OCCT knowledge archive
Browse historical questions, implementation notes, examples, and answers from the public OCCT community forum.
Search the archive
The search index is loaded only when you start searching. No query is sent to a server.
Public issue archive
Search 7,498 public and community issue records. Participants and tracker identifiers are anonymized independently within each record.
Browse by area
Start with the OCCT subsystem or community area closest to the question.
OCCT usage, algorithms, data exchange, visualization, samples, and build questions.
Release announcements and official notices.
Contribution workflow, roadmap, refactoring, and project collaboration.
Project-specific discussions and external ecosystem usage.
Latest archived activity
This archive is read-only. New OCCT issues should be reported through the current GitHub project.
Other announcements
Dear OCCT community, We would like to inform you about upcoming changes to the Open CASCADE Technology collaborative development portal at dev.opencascade.org . In the coming weeks, the website and its public forum will be switched to read-only mode . After this change, it will no longer be possible
Visualization and 3D Viewer
Using PrsDim_LengthDimension is there a way to customize only the helper/flyout lines? What I want to achieve is this: From the center of the object the helper line should be dotted. The arrow line with the calculated distance should be solid.
OCCT releases
Open Cascade is delighted to announce the final release of Open CASCADE Technology version 8.0.0 to the public. 8.0.0 is the largest single-version step in OCCT in many years. The cycle covered five Release Candidates and three Beta builds and accumulated more than 500 changes since 7.9.0. More deta
Modeling Data and Algorithms
Hello, maybe this isn't the right place to write this but I currently face a very weird issue/bug and I think it has to do with the OpenCASCADE kernel modeling, but I would like for someone else to confirm that maybe using another design tool. I am creating 2 parts and 1 hole: I want to fuse part 1
Data Exchange and Application Framework
Hello, I updated to the latest master branch, and am trying to save STEP files as GLTF, which would would include the edges (as was implemented here ). The way I'm doing this is by opening the document, meshing with BRepMesh_IncrementalMesh , then saving with RWGltf_CafWriter::Perform . I tried open
Visualization
I am currently using AIS_RubberBand to display a selection rectangle on the screen. However, when the View's width is significantly longer than its height (approximately a 4:1 aspect ratio), the Rubber Band is visualized in the wrong position. This issue is also reproducible in the standard Sample w
OCCT releases
Open Cascade is delighted to announce the release of Open CASCADE Technology version 8.0.0 Release Candidate 5 to the public. Release Candidate 4 Release Candidate 3 Release Candidate 2 Release Candidate 1 Overview Version 8.0.0-rc5 is a candidate release incorporating 64 improvements and bug fixes
Open Cascade Applications
I'm developing a rust application, and part of that process is developing the bindings. I'm kinda learning as I go. I was wondering if anyone could share some advice on what bindings to prioritize, and if there is a discussion hub that is active specifically on the topic of app development?
Unsorted projects
I'm in the process if building a CAD app that I feel is a pleasure to use. For me, that means writing it in Rust. For now, that project is private until I feel comfortable sharing, but I'm working on a binding library in parallel. https://github.com/occt-rs/occt-rs I've only spent a day on _this_ re
Open Cascade Applications
Dear community, We are pleased to introduce CascadeScope - a project built for internal debugging and as a demonstration of the power of BRepGraph . CascadeScope is a GUI application that uses BRepGraph as its core representation, with all algorithms built on top of it. Repository: https://github.co
Visualization and 3D Viewer
How to remove the white background of a symbol when outputting using OpenCascade's AIS_Textlabel? Hello everyone, I'm implementing a program for working with shapes using OpenCascade. Please help me remove the white background around a symbol when outputting symbols using OpenCascade's AIS_Textlabel
Modeling Data and Algorithms
There is a shape (.brep is attached) made of a torus surface and four 1-degree B-spline p-curves. 3d-curves generated by BRepLib::BuildCurve3d. Despite the fact that these p-curves are, in fact, iso-curves, the generated 3d curves are also B-splines. The rendering (tesselation) quality of this shape