Fix for [#26133] Explode modifier doesn't care about UVs (Option "split edges")

* This is basically a total rewrite of the edge split algorithm. The old one didn't handle tris at all and quads were cut wrong in some cases too with the addition of not handling uv coordinates at all.
* This new algorithm uses a flag system to categorize different splits and the identical but rotated cases in a similar way to how marching cubes indexes different cases.
* It cuts quads and tris and creates proper uv's for the new faces too.
* I also renamed the option to "edge cut" to differentiate if from the edge split modifier and added an option to override a uv-channel in the exploded mesh with particle age as x-coordinate so that the shrapnel can be faded out nicely etc.

1 files changed, 2 insertions, 1 deletions

diff --git a/source/blender/makesdna/DNA_modifier_types.h b/source/blender/makesdna/DNA_modifier_types.h
index 687a05f7afb..28840d55efc 100644
--- a/source/blender/makesdna/DNA_modifier_types.h
+++ b/source/blender/makesdna/DNA_modifier_types.h
@@ -588,7 +588,7 @@ typedef struct ParticleInstanceModifierData {
 typedef enum {
 	eExplodeFlag_CalcFaces =	(1<<0),
 	eExplodeFlag_PaSize =		(1<<1),
-	eExplodeFlag_EdgeSplit =	(1<<2),
+	eExplodeFlag_EdgeCut =		(1<<2),
 	eExplodeFlag_Unborn =		(1<<3),
 	eExplodeFlag_Alive =		(1<<4),
 	eExplodeFlag_Dead =			(1<<5),
@@ -599,6 +599,7 @@ typedef struct ExplodeModifierData {
 	int *facepa;
 	short flag, vgroup;
 	float protect;
+	char uvname[32];
 } ExplodeModifierData;
 
 typedef struct MultiresModifierData {