texture-driven-mesh-fitting

MCP backend

Use when: Texture-driven geometry fitting, mesh boundary fitting to atlas masks, UV-preserving contour correspondence, point/landmark deformation, source mask to mesh repair.

Before the first Blender call, read ../text-to-blender/references/mcp-backends.md. Prefer official MCP for shared capabilities; preserve the selected backend for the whole task. Tool names in recipes are client/legacy examples: map them through that reference and its agent-host guide.

Texture-Driven Mesh Fitting

This skill fixes the common failure: a texture is mapped correctly, but the mesh silhouette underneath is wrong. The mesh adapts to the source contour; the texture is not stretched to hide a wrong mesh.

Preconditions

• Structural parts are segmented (source-part-segmentation).
• Each part has a contour/mask and, if textured, an atlas region (atlas-uv-fitting).
• The object is source-locked in front X/Z before depth is added.
• Canonical view policy is resolved (multiview-constraint-solver) if views conflict.

Workflow

1. Extract source contour from the texture/wireframe region.
2. Extract current mesh boundary in the same projected coordinate space.
3. Build ordered contour correspondence by arc length, named landmarks, or seam/control points.
4. Move boundary vertices to source contour positions.
5. Move interior vertices by smooth interpolation, piecewise-affine warp, or thin-plate-spline style deformation.
6. Preserve UV parameterization by remapping boundary-fitted local coordinates into the atlas rectangle.
7. Re-render overlay; do not proceed to look-dev until texture-region silhouette passes.

Acceptance gates

• Per-part source/product bbox center and size within tolerance.
• Boundary maximum sample error below tolerance after normalization.
• Texture atlas region does not visibly bleed outside the fitted mesh in front view.
• Named landmarks (leaf_tip, base_left, base_right, face_corner, etc.) pass landmark-fit-repair.

Hard rules

• If a texture crop has a different silhouette than the mesh, reshape the mesh first.
• Do not use global UV stretching to hide geometry mismatch.
• Boundary fitting must happen before side-depth/crown deformation.
• Do not tune material/light to compensate for geometry/UV misfit.

Scripts

• scripts/contour_correspondence_report.py reports bbox, centroid, and sampled contour deltas between a source mask and a render/object mask.

Sources distilled

• Piecewise-affine/landmark warping gives a practical mesh deformation model.
• Thin-plate-spline style deformation is appropriate for smooth mascot/logo surfaces when landmarks are sparse.
• Blender mesh vertices/UV layers can be edited directly; BMesh is useful for cleanup after deformation.