Apple has just released its first generation of ARM-based desktop computers. Macs used exclusively Intel CPUs since transition from IBM PowerPC in 2006, but now Apple believes that their own SoC, originally developed for mobile devices (iPhone and iPad), can replace Intel CPUs within the whole line of products in just 2 years!

Apple M1 SoC became the heart of several low-end devices within the ‘2020 line of products, but Apple promises an outstanding performance difference compared to previous Intel-based generation of products. This is difficult to believe! Could this be true?

Hello,

We are pleased to inform you that the new release of OCCT, 7.5.0, is ready for beta testing, and invite you to test this beta version in your applications.

Use the commit tagged "V7_5_0_beta" in the Git repository for this testing. Alternatively, you can use the complete source archive or Windows installer including ready-to-use binaries built with VS 2017.

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).

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.

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).

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.

Hello,

We are pleased to inform you that OCCT 7.2.0 is ready for beta testing, and invite you to test this beta version in your applications.

Use the commit tagged "V7_2_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 version 7.0 of Open CASCADE Technology features the new General Fuse (GF) based algorithm - Cells Builder. The algorithm can be very useful if you have to perform several standard Boolean operations such as CUT, COMMON and FUSE on the same shapes to obtain the final result.

Due to the possibility to get any split parts of the arguments (parts of the input shapes split in the places of intersection with other input shapes), which are called Cells (that’s where the name for the algorithm comes from), the Cells Builder may significantly simplify and speed up these operations as all intersections will be performed in a single run. In effect, the Cells Builder allows executing the Boolean expressions on the shapes, i.e. performing a sequence of standard Boolean operations in one operation.

The first version of the algorithm (available since OCCT 7.0) had limited capabilities. It worked only with the shapes of the same dimension - only VERTICES, or only EDGES, etc. Recently, the algorithm has been extended to also work with multi-dimensional input shapes. The next version of Open CASCADE (7.2) will feature this extension.

The next release of Open CASCADE Technology will feature the new mode of Boolean Operations - Gluing mode. It is implemented as an option for the algorithms in Boolean Component such as General Fuse, Boolean, Section, Volume Maker and Cells Builder operations. This option has been designed to speed up the computation of the intersection part of the algorithms for the special cases where the arguments do not really interfere each other, but are just touching or overlapping.

In the past, graphic card in computer was designed to perform limited set of operations. At some point, all cards had to provide the hardware-accelerated functionality called Transformation and Lighting (T&L). Application developers had to implement all features and visual effects that were not parts of the fixed set of graphic card functionality on CPU.

Hello,

We are pleased to announce that beta testing campaign of OCCT 7.0 has finished, and OCCT 7.0.0 Release Candidate is available.

This time beta testing was especially fruitful: we have got several dozens inputs from the community, which helped to improve OCCT for this release. The most essential changes since beta version are:

Stereoscopic rendering has been first introduced in Open CASCADE Technology 6.8.0. Initial support has been limited to shutter glasses and off-screen rendering. OCCT 6.9.1 improves this functionality and extends the list of supported consumer display devices.

Dear All,

We have finalized development of several major new features for Open CASCADE Technology 7.0. The most essential changes -- removal of CDL and WOK -- have been raised to master branch of the OCCT Git repository last Friday, and we propose this version for public review, as "alpha" version of OCCT 7.0.

This article is aimed to give overview of the major changes already integrated, and give idea of the effort required to port existing code on the new version.

Preface

One of the most breaking changes in visualization component in OCCT 6.9.0 is complete reconsideration of selection mechanism. The new algorithm is designed to improve performance of dynamic selection of complex scenes by using effective 3D acceleration structures which are built only once and are autonomous from the camera.

Hi All,
At the moment OCCT OCAF persistence uses plugin mechanism, when library providing persistent functionality for particular subset of OCAF attributes is loaded dynamically at runtime by OCAF. For that, the plugin library name and location must be properly defined with help of predefined set of environment variables and resource files.
This system is quite complex and not transparent, especially for beginners.

Dear All,

I am pleased to inform you that OCCT 6.9.0 is ready for public beta testing.

We invite you to test this beta version in your applications. If you have reported some issues in bug tracker, please check those with Verified status -- we assume they are fixed, and will appreciate to see your comments in the notes of the issue. If you detect a regression, please report it as soon as possible.

1. Introduction

The Boolean Operator of Open CASCADE (≤6.8.0) allows treating of two and only two arguments (shapes) to process [1]: S1 (Object), S2 (Tool).

In modeling tasks the very frequent situation is when multiple shapes are to be processed from both sides, Object and Tool. For example, when we have to make in a body of Object multiple cutouts, we need to pass to the Boolean Operator one shape as the Object and a set of shapes as a Tool. The developer has to organize a cycle for repetitive cut from the Object shapes of the Tool one by one. Besides the fact that it is inconvenient for the developer, it applies additional extra expenses in the form of auxiliary temporary data structures that are filled in each instance of Boolean Operator.

1. Introduction

Next version of OCCT will feature new mode of Boolean Operation Algorithm (BOA), called "Fuzzy".

Fuzzy Boolean operations are the type of Boolean operations in which additional user-specified tolerance is used. This mode allows Boolean operations to handle robustly cases of touching and near-coincident entities of the argument shapes.

Hello All,

The release of OCCT 6.8.0 is published. The corresponding tag in Git is "V6_8_0". Note that WOK has also been changed, its version is also elevated to 6.8.0.

Starting from version 6.8.0 OCCT will include one more algorithm for solving global optimization problems.

Its development has been triggered by insufficient performance and robustness of the existing algorithm of minimization of curve - surface distance in Extrema package (class Extrema_GenExtCS). Recent attempts to fix problems in that algorithm led to severe reduction of its performance, hence the need of a different approach raised.

Hello,

We are steadily progressing in the refactoring tasks, and now have the first version of OCCT without WOK and CDL ready for review: see Git branch CR0_noCDL. Note that this is the first experimental version, thus please do not try to use it in your project!

Here is some detail on the changes made in this branch.

Removal of generic classes

TCollection instances have been converted to NCollection templates, except a few instances found in nested generic classes -- these are to be converted manually later.

Run-Time Type Information (RTTI) is C++ mechanism to access type information in code at runtime, including well-known dynamic_cast operator. Although this functionality is integral part of modern C++ standard, this was not true at OCCT foundation time. This is why OCCT has been designed with own RTTI implementation.

Since any modern C++ compiler has built-in RTTI support, many users complain - why OCCT still uses their own implementation? Well, migration to built-in C++ mechanisms would require significant changes due to design differences. However this article covers another aspect of such possible migration - performance comparison.

Hello,

This year we are going to concentrate first on a task which perhaps is the longest-pending one in OCCT development - overall refactoring of the code and build system, getting rid of WOK and CDL.

This change will form a basis of the next OCCT version, 7.0.

Hello All,

During preparation of OCCT 6.7.0 we have made some improvements related to performance and stability of the code which I would like to describe here.

Inspired by advice of our contributors, we have checked possibility to improve performance by tweaking relevant compiler options. The analysis was limited to Visual Studio compilers (used by most of our customers). Here is a summary chart comparing different versions of VC++ on OCCT code.

Problem context

This topic was extracted from OCCT Mantis issue 24324 to involve wider audience into the discussion.

Enabling anti-aliasing with help of V3d_View::SetAntialiasingOn() call for a scene containing shaded polygons often results in problems illustrated by the snapshot below:

OCCT 6.7.0 introduces several major improvements of the visualization component. One of the most breaking changes in OCCT visualization concerns simplified implementation of ray tracing algorithm for regular OCCT visualization primitives. This algorithm is implemented using OpenCL. Being a part of TKOpenGl library, it is fully integrated with standard OCCT visualization logic. From now on, ray tracing can be used as alternative rendering method instead of OpenGL rasterization.

Clipping visualized 3D models with user-defined clipping planes is one of basic OpenGL features that allows the user to look inside the models.

However, in some cases it is more interesting to investigate the cross-section shape rather than the model's internals. For this purpose, the cross-section should be visualized in shading using some distinctive visual attributes (specific color, hatching).

Hello all,

We are moving further in OCCT development, and since today the information on on-going efforts will be made available to the community via the new section Projects of this portal. Check the project pages to see how OCCT will evolve in the nearest future, and consider subscribing to the pages to get mail notifications on updates.

Dear Contributors,

Today we have announced a maintenance release 6.5.5 of OCCT libraries, intended for our customers and users who need an improved version of OCCT compatible with 6.5.4.

Now I am pleased to inform you that the next minor version 6.6.0 is ready for beta testing.

This version provides changes and new features aimed to form a basis for further development:

• Official support of Mac OS X, including use of native Cocoa API (instead of X11).
  

Dear Contributors,

I am glad to announce that the next maintenance release 6.5.4 of OCCT libraries is planned for the beginning of November. The goal of this release is to provide a stable version incorporating bug fixes and improvements made since previous release 6.5.3 (more than 200 changes). Other improvements and new features being currently developed will be included in another release to be done before the end of the year (more details will come soon).