Cycles: Fix one-tile UDIM rendering

The code checked for the presence of more than one tile before
substituting the tile number into the filename, so if a one-tile
UDIM was used (or all but one tile were culled), the substitution
was skipped and as a result the file was not found.

With this change, the code explicitly tracks whether substitution
is required, avoiding this problem.

This also fixes another problem: The Environment texture never
does substitution since it doesn't support UDIMs, but before the
syncing code still inserted the placeholder into the filename if the
user selected a tiled background image.

1 files changed, 3 insertions, 2 deletions

diff --git a/intern/cycles/blender/blender_shader.cpp b/intern/cycles/blender/blender_shader.cpp
index 6bbc73f72ec..215953d1f29 100644
--- a/intern/cycles/blender/blender_shader.cpp
+++ b/intern/cycles/blender/blender_shader.cpp
@@ -655,7 +655,8 @@ static ShaderNode *add_node(Scene *scene,
         image->builtin_data = b_image.ptr.data;
       }
       else {
-        image->filename = image_user_file_path(b_image_user, b_image, b_scene.frame_current());
+        image->filename = image_user_file_path(
+            b_image_user, b_image, b_scene.frame_current(), &image->is_tiled);
         image->builtin_data = NULL;
       }
 
@@ -709,7 +710,7 @@ static ShaderNode *add_node(Scene *scene,
         env->builtin_data = b_image.ptr.data;
       }
       else {
-        env->filename = image_user_file_path(b_image_user, b_image, b_scene.frame_current());
+        env->filename = image_user_file_path(b_image_user, b_image, b_scene.frame_current(), NULL);
         env->builtin_data = NULL;
       }