The simple subdivision as a type only causes issues like no-continuous
normals across edges, inability to reliably switch the type and things
like this.
The new subdivision operators supports wider variety of how to add
details to the model, which are more powerful than a single one-time
decision on the subdivision type.
The versioning code is adjusting topology converter to specify all
edges as infinitely sharp. The reason for this (instead of using
settings.is_simple) is because in a longer term the simple subdivision
will be removed from Subsurf modifier as well, and will be replaced
with more efficient bmesh-based modifier.
This is finished up version of D8436.
Differential Revision: https://developer.blender.org/D9350
Propagation when changing sculpt level was missing. In fact, the mask
was simply completely removed when changing sculpt level.
Subdivision worked for simple and linear subdivision, but Catmull-Clark
was giving empty results.
Fixes propagation part of T76386.
This implements the main unsubdivide algorithm which rebuilds a base mesh and extracts the grid's data from a high resolution mesh.
It includes the Rebuild Subdivisions operator, which generates all subdivision levels down to the level 0 base mesh.
It supports:
- Rebuilding an arbitrary number of levels (Unsubdivide) or as many levels as possible down to level 0 in a single step (Rebuild Subdivisions).
- Rebuilding with already existing grids.
- Meshes with n-gons and triangles
- Meshes with more than 2 faces per edge
- Base mesh made completely out of triangles
- Meshes without poles
- Meshes with multiple disconnected elements at the same subdivision level
Reviewed By: sergey
Differential Revision: https://developer.blender.org/D7372
The old Subdivide button was behaving as if subdivision modifier was
applied on top of the multires. This was the source of shrinkage since
the behavior of the limit surface: limit surface of a sparse point
from another limit surface makes final result appear smaller.
The new behavior is based on propagating delta against base mesh's
limit surface to the top level. Effectively, this is as if we've
sculpted on old top level and then propagated to the new top level.
Differential Revision: https://developer.blender.org/D7505
Actually, begin will do the entire initialization.
Refine will only refine if there is a topology refiner associated
with the Subdiv descriptor.
Allows to refine Subdiv to new coarse positions without touching
displacement evaluation. Will be needed to update SubdivCCG during
sculpt undo.
This change fixes artifacts produced by these operations.
On a technical aspect this is done by porting all of the operations
to the new subdivision surface implementation which ensures that
tangent space used to evaluate modifier and those operations is
exactly the same (before modifier will use new code and the operations
will still use an old one).
The next step is to get sculpting on a non-top level to work, and
that actually requires fixes in the undo system.
