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, and any pictures a 3MF package carries - its own thumbnail, the build-plate renders slicers such as Bambu Studio and OrcaSlicer write, and texture maps - are extracted and shown with it. 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.