What is a .BREP file?
BREP is a boundary-representation CAD format describing exact solid geometry (OpenCASCADE).
- Did you know
- 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, AMF and glTF/GLB models in an interactive WebGL viewer with orbit, orthographic or perspective projection, a wireframe topology overlay, an orientation cube, triangle count, bounding box, surface area and volume. glTF 2.0 and binary GLB scenes are parsed natively - the node graph is flattened, mesh geometry shown, and the authoring tool, version and mesh/material/animation counts read. 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. Wavefront material libraries (MTL) are broken out into each material with its colours, shininess, opacity and the texture files it references.
- 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.