COMPARISON.md — Canonical Runtime Summary

The repository now keeps one active environment runtime only:

Runtime	Role	Status
SdfDagBackend	GPU-resident batched ray execution over compiled .gmdag scenes	Canonical

Supporting domains:

• projects/voxel-dag compiles source scenes into .gmdag assets
• projects/torch-sdf executes CUDA sphere tracing
• projects/environment preserves the actor-facing DistanceMatrix contract

Historical mesh, voxel, habitat, and sparse-Zarr paths have been removed from the active repository runtime.