Open-Cascade-SAS/OCCT V8_0_0_beta2

on GitHub

Open Cascade is pleased to announce the release of Open CASCADE Technology version 8.0.0 Beta 2 to the public.

• Beta 1
• Release Candidate 5
• Release Candidate 4
• Release Candidate 3
• Release Candidate 2
• Release Candidate 1

Overview

Beta 2 is a small follow-up to Beta 1 addressing two issues raised during the Beta soak: thread-safety crashes in the STEP/IGES read and STEP write pipelines, and the loss of the classical CPU grid backend. It also ships the 8.0.0 documentation refresh and a new top-level samples/ slot.

No new features, no API breakage beyond what Beta 1 already announced. Final 8.0.0 release remains planned for May 7, 2026.

Highlights

• Thread-safe STEP write and STEP/IGES read #1259 - fixes libmalloc double-free under concurrent STEPControl_Writer::Transfer and intermittent crashes in concurrent STEP/IGES readers. Contract: one reader/writer per thread; STEP read and write safe under that contract, IGES read is not.
• CPU grid path restored alongside the shader grid #1252 - the classical Graphic3d_Structure-based grid removed in Beta 1 (#1223) is back as a coexisting backend for legacy GL profiles and embedded targets. Snap math unchanged; backends mutually exclusive per view.
• Documentation modernized for 8.0.0 #1256 - GitHub-native workflow, vcpkg build, C++17 baseline, full 8.0.0 upgrade guide; obsolete Mantis/Gitolite/Inspector/DFBrowser pages removed.
• Top-level samples/ directory #1257 - new README points to the external samples repository and browsable site.
• CI warning cleanup #1253 - NULL -> nullptr sweep in OpenGL files plus macOS / Ubuntu warning fixes under the Beta 1 -Werror baseline.

Migration

Beta 2 introduces no new API breakage. Beta 1 migration material applies unchanged. Two additions to keep in mind:

• STEP/IGES concurrency: STEP read and write are safe with one instance per thread (default parameter set). IGES read is not supported concurrently - serialize it.
• Grid backend: existing V3d_View::SetGrid / V3d_Viewer::ActivateGrid calls resolve to the restored CPU path again. V3d_View::GridDisplay(Aspect_GridParams, ...) remains the shader path. Activating one erases the other on the same view.

Full Changelog: V8_0_0_beta1...V8_0_0_beta2