Mesh Autopsy

Inspect local 3D geometry with wireframe, topology diagnostics, normals, clipping, explode and compare views.

Mesh Autopsy is an offline geometry inspection bench for OBJ, STL, GLB, and glTF 2.0 models. Choose or drop a model and the extension parses its geometry locally, analyses topology in a Web Worker, and renders the result in WebGL2. The viewport supports orbit, pan, zoom, reset, and six inspection modes. Solid shows the model with local lighting. Wire exposes triangle edges. Topology applies an irregularity heat signal based on triangle-area variation and high local valence. Normals draws a bounded sample of face-normal directions. Slice clips the specimen along X, Y, or Z. Explode separates named groups away from the specimen centroid. A specimen record reports vertex and triangle counts, group count, bounds, open edges, non-manifold edges, degenerate triangles, and index-connected islands. Group Isolation can display a specific OBJ group or glTF primitive. A second model can be loaded as an aligned wireframe compare overlay for quick visual comparison. OBJ polygon faces are triangulated locally. Binary and ASCII STL are supported. GLB and glTF 2.0 triangle primitives are supported, including local node transforms and external .bin buffers when the user selects the .gltf and its buffer together. The extension does not fetch external glTF resources from the network. Draco-compressed geometry, sparse accessors, and non-triangle primitive modes are deliberately rejected or skipped rather than approximated silently. Safety limits keep analysis bounded: the primary file is capped at 220 MB and topology analysis is capped at 1.5 million triangles. Very dense wireframe and normal helpers are sampled to protect browser responsiveness while the original solid geometry remains intact. Mesh Autopsy does not modify, upload, or persist the selected model. Clearing the specimen or closing the tab releases the in-memory and GPU representation.