This was... horribly wrong, CDDM will often *not* need to allocate
anything to return arrays of mesh items! Just check whether array
pointer is NULL.
Also, remove `DM_get_looptri_array`, that one is useless currently,
`dm->getLoopTriArray` will always return cached array (computing it if
needed).
Title says pretty much everything, we now have BKE and RNA funcs to get vertex, poly and
loop normals of a given shapekey.
This will be used e.g. in FBX exporter (shapekeys need normal data too).
Reviewed By: campbellbarton
Differential Revision: https://developer.blender.org/D1510
Null-area face could generate an int overflow, and potential numerical imprecision in face area computation
could lead to negative number of rays-to-cast (though highly unlikely).
Also, use domnant axis of poly normal as 'flattening' one, instead of always using Z axis.
Points raised by Campbell, thanks!
This allows to match and transfer data between two meshes with similar shape but complete arbitrary different transform.
Note that the result will be best if the meshes (more precisely, their vertices) are exact copies of each other.
Otherwise, method used can only perform an approximated best match, which means you'll likely get better
results if you 'visually' make them match in 3D space (and use 'Object Transform') instead.
In org work, bvhtree helpers were modifying passed co/no in place according to given transform.
However, during review pass we decided this was bad, and made them modify copies. But this broke
some cases where we'd do extra tests after bvhtree query, expecting tmp_co to be in tree (aka source) space!
Further more, since in quite a few cases we were already doing that transform outside of bvhtree helpers,
decided to remove this alltogether from the helpers - makes things more clear and easy to follow,
avoids needless copy of vector, and ensures we are always using tmp_co in its transformed version!
This commit fixes several issues:
* island_store->items_to_islands_num was reset each time we added a new island, this is stupid! Harmless too, though, afaikt.
* partial verts bvhtree (with several islands) was hugely over-allocated...
* we would 'leak' in neighbor islands when geometry itself was contiguous.
* best_nor_dot was used incorrectly, leading to smaller weights for better matching normal!
All those fixes are related to T44522 (through personal communications with reporter).
would fail on coplanar faces (or smooth verts).
Loop remapping is really a tricky topic... For now, we enhance a bit more
our Frankenfunc by using distance between dest and source polygons as
fallback in case we have too much similar normals...
Probably not a perfect solution, but should be robust enough I hope.
One core question remains open though: do we want to stick to 'use only seams
to detect UV islands'? This makes things much simpler, but will obviously fail
in case of actual islands without matching seams. :/
This is the core code for it, tools (datatransfer and modifier) will come in next commits).
RNA api is already there, though.
See the code for details, but basically, we define, for each 'smooth fan'
(which is a set of adjacent loops around a same vertex that are smooth, i.e. have a single same normal),
a 'loop normal space' (or lnor space), using auto-computed normal and relevant edges, and store
custom normal as two angular factors inside that space. This allows to have custom normals
'following' deformations of the geometry, and to only save two shorts per loop in new clnor CDLayer.
Normal manipulation (editing, mixing, interpolating, etc.) shall always happen with plain 3D vectors normals,
and be converted back into storage format at the end.
Clnor computation has also been threaded (at least for Mesh case, not for BMesh), since the process can
be rather heavy with high poly meshes.
Also, bumping subversion, and fix mess in 2.70 versioning code.
Issue was, when requesting (building) lnors for a mesh that has
autosmooth disabled, one would expect to simply get vnors as lnors.
Until now, it wasn't the case, which was bad e.g. for normal projections
of loops in recent remap code (projecting along split loop normals
when you would expect projection along vertex normals...).
Also, removed the 'angle' parameter from RNA's `mesh.calc_normals_split`.
This should *always* use mesh settings (both autosmooth and smoothresh),
otherwise once again we'd get inconsistencies in some cases.
Will update fbx and obj addons too.
This is the (big!) core of mesh transfer data, it defines a set of structures
to represent a mapping of mesh elements (verts, edges, polys of loops) between
two arbitrary meshes, and code to compute such mappings.
No similarity is required between source and destination meshes (though results
when using complete different meshes are rather unlikely to be useful!).
This code is not bound to data transfer, it is defined to be as generic as possible,
and easy to reuse or extend as needs arise.
Several methods of mapping generation are defined for each element type,
we probably will have to adjust that in future (remove useless ones, add
new ones...).
For loops, you can also define islands (for UVs e.g.) so that loops of a same
destination polygon do not 'spread' across several source islands.
Heavily reviewed and enhanced by Campbell, thanks a lot!
