tmaq
/
tornavis
1
0
Fork 0
Code Issues 2 Pull Requests 29 Packages Projects 24 Releases Wiki Activity

Fix for wobbly volume object outlines in the viewport 

The outlines of volume grids in the viewport are noticeable "wobbly"
when they should simply represent grid boxes. This is especially
noticeable on simple regular grids such as the "Volume Cube" geometry
node output.

The reason is that the outlines generated by taking a triangulated mesh
of the grid boxes and then growing it by successively scaling each
triangle. The offset for each vertex grows proportional to its degree
(number of connected edges). The fix is to divide each vertex's offset
by its degree.

The resulting mesh is much more regular and closer to to 1% desired
growth factor.

Old: ![Screenshot_20230829_155602](/attachments/87fbdca3-fb9d-49d8-b4f5-6780d1c72f79)
New: ![Screenshot_20230829_155648](/attachments/4452c52b-96df-4200-a02f-3d0d8aa8680e)

Pull Request: https://projects.blender.org/blender/blender/pulls/111657
This commit is contained in:
Lukas Tönne 2023-10-06 17:43:07 +02:00
parent 87bf783479
commit 711c9c5553
1 changed files with 7 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
source/blender/blenkernel/intern/volume_render.cc
View File

@ -385,14 +385,20 @@ static void grow_triangles(blender::MutableSpan<blender::float3> verts,
/* Compute the offset for every vertex based on the connected edges.
* This formula simply tries increases the length of all edges. */
blender::Array<blender::float3> offsets(verts.size(), {0, 0, 0});
blender::Array<float> weights(verts.size(), 0.0f);
for (const std::array<int, 3> &tri : tris) {
offsets[tri[0]] += factor * (2 * verts[tri[0]] - verts[tri[1]] - verts[tri[2]]);
offsets[tri[1]] += factor * (2 * verts[tri[1]] - verts[tri[0]] - verts[tri[2]]);
offsets[tri[2]] += factor * (2 * verts[tri[2]] - verts[tri[0]] - verts[tri[1]]);
weights[tri[0]] += 1.0;
weights[tri[1]] += 1.0;
weights[tri[2]] += 1.0;
}
/* Apply the computed offsets. */
for (const int i : verts.index_range()) {
verts[i] += offsets[i];
if (weights[i] > 0.0f) {
verts[i] += offsets[i] / weights[i];
}
}
}
#endif /* WITH_OPENVDB */