orthographic-registration

Orthographic Registration

This skill prevents the common failure where the front view looks plausible but the side/back/top views are wrong.

Coordinate contract

• Front view defines X/Z silhouette.
• Side view defines Y/Z depth envelope.
• Top view defines X/Y spread.
• Back view defines rear silhouette/material only; it must not rewrite the front silhouette.

Workflow

1. Run scripts/register_views.py on the available view images.
2. Create orthographic reference planes/image empties with a single shared scale.
3. Align centerline and bbox centers before modeling.
4. Lock front X/Z boundary vertices.
5. Add Y depth from side/top envelopes using modifiers/displacement or vertex groups.
6. Validate all four cameras before export.

Failure policy

If views disagree, front brand read wins. Document the conflict in registration_report.json.

Front-plane rotation rule

In this Blender coordinate convention, the front camera looks along the Y axis and the reference silhouette lives in the X/Z plane. Therefore 2D rotations inside the front view are rotations around the Y axis, not around Z. Use rotation_euler = (0, angle, 0) for 2D component orientation in the front projection. Z rotation spins objects into/out of screen-space incorrectly for X/Z-plane meshes.

Sources distilled

• Blender Image Empty/reference image controls for orthographic blueprints.
• OpenCV homography/alignment and geometric transforms for view registration.