What is a .BREP file?
BREP is a boundary-representation CAD format describing exact solid geometry (OpenCASCADE).
- Did you know
- Boundary representation has been the core way CAD kernels describe solids since the 1970s.
- A BREP describes a solid by its exact boundary - faces, edges and vertices bound to precise surfaces and curves - rather than approximating it with triangles like STL.
- Its surfaces can include true mathematical forms such as NURBS, so a BREP cylinder is genuinely round instead of a many-sided mesh.
- BREP is the native solid-model format of the Open CASCADE CAD kernel, which also reads and writes the neutral STEP and IGES exchange formats.
- Boundary representation has underpinned mainstream CAD modelling kernels since the 1970s, making it one of the oldest ideas in solid modelling still in daily use.
- What Analyser shows you
- View STL, OBJ, PLY, OFF, STEP, IGES, BREP, 3MF and AMF models in an interactive WebGL viewer with triangle count, bounding box, surface area and volume. STEP/IGES/BREP are tessellated with OpenCASCADE and STEP shows its originating CAD system, version and AP203/214/242 protocol; 3MF and AMF let you inspect each model and assembly on the build plate individually.
- Open a .BREP file
- Drag a .BREP file onto the Analyser home page (or tap to pick one). It opens entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.