allocates with standard malloc and calloc functionality, performance depends on the OS.TBB - allocates with TBB's scalable allocator functionality.JeMalloc - allocates with jemalloc functions.Flexible - old-way allocation which defines allocation method in real-time by environment variables.The most recommended manager is JeMalloc. To use it with a plugin system, like DRAW, please ensure that JeMalloc was built with the --disable-initial-exec-tls flag. For more details, visit JeMalloc.
BUILD_OPT_PROFILE is a new variable to define optimization level. Available profiles:
Default - specializes only in quality-dependent parameters for the compiler.Production - specializes in performance and quality-dependent parameters for the compiler and linker.The entire code base has been formatted with clang-format 18.1.8 (Windows) using settings available in the root of the repository. Most custom patches on top of previous releases will likely have merge conflicts. When encountering merge conflicts, it is recommended to use clang-format to format the code. To maintain patches, it is recommended to merge them into the main repository as part of a contribution. See Get Involved and Contribution Guide.
The OCCT repository has been migrated to GitHub. The new repository is available at GitHub. The old repository will be available for some time, but it is recommended to use the new repository for all new changes. Contribution to the new repository is available through the GitHub interface - see Get Involved and Contribution Guide.
The GenProj tool is no longer supported. It is recommended to use CMake for building OCCT. In case of problems, please refer to the CMake Guide.
The exception for transformation with scale has been disabled by default. These exceptions were enabled in OCCT 7.6.0 for all cases of applying a transformation on a TopoDS_Shape with scale or negative determinant. Now the exceptions are disabled by default but can be enabled by changing the parameter in the method which applies the transformation on TopoDS_Shape.
The DE Wrapper classes have been reorganized to follow a single style throughout the OCCT open source and commercial code. All DE formats starting from 7.8.0 were grouped into their own TKs with the TKDE prefix. Now all DE Wrapper interfaces have moved to their own package with the DE prefix. DE Wrapper classes follow the pattern: DE<Format>_Parameters, DE<Format>_Provider, and DE<Format>_ConfigurationNode. Example: DESTEP_Parameters, DESTEP_Provider, DESTEP_ConfigurationNode.
The shape healing parameters have migrated from the resource file to the DE interface. The previous implementation was based on the resource file or Interface_Static. Now the parameters are stored in the DE_ShapeFixParameters structure with the option to use a string-string map to store extra parameters. To use the previous interface, use code similar to:
It is recommended to use the new interface to store parameters in the DE_ShapeFixParameters structure directly.
During transfer operations, all parameters that were stored in Interface_Static have moved to their own DE structure. The parameters are read only once during initialization and stored in the model. Parameters are now available as part of the DE Wrapper interface, for example: DESTEP_Parameters, DEIGES_Parameters. Code samples showing how to set the parameters can be found in DESTEP_Provider and DEIGES_Provider.
The Handle_* type names have been deprecated in favor of directly using the macro. The Handle_* type names are still available, but it is recommended to use the macro directly. Example:
The NCollection_Map class has been reorganized to migrate extra methods to the NCollection_MapAlgo class. Boolean operations on maps are now available in the NCollection_MapAlgo class.
OCCT 8.0.0 is a major release with broad, source-incompatible changes across the foundation, modeling-data, and modeling-algorithm layers. The bulk of the per-line changes (handle macro, Standard_* typedefs, Standard_OVERRIDE etc., TColStd_*/TopTools_* typedefs, DEFINE_HARRAY*, Standard_Failure::Raise) can be migrated automatically. A smaller set of changes — exception handling, removed/renamed APIs, reworked evaluation hierarchies, and packages that have been removed outright — require manual review.
OCCT 8.0.0 raises the supported toolchain baseline and reorganizes the source tree.
CXX_STANDARD must be raised to 17 or higher. Compiler minimums: VS 2019 (2022 preferred), GCC 8.0, Clang 7.0, Apple Clang 11.0, MinGW-w64 7.3.BUILD_USE_PCH=ON for precompiled headers).src/<Package>/ layout to src/<Module>/<Toolkit>/<Package>/. Build scripts that hard-coded the old layout, copied OCCT into a vendored tree, or referenced specific source paths must be updated.share/<OCCT_PROJECT_NAME>/resources/ (vcpkg-compliant layout). The CSF_* environment variables (CSF_OCCTResourcePath, CSF_IGESDefaults, CSF_STEPDefaults, CSF_PluginDefaults, CSF_XCAFDefaults, etc.) are the supported way to point OCCT at the resources at runtime; CASROOT remains supported for compatibility.BUILD_PATCH CMake option is removed**. There is no replacement; apply patches at the source level or via your build system.OCCT_PROJECT_NAME** is a new CMake cache variable that controls the install layout's project name (defaults to opencascade); it is the supported customization hook for vcpkg and embedded builds.-symbolic Unix linker flag is no longer applied. RTTI behavior with dlopen-style plugins should be re-validated.A 12-phase Python migration suite is shipped with OCCT under adm/scripts/migration_800/. It requires Python 3.6+ with no external dependencies. Each phase supports --dry-run to preview changes.
For external projects, the recommended entry point is the wrapper script:
The phases run in order and cover, in summary:
migrate_handles.py- Handle(T) to occ::handle<T>, Handle(T)::DownCast() to occ::down_cast<T>().migrate_standard_types.py- Standard_Boolean/Integer/Real/... to bool/int/double/..., Standard_True/False to true/false.migrate_macros.py- Standard_OVERRIDE to override, Standard_NODISCARD to [[nodiscard]], Standard_FALLTHROUGH to [[fallthrough]];, etc.cleanup_define_handle.py- removes redundant DEFINE_STANDARD_HANDLE macros.cleanup_deprecated_typedefs.py- removes deprecated typedef/using declarations and replaces usages.collect_typedefs.py- collects NCollection typedef mappings (analysis phase).replace_typedefs.py- replaces TColStd_*/TopTools_* etc. with NCollection_*<T>.remove_typedef_headers.py- removes typedef-only headers and updates FILES.cmake.cleanup_forwarding_headers.py- cleans up forwarding/include-only headers.cleanup_unused_typedefs.py- removes unused typedef declarations.cleanup_access_specifiers.py- removes redundant access specifiers.migrate_raise_to_throw.py- converts Standard_Failure::Raise(...) to throw Standard_Failure(...).The accompanying migrate_hcollections.py script converts DEFINE_HARRAY1/DEFINE_HARRAY2/DEFINE_HSEQUENCE macros to the NCollection_HArray1/HArray2/HSequence template classes.
After all phases, verify_migration.py reports any remaining legacy patterns:
Pre-generated mapping files (collected_typedefs.json, collected_deprecated_typedefs.json) are bundled in adm/scripts/migration_800/; external projects do not need to re-scan the OCCT source. The migration scripts also support .h/.c/.hpp/.cpp files and can automatically add or replace #include directives when replacing typedefs.
Standard_UNUSED is an exception and requires manual migration to [[maybe_unused]] due to stricter placement rules of the C++ attribute.
The Handle() macro and ::DownCast are replaced with explicit occ::handle<> / occ::down_cast<> templates:
OCCT's primitive typedefs are migrated to standard C++ types:
| Deprecated typedef | Replacement |
|---|---|
Standard_Boolean | bool |
Standard_True/False | true/false |
Standard_Integer | int |
Standard_Real | double |
Standard_ShortReal | float |
Standard_Byte | uint8_t |
Standard_Size | size_t |
Standard_Address | void* |
Standard_CString | const char* |
Standard_Character | char |
Standard_ExtCharacter | char16_t |
Standard_Time | std::time_t |
The Standard_* typedefs are still defined for source-level compatibility, but their use is discouraged in new code and the migration scripts rewrite them to the native C++ types.
Legacy attribute macros are replaced with the standard C++ attributes and keywords:
| Deprecated macro | Replacement |
|---|---|
Standard_OVERRIDE | override |
Standard_NODISCARD | [[nodiscard]] |
Standard_FALLTHROUGH | [[fallthrough]]; |
Standard_Noexcept | noexcept |
Standard_DELETE | = delete |
Standard_THREADLOCAL | thread_local |
Standard_ATOMIC(T) | std::atomic<T> |
Standard_Failure now inherits from std::exception. OCCT exceptions can be caught by standard catch (const std::exception&) blocks, the message is exposed through what(), and ExceptionType() returns the exception class name.
Static Raise(), Instance(), and Throw() methods on Standard_Failure and its subclasses are removed. Use the C++ throw statement directly:
GetMessageString() is deprecated- use what(). The error-handler stack used by OCC_CATCH_SIGNALS is now thread_local instead of being protected by a global mutex; threads no longer contend on error-handler state. Catches() and LastCaughtError() static methods on Standard_ErrorHandler have been removed; OCC_CATCH_SIGNALS exposes a new Raise() re-throw method.
If you previously combined OCCT exceptions with custom catch logic that relied on Catches() / LastCaughtError(), restructure the handler around the standard try/catch flow.
Seek() and ChangeSeek() are removed from NCollection_Map. Use the unified Contained() API, which returns std::optional<std::reference_wrapper<T>>:
The non-throwing TryEmplace/TryBind methods are now available on all map types and avoid the throwing two-step "find then add" pattern:
C++17 structured bindings are supported via Items() / IndexedItems() views:
New collection types are available in 8.0.0 and may be preferred over their predecessors in new code:
NCollection_FlatMap / NCollection_FlatDataMap- cache-friendly open-addressing hash containers with Robin Hood hashing.NCollection_OrderedMap / NCollection_OrderedDataMap- insertion-order-preserving maps with O(1) lookup, append, and removal.NCollection_KDTree- header-only static balanced KD-Tree for spatial queries (gp_Pnt, gp_Pnt2d, gp_XYZ, gp_XY).NCollection_ForwardRange- lightweight forward-range adapter for non-owning index spans.Standard_Mutex is deprecated in favor of std::mutex.
The package-specific collection typedefs (TColStd_*, TopTools_*, TColgp_*, etc.) are kept as deprecated aliases of the underlying NCollection_*<T> template instantiations and emit deprecation warnings on use. The migration scripts rewrite call sites to use the templates directly:
Two package typedef wrappers have been removed entirely (no backward-compatible aliases): TColGeom and TColGeom2d. Replace with NCollection_Array1<occ::handle<Geom_Curve>> and the equivalent Geom2d_* form:
BSpline and Bezier curves and surfaces store poles, weights, and knots as direct array value-members rather than NCollection_HArray* handles. The previously nullable Weights() accessor is replaced by WeightsArray(), which always returns a valid reference- non-rational geometry exposes a non-owning view over a static unit-weights buffer with zero allocation:
Copy-out accessor overloads (those taking an output NCollection_Array1 to fill) are deprecated in favour of zero-copy const-reference returning versions:
The same deprecation applies to single-element accessors throughout the Convert package- prefer the batch const-reference accessors (Poles(), Weights(), Knots(), Multiplicities()).
The geometry evaluation dispatch hierarchy has been redesigned across all 32 Geom/Geom2d curve and surface classes and across Adaptor3d_Curve, Adaptor3d_Surface, and their subclasses.
The new primary virtual dispatch points are EvalD0, EvalD1, EvalD2, EvalD3, and EvalDN. They return POD result structs (Geom_CurveD1 / D2 / D3, Geom_SurfD1 / D2 / D3, and the Geom2d_* equivalents) and use exception-based error handling on the hot path.
The old Value() and D0 / D1 / D2 / D3 / DN methods are kept as non-virtual inline backward-compatible wrappers that delegate to EvalD*. If your code overrides D0/D1/D2/D3/DN on a Geom* class or an Adaptor3d_Curve/Adaptor3d_Surface subclass, you must override EvalD0/EvalD1/EvalD2/EvalD3/EvalDN instead. Existing call-site code that consumes Value() / D0..DN continues to work unchanged.
The new EvalRep descriptor system additionally allows alternate evaluation paths to be attached per-object via the Set/Get/Clear EvalRep API (full, derivative-bounded, and parameter-mapped descriptors are supported). This is the mechanism behind, for example, the offset-surface fast path that bypasses the expensive offset evaluation when an equivalent non-offset surface is available.
Adaptor classes for elementary geometry now store gp_* primitives directly in std::variant and dispatch via switch/enum to ElCLib/ElSLib static methods, eliminating virtual calls for elementary geometry on the evaluation hot path.
LProp packages are consolidated and several GProp classes are deprecated.
Geom2dLProp and LProp3d packages are removed and consolidated into the unified GeomLProp template classes (GeomLProp_CLPropsBase, GeomLProp_SLProps). Backward-compatible type aliases for the previous class names are preserved, so most call sites continue to compile unchanged.LProp_AnalyticCurInf is removed (dead code).GProp_EquaType enum is removed (no consumers). Dimensionality analysis is now exposed via PointSetLib_Equation.The point-cloud property classes GProp_PGProps, GProp_PEquation, GProp_CelGProps, GProp_SelGProps, GProp_VelGProps are marked with Standard_HEADER_DEPRECATED("Deprecated since OCCT 8.0.0. Use PointSetLib_Equation instead") (and equivalent messages) in favour of the new PointSetLib package (PointSetLib_Props, PointSetLib_Equation), which is provided in TKMath without inheritance from GProp_GProps.
A new GeomBndLib package provides geometry-aware bounding boxes for all standard Geom curve and surface types via std::variant-based per-type dispatch, with analytical solutions for conics and quadrics and PSO+Powell-based tight BoxOptimal results. BndLib_Add3dCurve, BndLib_AddSurface, and BndLib_Add2dCurve now delegate to GeomBndLib. The public BndLib API is preserved unchanged.
The new ExtremaPC package provides point-to-curve extrema computation with per-geometry specialized evaluators (ExtremaPC_Line, ExtremaPC_Circle, ExtremaPC_Ellipse, ExtremaPC_Hyperbola, ExtremaPC_BezierCurve, ExtremaPC_BSplineCurve, ExtremaPC_OffsetCurve) and an ExtremaPC_Curve aggregator dispatcher.
OCCT 8.0.0 introduces a new graph-based representation of topology and BRep geometry as an alternative to the linked TopoDS_Shape data structure. The foundation is split across two layers:
BRepGraph (public)- typed BRepGraph_NodeId identifiers, multiple Views (TopoView, RefsView, CacheView, BuilderView), bidirectional parent/child explorers (BRepGraph_ChildExplorer, BRepGraph_ParentExplorer, BRepGraph_WireExplorer), iterators (BRepGraph_DefsIterator, BRepGraph_RefsIterator, BRepGraph_RelatedIterator, BRepGraph_CacheKindIterator, BRepGraph_LayerIterator), extensible Layer/Cache system, mutation guards (BRepGraph_MutGuard), history tracking (BRepGraph_History), deduplication (BRepGraph_Deduplicate), compaction (BRepGraph_Compact), deep copy (BRepGraph_Copy), and validation (BRepGraph_Validate).BRepGraphInc (internal)- incidence-table storage with BRepGraphInc_Populate (TopoDS_Shape -> graph) and BRepGraphInc_Reconstruct (graph -> TopoDS_Shape) roundtrip conversion.BRepGraph_Tool is the centralized geometry-access API (analogue of BRep_Tool). BRepGraph_Builder allows programmatic graph construction without an input TopoDS_Shape.
The graph representation is additive in 8.0.0- existing TopoDS_Shape code continues to work unchanged. Application code that wants to opt in can use BRepGraphInc_Populate and BRepGraphInc_Reconstruct to convert in either direction.
The TopoDS_TShape hierarchy has been reworked at the state and dispatch layer:
ShapeType() is non-virtual and embedded in a compact uint16_t bit-packed state field on TopoDS_TShape. Subclasses no longer override ShapeType(); the shape type is stored alongside the orientation/lock/checked/closed/infinite/convex/modified/free flags in the same field.TopAbs::Compose(), Reverse(), and Complement() are inlined noexcept static functions in the TopAbs.hxx header (constexpr lookup tables) rather than out-of-line functions in TopAbs.cxx.This is a binary-incompatible change. Source compatibility is preserved for code that uses the public TopoDS_* and TopExp* APIs. Custom TShape-derived classes that previously overrode ShapeType() must drop the override and rely on the base-class state field.
Child storage on TopoDS_TShape remains NCollection_List<TopoDS_Shape> and TopoDS_Iterator continues to iterate the list - callers that touch myShapes directly do not need to change.
Methods that previously returned occ::handle<> values via output parameters are deprecated in favour of return-by-value overloads in ApplicationFramework, DataExchange, ModelingAlgorithms, ModelingData, and Visualization:
Many handle-returning APIs are now [[nodiscard]].
The legacy DISCRETPLUGIN / DISCRETALGO symbol-based plugin system is replaced with a registry-based factory. The headers BRepMesh_PluginMacro.hxx, BRepMesh_PluginEntryType.hxx, and BRepMesh_FactoryError.hxx are removed, as are the Draw commands mpsetfunctionname, mpgetfunctionname, mperror.
Migrate plugin discovery to the new factory:
BRepMesh_IncrementalMeshFactory is registered for the "FastDiscret" algorithm and XBRepMesh_Factory for the "XBRepMesh" extended meshing algorithm. Loading both TKMesh and TKXMesh no longer causes symbol collisions.
The PLib_Base abstract handle class has been removed. PLib_JacobiPolynomial and PLib_HermitJacobi are now value types (no longer derived from Standard_Transient); their methods are non-virtual and const. Construct them on the stack or as direct members:
PLib_DoubleJacobiPolynomial is removed entirely. There is no direct in-tree replacement- application code that depended on it must be ported manually to a combination of PLib_JacobiPolynomial and PLib_HermitJacobi, or rewritten against the new Geom2dProp / GeomProp differential-property packages where applicable.
The OCCT-specific math wrapper functions are deprecated in favour of the <cmath> / <algorithm> standard library equivalents:
| Deprecated | Replacement |
|---|---|
ACos, ASin, ATan, Cos, Sin, Tan, Cosh, Sinh, Tanh | std::acos, std::asin, ... |
Exp, Log, Pow, Sqrt | std::exp, std::log, std::pow, std::sqrt |
Abs, Sign | std::abs, std::copysign (or < comparison) |
Floor, Ceiling, Round, IntegerPart | std::floor, std::ceil, std::round, std::trunc |
Min, Max | std::min, std::max |
NextAfter | std::nextafter |
The pure virtual StepType() method on StepData_ReadWriteModule now returns const std::string_view& instead of const TCollection_AsciiString&. All subclasses must update their override to match. If your code stored or compared the result against TCollection_AsciiString instances, convert through TCollection_AsciiString(theType.data(), int(theType.size())) or compare against string literals directly.
The legacy immediate-mode rendering methods on AIS_InteractiveContext are deprecated. New code should use the retained-mode pipeline through Display() / Redisplay() and presentation updates. Specific deprecated entry points emit compiler warnings on use.
Standard_Mutex and its Standard_Mutex::Sentry RAII helper are deprecated. Use the standard library:
TopTools_MutexForShapeProvider is removed. Where shape-level locking is needed, allocate a std::mutex directly. Several previously mutex-guarded internals in BRepCheck_* and Foundation globals have been converted to thread_local storage in 8.0.0, which may obviate the lock entirely.
The implicit optimization in OpenGl_Aspects that forced UNLIT shading when a material had no reflection properties has been removed. This was breaking PBR materials, interior color handling, and texture modulation. If your application relied on zero-material properties to obtain UNLIT shading, set the shading model explicitly:
Bnd_Range::IsIntersected() previously returned a magic integer; it now returns the strongly-typed Bnd_Range::IntersectStatus enum:
Several Bnd_* accessors (Center(), Min(), Max(), Get()) now return std::optional. Bnd_* classes have been annotated with [[nodiscard]] and noexcept where appropriate; Contains() and Intersects() wrappers have been added.
GeomAdaptor_TransformedSurface::GeomSurface() is deprecated. Use the new original/transformed surface accessors instead. GeomAdaptor_TransformedCurve has been introduced as a new base class for BRepAdaptor_Curve that wraps a GeomAdaptor_Curve (or Adaptor3d_CurveOnSurface) with an applied gp_Trsf. GeomAdaptor_Surface exposes new ToleranceU() / ToleranceV() accessors.
Geometry hash classes now expose CompTolerance and HashTolerance fields and constructors instead of the previously hard-coded 1e-12 constant. Code that depended on the old constant should explicitly request the previous values via the constructors.
IsClosed() on curves and surfaces previously used gp::Resolution() (~1e-290), making the check practically unusable. It now uses Precision::Computational() (~DBL_EPSILON). Trimmed curves and surfaces now also detect integer-period spans when reporting IsClosed() / IsPeriodic(). Application code that relied on the previous near-zero tolerance must adjust its inputs or its expectations accordingly.
USE_VTK is now OFF by default. Builds that need VIS must opt in explicitly (-DUSE_VTK=ON).USE_RAPIDJSON)** is now an explicit dependency: glTF support is disabled when RapidJSON is not available. Set -DUSE_RAPIDJSON=ON (and ensure RapidJSON is discoverable, or use BUILD_USE_VCPKG=ON) to keep glTF.Overview, RefMan, and doc CMake targets.vcpkg integration**- OCCT ships a vcpkg manifest at adm/vcpkg/ports/opencascade/vcpkg.json (referenced via VCPKG_MANIFEST_DIR). Configure with -DBUILD_USE_VCPKG=ON and the desired USE_* flags; the toolchain file is detected automatically from VCPKG_ROOT. CMake config files are now installed under share/<OCCT_PROJECT_NAME>/ for vcpkg compliance.Register / UnRegister static methods on configuration nodes, with DE_MultiPluginHolder for projects that load multiple providers.Standard_Failure::Raise throughout the OCCT source tree- any custom build system that grepped for Raise( should be updated.Removed (no backward-compatible alias):
| Item | Replacement |
|---|---|
Standard_Failure::Raise(), Instance(), Throw() static methods | throw Standard_Failure(...) |
Standard_ErrorHandler::Catches() / LastCaughtError() | Implicit via execution flow / variant in handler |
NCollection_Map::Seek() / ChangeSeek() | Contained() returning std::optional |
BRepMesh_PluginMacro.hxx, BRepMesh_PluginEntryType.hxx, BRepMesh_FactoryError.hxx | BRepMesh_DiscretAlgoFactory |
Draw commands mpsetfunctionname, mpgetfunctionname, mperror | Not needed with factory pattern |
TColGeom, TColGeom2d packages | NCollection_Array1<occ::handle<Geom*_Curve>> |
Geom2dLProp, LProp3d packages | GeomLProp template classes (aliases preserved) |
LProp_AnalyticCurInf | - |
GProp_EquaType enum | PointSetLib_Equation |
BUC60720 Draw command, QABugs_PresentableObject | - |
PLib_Base abstract class | PLib_JacobiPolynomial / PLib_HermitJacobi as value types |
PLib_DoubleJacobiPolynomial | - (port manually) |
TopTools_MutexForShapeProvider | std::mutex |
OSD_MAllocHook class, mallochook Draw command | Platform tools (Valgrind, AddressSanitizer) |
QANCollection test package | GTest-based tests under src/.../GTests/ |
BUILD_PATCH CMake option | - (apply patches at source level) |
| Legacy Tcl documentation entrypoints | Overview, RefMan, doc CMake targets |
| Inspector, ExpToCas (in-tree) | Separate GitHub repositories |
Deprecated (still compiles with warnings):
| Item | Replacement |
|---|---|
Standard_Failure::GetMessageString() | what() |
Package collection typedefs (TColStd_*, TopTools_*, ...) | NCollection_*<T> |
| BSpline / Bezier copy-out accessor overloads | Const-reference returning versions |
| Convert package single-element accessors | Batch const-reference accessors |
Nullable Weights() | WeightsArray() |
GProp_PGProps, GProp_PEquation, GProp_CelGProps, GProp_SelGProps, GProp_VelGProps | PointSetLib_Props, PointSetLib_Equation |
GeomAdaptor_TransformedSurface::GeomSurface() | Original/transformed surface accessors |
| Handle out-parameter overloads | Return-by-value overloads |
Standard_Mutex (and Standard_Mutex::Sentry) | std::mutex (with std::lock_guard) |
OCCT math wrappers (ACos, Sin, Sqrt, Min, Max, ...) | std:: equivalents in <cmath> / <algorithm> |
Transfer_TransferDeadLoop exception | Status-flag-based dead-loop detection |
AIS_InteractiveContext immediate-mode rendering methods | Retained-mode pipeline |
1.10.0