skanti/Scan2CAD — reverse-engineered prompt

Build me a working version of this Scan2CAD project so I can take the Scan2CAD annotations, ScanNet scans, and ShapeNet models, then visualize and run CAD alignment on a sample scene without fighting the setup.

Please make the repo easy to use for someone who is not deep into research code. Add clear setup steps, check for missing data folders, compile the C++ tools, and make simple commands for the main flow: preview annotations, voxelize CAD models, generate correspondences, start the PyTorch training script, run the alignment, and export a mesh I can open and inspect.

If the full datasets are not present, make the scripts fail with helpful messages and point me to where each dataset should go. Use the sample assets if possible so I can confirm everything works before downloading huge data. Clean up any broken paths or old Python issues you find. Look up current docs online if you need to.