Workbench: Fix shadow artifact caused by degenerate triangles

Fixes T58735 Incorrect workbench shadow from n-gons

This also optimize the degenerate triangle detection by searching if
their area is near 0.0.
This commit is contained in:
Clément Foucault 2018-12-11 01:23:32 +01:00
parent a49fdbcc67
commit 3dfbb72b29
Notes: blender-bot 2023-02-14 11:00:17 +01:00
Referenced by issue #59121, Weird Shadows on viewport (solid mode)
Referenced by issue #58735, Incorrect workbench shadow from n-gons
1 changed files with 12 additions and 13 deletions

View File

@ -55,20 +55,19 @@ void main()
vec3 v12 = vData[2].pos - vData[1].pos;
vec3 v13 = vData[3].pos - vData[1].pos;
#ifdef DEGENERATE_THRESHOLD
vec3 v20 = vData[0].pos - vData[2].pos;
vec3 v23 = vData[3].pos - vData[2].pos;
vec3 n1 = cross(v12, v10);
vec3 n2 = cross(v13, v12);
vec4 edges_lensqr = vec4(len_sqr(v10), len_sqr(v13), len_sqr(v20), len_sqr(v23));
bvec4 degen_edges = lessThan(edges_lensqr, vec4(DEGENERATE_THRESHOLD));
#ifdef DEGENERATE_THRESHOLD
/* Check if area is null */
vec2 faces_area = vec2(len_sqr(n1), len_sqr(n2));
bvec2 degen_faces = lessThan(abs(faces_area), vec2(DEGENERATE_THRESHOLD));
/* Both triangles are degenerate, abort. */
if (any(degen_edges.xz) && any(degen_edges.yw))
if (all(degen_faces))
return;
#endif
vec3 n1 = cross(v12, v10);
vec3 n2 = cross(v13, v12);
vec2 facing = vec2(dot(n1, lightDirection),
dot(n2, lightDirection));
@ -81,15 +80,15 @@ void main()
# ifndef DOUBLE_MANIFOLD
/* If the mesh is known to be manifold and we don't use double count,
* only create an quad if the we encounter a facing geom. */
if ((any(degen_edges.xz) && backface.y) ||
(any(degen_edges.yw) && backface.x))
if ((degen_faces.x && backface.y) ||
(degen_faces.y && backface.x))
return;
# endif
/* If one of the 2 triangles is degenerate, replace edge by a non-manifold one. */
backface.x = (any(degen_edges.xz)) ? !backface.y : backface.x;
backface.y = (any(degen_edges.yw)) ? !backface.x : backface.y;
is_manifold = (any(degen_edges)) ? false : is_manifold;
backface.x = (degen_faces.x) ? !backface.y : backface.x;
backface.y = (degen_faces.y) ? !backface.x : backface.y;
is_manifold = (any(degen_faces)) ? false : is_manifold;
#endif
/* If both faces face the same direction it's not an outline edge. */