tile-import-verification

name	tile-import-verification
description	Step-by-step verification of PLY tile imports from Metashape - naming, transforms, bounding boxes, and grid coverage.

Tile Import Verification

Overview

Verifies that tiles imported from Metashape are correct before processing begins. Catches naming violations, transform issues, and missing tiles early.

Pre-Flight Checklist

• PLY directory path confirmed
• Expected tile count known (from Metashape export)
• Metashape chunk bounds available for comparison (optional)

Workflow

Step 1: Import Tiles

1. Call batch_import(directory="/path/to/ply/dir", format="ply")
2. Record the per-tile results and tile grid summary

Step 2: Verify Naming

1. Check every imported object follows Tile_X-Y naming
2. If any objects have non-standard names, rename them to match the filename

Step 3: Verify Identity Transforms

1. For each tile, check identity_transform from import results
2. ALL tiles MUST have identity transforms
3. If any don't: DO NOT PROCEED - transforms must be fixed first

Step 4: Verify Bounding Boxes

1. Call get_mesh_stats on each tile
2. Check bounding box dimensions are reasonable (not degenerate)
3. If Metashape chunk bounds are available, compare:
   • Tile bounding boxes should fit within chunk bounds
   • Total coverage should roughly match chunk extent
4. Check for overlapping tiles (bounding boxes that intersect significantly)

Step 5: Grid Coverage

1. Review tile grid summary
2. Report grid dimensions (NxM)
3. Report any gaps (missing tiles in the grid)
4. Gaps are warnings, not blockers

Step 6: Save

1. save_file after successful verification

Pass/Fail Criteria

PASS if:

• All tiles named Tile_X-Y
• All tiles have identity transforms
• All tiles have > 1000 faces
• No degenerate bounding boxes

FAIL if:

• Any tile has non-identity transform
• Any tile has 0 faces
• Import errors on any file

Common Pitfalls

• Wrong CRS in Metashape export: Tiles may be 1000x too large or too small. Check bounding box dimensions are in meters.
• FBX axis confusion: If importing FBX instead of PLY, axis convention may cause rotation. Always prefer PLY for the initial import.
• Duplicate names: Blender appends .001 to duplicate names. If this happens, the source files may have naming conflicts.