# COLMAP Config

Trimmed from `colmap_default.yaml`. Same YAML format as the original — copy the block
below into a `.yaml` file to use it.

Removed on purpose: experiment block, all feature extraction/matching detail except the
GPU switches, all input/output path blocks, Hydra settings. Paths must now be supplied
by the caller (CLI override, or a wrapper config) — this file alone is not runnable.

```yaml
# ── Pipeline flags ────────────────────────────────────────────────────────────
random_seed: 0

# ── Stage toggles (can also be driven by pipeline.yaml) ───────────────────────
run:
  colmap_feat_extract_match: true
  colmap_reconstruct: true

# ── Feature extraction / matching ─────────────────────────────────────────────
# GPU instead of CPU. All other extraction/matching options dropped -> COLMAP defaults.
feat_extract_match:
  extraction:
    device: cuda
  matching:
    use_gpu: true

# ── Reconstruction ────────────────────────────────────────────────────────────
# Priors are loaded as a STARTING POINT only, not frozen: COLMAP refines both poses
# and intrinsics during bundle adjustment and may move them away from the priors.
reconstruction:
  mode: automatic              # triangulate | automatic
  load_prior_poses: true       # automatic mode only: seed with known robot poses
  load_prior_intrinsics: true  # seed with known camera intrinsics
  refine_intrinsics: true      # keep true -> intrinsics stay free, not locked to prior
  mapping_params:
    min_focal_length_ratio: 0.1
    max_focal_length_ratio: 10.0
    max_extra_param: .inf
    ba_local_max_num_iterations: 30
    ba_local_max_refinements: 3
    ba_global_max_num_iterations: 75
    num_threads: 1
```

## Notes for whoever runs this

- **`mode: automatic` is required for the pose priors.** `load_prior_poses` is
  ignored in `triangulate` mode, per the original comment. Changing `mode` silently
  drops the pose priors.
- **"Don't freeze" is `refine_intrinsics: true`.** Setting it to `false` pins intrinsics
  to the prior values, which is the opposite of what this config is for.
- **`ba_use_gpu` is deliberately absent** from `mapping_params` — bundle adjustment is left
  to whatever the implementation defaults to. Only feature extraction and matching are
  pinned to GPU. Do not add a `ba_use_gpu` key back in.