archive/blender-archive
Archived
1
1
Fork 0
Code Pull Requests Activity

Fix T89249: incorrect mesh validate error with zeroed vertex normals

Browse Source 
It's not an error for centered vertices to have a zero normal.
This commit is contained in:
Campbell Barton
2021-06-23 13:48:33 +10:00
parent 5cc8e7ab53
commit 61b22d27c8
1 changed files with 25 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
source/blender/blenkernel/intern/mesh_validate.c
View File

@@ -217,6 +217,16 @@ static int search_polyloop_cmp(const void *v1, const void *v2)
* Validate the mesh, \a do_fixes requires \a mesh to be non-null.
*
* \return false if no changes needed to be made.
*
* Vertex Normals
* ==============
*
* While zeroed normals are checked, these checks aren't comprehensive.
* Technically, to detect errors here a normal recalculation and comparison is necessary.
* However this function is mainly to prevent severe errors in geometry
* (invalid data that will crash Blender, or cause some features to behave incorrectly),
* not to detect subtle differences in the resulting normals which could be caused
* by importers that load normals (for example).
*/
/* NOLINTNEXTLINE: readability-function-size */
bool BKE_mesh_validate_arrays(Mesh *mesh,
@@ -328,10 +338,21 @@ bool BKE_mesh_validate_arrays(Mesh *mesh,
}
if (fix_normal) {
PRINT_ERR("\tVertex %u: has zero normal, assuming Z-up normal", i);
if (do_fixes) {
mv->no[2] = SHRT_MAX;
fix_flag.verts = true;
/* If the vertex normal accumulates to zero or isn't part of a face, the location is used.
* When the location is also zero, a zero normal warning should not be raised.
* since this is the expected behavior of normal calculation.
*
* This avoids false positives but isn't foolproof as it's possible the vertex
* is part of a polygon that has a normal which this vertex should be using,
* although it's also possible degenerate/opposite faces accumulate to a zero vector.
* To detect this a full normal recalculation would be needed, which is out of scope
* for a basic validity check (see "Vertex Normal" in the doc-string). */
if (!is_zero_v3(mv->co)) {
PRINT_ERR("\tVertex %u: has zero normal, assuming Z-up normal", i);
if (do_fixes) {
mv->no[2] = SHRT_MAX;
fix_flag.verts = true;
}
}
}
}