New in this release is the Angle Based unwrapping tool, that can handle more complex meshes without the need for manual pinning. The results of LSCM, now renamed to Conformal unwrapping, are also improved. Angle Based unwrapping is intergrated exactly the same way as Conformal, and replaces it by default, with full support for seams, pins and live unwrap. A dropdown menu in the UV Calculation panel allows to choose between Conformal and Angle Based, but the latter will generally give better results. Live unwrapping is also much faster for large meshes.
See the Snurgle being unwrapped in real time:
download.blender.org/demo/movies/seamcut_blender242.mov
Implementation was based on this paper:
A. Sheffer, B. Lévy, M. Mogilnitsky, A, Bogomyakov, ABF++: Fast and Robust Angle Based Flattening, ACM Transactions on Graphics, 24(2), 311-330 2005.
To make the seam cut, unwrap workflow faster, new seam cutting tools have been added to face select mode. Edges can now be marked as seams by a single click on them, or from one edge to another, and seams can be marked around selected faces.
There's a short tutorial on how to use these tools together with Angle Based unwrapping.
This new tool allows to improve the UV coordinates by reducing stretching. Angle Based and Conformal unwrapping strive to preserve shape, but sometimes fail to assign equal amounts of area in the UV map to all parts of the mesh. For example the ears in a head unwrap tend to get only a small part of the image. Minimize Stretch tries to improve this by assigning more area to these regions.
The Minimize Stretch tool can be used as follows. Select some UV's in the UV editor, and then press Ctrl+V. The UV's on the boundary will stay fixed, while the inner UV's get moved. By pressing Numpad +/- or the mouse wheel during this process you can blend between the original and the new UV's, to find a balance between area and shape distortion.
- If one UV is pinned, the others belonging to the same vertex are pinned also.
- Live unwrap is only executed on charts whose pinned UV's change.
- Prevent internal overlaps (e.g. eyes, mouth) for unwrapping.
- Allow the internal boundaries to move freely during stretch minimization.
- The action buttons for mapping were removed from the panel, leaving only settings. All the UV mapping functions are still available from the U key menu in the 3d view, of course.
- Some UV mapping methods have been renamed to indicated more clearly they are view dependent. Standard mapping has been renamed to Reset.
