3D viewer

cadvm view HEAD~1 HEAD --open

cadvm view turns a geometric diff into a single self-contained HTML file with a hand-written WebGL renderer — no CDN, no server, fully offline. Open it in any modern browser.

What you see

Each face of the part is colored by how it changed:

• grey — unchanged (the face exists in both versions);
• green — added (a face of the new version with no match in the old one);
• red — removed (a face of the old version, gone in the new one).

So you see exactly which faces changed on the real part. Each layer can be toggled in the side panel.

Controls: drag to rotate · scroll to zoom · toggle layers with the checkboxes.

Options

cadvm view HEAD~1 HEAD                 # if exactly one file changed
cadvm view HEAD~1 HEAD -- piece.step   # pick the file when several changed
cadvm view HEAD~1 HEAD -o diff.html    # choose the output path
cadvm view HEAD~1 HEAD --open          # also open in the default browser

You can also launch it straight from the TUI with the v key.

STEP/STP vs STL/OBJ

• STEP/STP (B-Rep): the cadvm-geom helper classifies each face by its underlying surface and tessellates them — needs Open CASCADE.
• STL/OBJ (mesh): cadvm diffs the triangles directly in pure Rust (no Open CASCADE). Each triangle of the new mesh is unchanged if it lies on the old surface (point-to-triangle distance) and added otherwise; old triangles with nothing nearby in the new mesh are removed. So view works on meshes even without the helper installed.

Both paths emit the same unchanged/added/removed layers, so the viewer is identical.

Under the hood

The classifier emits flat-shaded, per-color triangle layers as JSON; cadvm embeds that into the HTML template (cadvm-cli/src/viewer.rs) and the WebGL code renders it with per-layer colors and transparency.