Open CASCADE Technology Version 8.0.0 Release Candidate 2

Open Cascade is delighted to announce the release of Open CASCADE Technology version 8.0.0 Release Candidate 2 to the public.

(Release Candidate 1: https://github.com/Open-Cascade-SAS/OCCT/releases/tag/V8_0_0_rc1)

Overview

Version V8_0_0_rc2 is a candidate release incorporating over 80 improvements and bug fixes compared to version V8_0_0_rc1, bringing the total improvements since version 7.9.0 to over 130 changes.

What is a Release Candidate

A Release Candidate is a tag on the master branch that has completed all test rounds and is stable to use.
Release candidates progress in parallel with maintenance releases, with the difference that maintenance releases remain binary compatible with minor releases and cannot include most improvements.
The cycle for a release candidate is planned to be 5-10 weeks, while maintenance releases occur once per quarter.

What's New in OCCT 8.0.0-rc2

Core

Upgraded minimum C++ version requirement to C++17 #537
Geometric Classes Optimization: Significantly optimized gp_Vec, gp_Vec2d, gp_XY, and gp_XYZ classes by simplifying mathematical computations, replacing indirect API calls with direct data member access in performance-critical sections, and improving matrix operations including inversion, transposition, and power calculations #578
Reworked atomic and Standard_Condition implementation #598
Optimized NCollection_Array1 with type-specific improvements #608
Reworked math_DoubleTab to use NCollection container #607
Fixed WinAPI resource leaks #625
Fixed include brackets type issues #635
Geom package copy optimization #645

Build System and Configuration

Comprehensive VCPKG Support: Added full VCPKG layout configuration with CMake file placement in share/ directory for compliance, introduced OCCT_PROJECT_NAME parameter for customizing directory structure, and updated environment scripts while maintaining backward compatibility #618, #637, #638
Added VCPKG port opencascade with TclTk and GTest support #580, #616
Implemented flexible project root configuration #641
Fixed build config file validation issues #647
Disabled GLTF build without RapidJSON #646
Fixed link errors on macOS when not building using vcpkg #609
Fixed CSF variable overwriting issues #561
Fixed paths to 3rd-party in cmake configuration #523
Fixed ARCH detection for older 32-bit Macs #626
Removed unused CMake scripts and dependencies #644, #581
Fixed samples CMake configuration #643

Modeling

New Helix Toolkit: Implemented a complete TKHelix toolkit with geometric helix curve adaptor and topological builders, featuring advanced B-spline approximation algorithms for high-quality helix representation and comprehensive TCL command interface #648
Added option to not build history in BRepFill_PipeShell #632
Fixed GeomFill_CorrectedFrenet hanging in some cases #630
Fixed infinite loop in Simplifying Fuse operation #557
Fixed Bnd_BoundSortBox::Compare failures in some cases #518
General Fuse Optimization: Improved BOPAlgo_PaveFiller performance by adding null checks for triangulation in BRep_Tool::IsClosed, simplifying index lookup logic in BOPDS_DS, and introducing helper functions for better clarity and robustness #514
Fixed BRepFilletAPI_MakeFiller segfault with two curves and rim #532
Fixed mismatch between projected point and parameter in ShapeAnalysis_Curve #600

Shape Healing

Implemented reusing Surface Analysis for Wire fixing #565

Visualization

Enhanced FFmpeg Compatibility Layer and updated Video Recorder #582
Fixed binary PPM image comment writing in Image_AlienPixMap #413c08272b
Updated Graphic3d_Aspects::PolygonOffsets documentation #519
Marked Immediate Mode rendering methods as deprecated in AIS_InteractiveContext #521

Data Exchange

Fixed GLTF indices parsing during array processing #602
Implemented non-uniform scaling in GLTF Import #503
Fixed GLTF saving edges when Merge Faces is enabled #554
Changed GLTF export line type to LINE_STRIP #535
Fixed missing GDT values in STP Import #617
Preserved control directives in Step Export #601
Ignored unit factors during tessellation export #577
Applied scaling transformation in Step Export #513
Fixed missing Model Curves in IGES Export transfer cache #483
Fixed XCAFDoc_Editor::RescaleGeometry not rescaling translation of roots reference #529
Fixed facets with empty normals handling in RWObj_Reader #520
Added conversion utilities for STEP geometrical and visual enumerations #545
Added missing headers #530
Optimized StepData_StepReaderData #543
Optimized entity graph evaluating #562
Removed GLTF files from XDEDRAW #649
Removed unused dependencies from TKXDEDRAW #650

Testing

Updated GitHub Actions to use latest versions #640
Added performance summary posting to PR #612
Fixed master validation workflow #611
Added daily vcpkg package validation #605
Updated samples C++ version #606
Removed extra GitHub jobs #594
Added ASCII code validation #593
Migrated PR actions to VCPKG-based #587
Added compilation on Clang without PCH #540
Enabled IR integration concurrency #531, #536

Draw and Tools

Fixed vcomputehlr misprint leading to error if no Viewer #526
Updated DrawDefault script to handle missing directory cases #542

Documentation

Added missing description to HLRBRep_HLRToShape methods #525
Added Copilot instructions for OCCT development #589

How to Upgrade

There are no critical breaking changes at the API level, however note the following:

C++17 Requirement: The minimum C++ version has been upgraded to C++17. Ensure your compiler supports this standard.
Deprecated Methods: Some Immediate Mode rendering methods in AIS_InteractiveContext have been marked as deprecated.

Migration should proceed smoothly for most applications.

Performance Improvements

This release includes several significant performance optimizations:

Geometric Classes: Major performance improvements in gp_Vec, gp_Vec2d, gp_XY, and gp_XYZ classes through direct data access and simplified computations
Boolean Operations: General Fuse algorithm optimization with improved index lookup and null safety checks
Memory Management: Geom package copy optimization and NCollection_Array1 type-specific improvements
Data Exchange: StepData_StepReaderData optimization for faster STEP file processing
Foundation Classes: math_DoubleTab rework using NCollection containers for better memory efficiency

New Contributors

@iosdevzone made their first contribution in #609

Full Changelog: V8_0_0_rc1...V8_0_0_rc2

Open-Cascade-SAS/OCCT V8_0_0_rc2 on GitHub