There were some issues with PBVH which prevented working it for meshes without faces.
Discussed with Brecht, for benefits of dynamic-topology-sculpting and so better to
make PBVH survive such things.
Added some extra NULL-pointer checks for this.
OK, after that failure of committing a bunch of old junk, hopefully
this is what I actually meant to commit :)
* Added big comments to some of the fields in struct PBVHNode. I
always forget the details of these, so finally wrote it down
properly.
* Changed types of PBVHNode.face_vert_indices and PBVHNode.flag to
better reflect their contents.
* There should be no functional changes here.
Used a crazyspace approach (like in edit mode), but only modifiers with
deformMatricies are allowed atm (currently shapekeys and armature modifiers only).
All the rest modifiers had an warning message that they aren't applied because
of sculpt mode. Deformation of multires is also unsupported.
With all this restictions users will always see the actual "layer" (or maybe
mesh state would be more correct word) they are sculpting on.
Internal changes:
- All modifiers could have deformMatricies callback (the same as deformMatriciesEM but
for non-edit mode usage)
- Added function to build crazyspace for sculpting (sculpt_get_deform_matrices), but it
could be generalized for usage in other painting modes (particle edit mode, i.e)
Todo:
- Implement crazyspace correction to support all kinds of deformation modifiers
- Maybe deformation of multires isn't so difficult?
- And maybe we could avoid extra bad-level-stub for ED_sculpt_modifiers_changed
without code duplicating?
- made interface, windowmanager, readfile build without unused warnings.
- re-arranged CMake's source/blender build order so less changed libs are build later, eg: IK, avi
PBVH used the same verts array as mesh data and shape key/reference key coords
were applying on the mesh data, so on some refreshing undeformed mesh was
displayed.
Added utility functions to get vert coords from key block, apply new vert coords
on keyblock and function to apply coords on bpvh, so now pbvh uses it's ovn
vertex array and no changes are making to the mesh data.
Additional change:
Store key block name in SculptUndoNode, so now shape wouldn't be copied to
wrong keyblock on undo
Fixes various crashes and redraw problems, most noticeable new feature
is that you can now sculpt on a multires mesh with deforming modifiers
preceding it.
I've left out support for sculpting on multires with enabled modifiers
following it, in this case only the base mesh can be sculpted now. The
code changes needed to do this are just too ugly in my opinion, would
need a more torough redesign which I don't think we should try now. In
my opinion this is also not really an important case, since it's going
to be incredibly slow anyway to run a modifier on a high res mesh while
sculpting.
So, to summarize current state:
* Fastest sculpting: base mesh with no modifiers or multires with only
modifiers preceding it.
* Slower sculpting: base mesh with modifiers, depends on the speed of
the modifiers.
* Not supported: multires mesh with modifiers following it.
were cached once at the start, but these can change when modifiers are
executed, now it simply doesn't cache them anymore, that was only really
a performance bottleneck when it was caching individual vertices.
* Increase epsilon for intersection a bit more, ortho view + small
faces are problematic.
* Fix a redraw issue with one partial redraw too much at the end of
the stroke.
* Temporary workaround for sculpt not working well with small polygons,
still seems to be some issues, but can at least paint now.
* Small optimization avoiding local function variable aliasing.
* Added detection if VBO extension is supported.
* Redraw other 3d views after sculpting.
* Fix brush sometimes punching through mesh with very small polygons,
added an extra epsilon to the ray-triangle intersection.
* Don't allow adding/removing multires levels in editmode.
* Customdata code for swapping mdisps restored.
* Fix inflate brush crashing with multires.
* Smooth and layer brush don't work yet with multires, but at
least avoids crashing now.
* Fix threading issue with flatten brush.
* PBVH can now be created contain both from face grids or standard
meshes. The former is much quicker to build for high res meshes.
* Moved some drawing code into pbvh (mostly for the frustum test).
* Moved ray intersection code into pbvh.
* GPU buffers also can be built from either mesh or grids now.
* Updated sculpt code to work with this. The ugly part is that there
is now a macro for iterating over vertices, to handle both cases,
and some duplicated code for e.g. undo.
* Smooth brush does not work yet with grids.
* Draw/Inflate/Layer now keep working on the original mesh coordinates and
normals from when the stroke started. This helps avoid the mesh blowing
up, but can still be better. The old behavior is still available as
"Accumulate" in the UI.
* This requires some more memory usage for the BVH, would like to find a
way to avoid that.
* Smooth falloff is now the default.
* Spacing is now enabled by default, with a value of 7.5.
* Anchored now stores normals per node to save some memory.
The weak point now is the thread-safe atomic access to normals from multiple
threads, did not seem to be a bottleneck in my tests but I don't really trust
it to be fast.
* Sculpting, normal update and bounding box code is now multithreaded
using OpenMP.
* Fix a number of update issues: normals on node boundaries, outdated
bounding boxes, partial redraw, .. . There's probably still a few
left, but should be better now.
* Clicking once now does a single paint instead of two (was also
painting on mouse up event).
* Smooth shading now is enabled for the full mesh when the first face
uses it (so it can be tested at least).
Implementation Notes:
* PBVH search can now be done either using a callback or bt gathering the
nodes in an array. The latter makes multithreading with OpenMP easier.
* Normals update code is now inside PBVH, was doing it per node before but
should do all faces first and only then vertices.
* Instead of using search modes + 1 modified flag, now nodes get 4 flags
to indicate what needs to be updated for them, found that this makes it
easier for me to understand the code and fix update bugs.
* PBVHNode is now exposed as an abstract type, I think this makes it more
clear what is happening than having it's data passed as part of callback
functions.
* Active_verts list was replaced by looping over nodes and the vertices
inside them. However the grab brush still uses the active_verts system,
will fix that later.
* Some micro-optimizations, like avoiding a few multiplications/divisions,
using local variables instead of pointers, or looping over fewer vertices
to update the bounding boxes.
