UDIM: Support tile sets that do not start at 1001

Removes the artificial requirement that UDIM tile sets start at 1001.
Blender was already capable of handling sparse tile sets (non-contiguous
tiles) so the restriction around starting at 1001 was unnecessary in
general.

This required fixing a few UDIM-related python bugs around manually
updating the `tile_number` field on images as well. See the differential
for details. No script changes are necessary but they will now work,
correctly, in many more cases.

Differential Revision: https://developer.blender.org/D11859

1 files changed, 2 insertions, 7 deletions

diff --git a/source/blender/makesrna/intern/rna_image.c b/source/blender/makesrna/intern/rna_image.c
index c058ab6cfcc..e44ddb07d53 100644
--- a/source/blender/makesrna/intern/rna_image.c
+++ b/source/blender/makesrna/intern/rna_image.c
@@ -290,15 +290,10 @@ static void rna_UDIMTile_tile_number_set(PointerRNA *ptr, int value)
   ImageTile *tile = (ImageTile *)ptr->data;
   Image *image = (Image *)ptr->owner_id;
 
-  /* The index of the first tile can't be changed. */
-  if (tile->tile_number == 1001) {
-    return;
-  }
-
   /* Check that no other tile already has that number. */
   ImageTile *cur_tile = BKE_image_get_tile(image, value);
-  if (cur_tile == NULL || cur_tile == tile) {
-    tile->tile_number = value;
+  if (cur_tile == NULL) {
+    BKE_image_reassign_tile(image, tile, value);
   }
 }