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Forthcoming OCCT 7.5.0 release extends its real-time rendering engine with a PBR (physically-based rendering) mode. OCCT implements PBR metal-roughness material workflow described by core glTF 2.0 specifications and also includes glTF data exchange components. New functionality opens a door to a new level of realism and visual quality of displayed models, and improves interoperability across various 3D engines supporting the same material workflow.

Before talking about sRGB, lets figure out what was wrong with old OCCT 3D Viewer. Take a look onto a pair of screenshots:

Sphere lighting before (left) and after (right) switching to sRGB-aware renderer.

The left image demonstrates a soft transition of a light into a shadow, while the right one shows more rapid transition. Left image might look softer, but which one is closer to real life?

Mesh displayed in 3D Viewer may come from different sources - imported from external file (glTF, JT, STL, PLY, OBJ), computed for analytical BRep geometry by BRepMesh (part of OCCT) and ExpressMesh (OCC component) algorithms or generated directly by application code.

The mesh is usually displayed shaded, but such a presentation is not suitable for analysis of mesh structure. In many cases, application developer needs other mesh presentations to locate issues (too many details, not enough details, local deviations, etc.) and make corrections based on analysis results (adjust mesh generation or export parameters).

In this case, mesh edges presentation becomes very helpful.

Draw Harness test case for Mesh Edges (Geometry Shader).

We are glad to inform the community of Open CASCADE Technology about a complete overhaul of BRepMesh component that is waiting for release in the upcoming 7.4.0 version. This overhaul, constrained by the requirement to keep non-regression of test cases collected during the last 20 years, took a while. In the end, the entire component has gained a new appearance. The new architecture simplifies the process of mesh generation over OCCT's BRep models and enables processing of some corner cases that were hard to handle before.

Hello,

We are pleased to inform you that the next release of OCCT, 7.3.0, is ready for beta testing, and invite you to test this beta version in your applications.

Use the commit tagged "V7_3_0_beta" in the Git repository for this testing. Alternatively, you can use either complete source archive or Windows installer including ready-to-use binaries built with VS 2010.

The next release of Open CASCADE Technology (7.3.0) will include the new algorithm intended for removal of the selected features from the model. The features that can be removed include holes, protrusions, gaps, chamfers, fillets etc. The defeaturing algorithm can be very useful in different contexts:

• Model simplification for numeric analysis, display on mobile devices, etc;
• In the direct modeling concept where the history of operations is unavailable;
• Removal of the proprietary details of the model before sharing it with others;
• Fixing the certain defects in the model, e.g. filling the gaps, holes etc.

Historically, OCCT 3D Viewer provided two options for dumping view content:

• V3d_View::ToPixMap() saving an image screenshot (bitmap) into formats like PNG, BMP, JPG.
• V3d_View::Export() exporting into vector graphics image format into formats like SVG, PDF, PS.

The latter one was provided with help of an external library gl2ps basing on OpenGL transformations feedback functionality (when OpenGL commands issued for rendering are captured and stored into dedicated buffer).

Development branch of Open CASCADE Technology (will be available in OCCT 7.3.0) introduces a new small feature for analyzing rendering performance issues #0029346.

Graphic3d_RenderingParams structure has been extended with a set of new properties for collecting and displaying performance counters in 3D Viewer.

Local Context was an essential part of OCCT 3D Viewer (AIS_InteractiveContext) for a long time. The concept of Local Context is quite simple and powerful - differentiation of two Viewer states: Neutral Point where all model objects reside, and Local Context augmenting main model presentations with auxiliary ones, created temporarily for particular task in user interaction. Even more, OCCT allows creation of multiple Local Contexts, defining some sort of stack of contexts.