https://dkopa.com/log Engineering GPU and CAD tools for the browser. https://dkopa.com/log/cad-viewer/building-a-cad-viewer/ https://dkopa.com/log/cad-viewer/building-a-cad-viewer/ Wed, 28 Oct 2026 00:00:00 GMT First entry in the DKOPA devlog: a fast STEP viewer running entirely client-side on WASM, headed for WebGPU. cad-viewer https://dkopa.com/log/cad-viewer/first-triangle/ https://dkopa.com/log/cad-viewer/first-triangle/ Wed, 28 Oct 2026 00:00:00 GMT The viewer scaffold is live at /viewer — drop a .step file and it parses entirely in your browser. Here's how the pipeline works. cad-viewer https://dkopa.com/log/cad-viewer/parts-and-edges/ https://dkopa.com/log/cad-viewer/parts-and-edges/ Wed, 28 Oct 2026 00:00:00 GMT Second milestone: the viewer now shows the part structure from your STEP file and renders teal edge outlines. Also — IGES and BREP support snuck in. cad-viewer https://dkopa.com/log/cad-viewer/section-plane/ https://dkopa.com/log/cad-viewer/section-plane/ Wed, 28 Oct 2026 00:00:00 GMT Third milestone: a clipping plane that sweeps through the model on any axis. Almost free in Three.js — here's how it works and what it doesn't do yet. cad-viewer https://dkopa.com/log/cad-viewer/face-picking/ https://dkopa.com/log/cad-viewer/face-picking/ Wed, 28 Oct 2026 00:00:00 GMT Fourth milestone: click any face in the viewer and the actual B-rep face highlights — not the triangle you hit. Here's the data path that makes it work. cad-viewer https://dkopa.com/log/cad-viewer/measurements/ https://dkopa.com/log/cad-viewer/measurements/ Wed, 28 Oct 2026 00:00:00 GMT Fifth milestone: the viewer measures point-to-point distances — two clicks on the model, a line between them, and a live label that follows you around the scene. cad-viewer https://dkopa.com/log/cad-viewer/brep-edges/ https://dkopa.com/log/cad-viewer/brep-edges/ Wed, 28 Oct 2026 00:00:00 GMT Sixth milestone: edge lines now come from the B-rep's own face structure — every edge shown is a real CAD edge, and the extraction is one observation plus a hash map. cad-viewer https://dkopa.com/log/cad-viewer/webgpu/ https://dkopa.com/log/cad-viewer/webgpu/ Wed, 28 Oct 2026 00:00:00 GMT Seventh milestone: the viewer now renders on WebGPU where available, falling back to WebGL2 automatically. The swap was three lines — here's why it took seven posts to get here. cad-viewer https://dkopa.com/log/cad-viewer/section-caps/ https://dkopa.com/log/cad-viewer/section-caps/ Wed, 28 Oct 2026 00:00:00 GMT Eighth milestone: clipped models now show solid faces where the section plane cuts through, instead of a hollow shell. It was the honest hard problem on the list — here's the mesh-level version. cad-viewer https://dkopa.com/log/cad-viewer/edge-measurement/ https://dkopa.com/log/cad-viewer/edge-measurement/ Wed, 28 Oct 2026 00:00:00 GMT Ninth milestone: click an edge in the viewer and get its length — the whole B-rep edge chain, not the segment under your cursor. The interesting part is splitting the wireframe graph at junctions. cad-viewer https://dkopa.com/log/cad-viewer/mesh-formats/ https://dkopa.com/log/cad-viewer/mesh-formats/ Wed, 28 Oct 2026 00:00:00 GMT Tenth milestone: the viewer takes .stl and .obj files. Easy to load — the interesting part is honestly degrading the features that need B-rep data the formats don't carry. cad-viewer