Better fix than rBbef5cb3aa2e5a: consider edges between faces with opposed normals as sharp.
In fact, previous code was broken more deeply in this case (inconsistent normals across
a 'smooth fan') - some loop normals would even never be computed!
Fixing this is possible (even wrote it, actually), but this adds more complexity
to a piece of code that is already awfully complicated, *and* normals in that kind
of smooth fan do not make much sense anyway. So simpler and nicer results with
assuming sharp edges between such 'opposed' faces!
Note that there is some face (loop) ordering black magic at work here, added more comments
to try to explain how and why all this works.
As a bonus, we do not need to check for already computed loop normals anymore, since we
know each 'smooth fan' will be walked once, and only once.
This crash can only happen in case faces in same 'smooth fan' have reversed normals.
To support this, we have to always keep a way to get real values in loop_to_poly,
even when loop itself is tagged as done, it might be needed in computation of one of
its neighbor's split normal later.
Tessellated split normals CDlayer had no swap func, hence ugly little test_index_face()
could not rotate its values correctly when rotating tessellated faces...
Extra-reported in T39735.
* Add a new calcLoopNormals function to DerivedMesh struct, and implement it for CDDM and CCGDM (subsurf).
EditDerivedBMesh (edit mode DM) only gets a dummy one in this commit.
* Add a tessellated version of CD_LOOPNORMAL layer (CD_TESSLOOPNORMAL), with relevant code to handle it
(tessellation, rna access, etc.).
* Change auto_smooth options of Mesh (angle now in radian internaly, and toggle is now used to enable/disable
split normals in DM creation process). Note BI render code is not touched here, hence its behavior regarding
this option is now incoherent, will be addressed in a separate commit.
Reviewers: campbellbarton
CC: brecht
Differential Revision: https://developer.blender.org/D365
Own bug from rBc691551249f3. Now at least I understand why `test_index_face()` is needed for tessellated quads!
Added a bunch of comments to explain the issue, as it's far from an obvious one...
We loose some performances, but it's still much quicker than org code.
The main idea is to store (during tessellation) or recreate (during tessdata update) a tessfaceverts-to-loops mapping, and then update all tessdata
in one pass, instead of calling `BKE_mesh_loops_to_mface_corners` repeatedly for all tfaces!
Differential Revision: https://developer.blender.org/D226
Reviewed by Campbell, thanks a lot!
This simply mimics code used for loopnormals, to enable py scripts to generate and access (temporary)
a tangent 3D vector and bitangent sign for each loop. Together with the split normals, this allow
to recreate a complete tangent space for normal mapping (bitangent = bitangent_sign * cross(normal, tangent)).
Expects all faces to be tri or quads.
Reviewed By: Brecht, campbellbarton
Differential Revision: https://developer.blender.org/D185
since enough bmesh operations can also take advantage of direct index lookups on verts/edges/faces.
developers note:
- EDBM_index_arrays_init/ensure/free -> BM_mesh_elem_table_ensure/init/free
- EDBM_vert/edge/face_at_index -> BM_vert/edge/face_at_index
- EDBM_uv_element_map_create/free -> BM_uv_element_map_create/free
- ED_uv_element_get -> BM_uv_element_get
Was a silly error introduced in algo during optimization, vertices having sharp and smooth edges would only get the first poly's normal for each "smooth loop group".
Also done a (minor) optimization, and some comment fixes.
- make cmake osx use of -ftemplate-depth match scons.
- use array size within sizeof(), more compact.
- replace AT with __func__ where the function is unique enough.
- BLI_box_pack_2D -> 2d to match other functions.
- rename new mesh normal calculation to mesh.calc_normals_split()
