The Unwrap tool flattens an open 3D mesh into 2D. This can be useful for generating UV coordinates in another program. The tool will attempt to prevent "fold-overs" or self-intersections in the resulting 2D mesh.
NOTE: This tool will only operate on open meshes (i.e. meshes must have a boundary).
- Unwrap Elements
- By component: unwraps each physically connected mesh separately
- By groups: unwraps each face group separately
- Unwrap Type
- Rigid: Attempts to preserve the shape of each triangle (i.e. angles and areas).
- Conformal: Attempts to preserve triangle angles, but not areas. By sacrificing areas, we are sometimes able to do a better job at preserving angles.
- Packing Type: How are are the resulting 2D meshes places in the scene
- Stacked: 2D meshes are all placed at the origin
- Line: meshes are placed in a line
- Optimized: meshes are distributed over the ground plane.
- Pack Settings (only applies to Optimized Packing Type): dimensions of a square on the plane into which the meshes are packed.
The distortion of each triangle is shown as a red heat map on the resulting flat mesh.
By first breaking the model up in to face groups, you can sometimes achieve a better quality result (less distortion). In this example we are unwrapping the bunny model. Note the area of very dense triangles in the result.
Now we carefully select a region of the bunny and create a face group from the region. Running the unwrap tool again, and selecting By Groups in the Unwrap Elements drop-down results in two disconnected meshes, however there is much less distortion in the final result.