Converting manufacturer CAD files to glTF for fast browser loading

Real manufacturer CAD files often fail to load quickly in a browser, even when the Three.js demo appears simple. Exported CAD models are typically very large, commonly 40 to 120MB per variant, and arrive with Z-up orientation, unit scale mismatches, CAD-specific materials, and thousands of separate parts. The author's pipeline first merges parts and removes hidden geometry in Blender, then fixes orientation and scale and assigns PBR materials by slot. Finally, Draco and KTX2 compression shrink files to roughly 2 to 5MB without visible quality loss. Because models change and each product line needs repeated processing, the author treats this pipeline as an ongoing project cost, automated with scripts or queue jobs.