[#23673] Modifier construction gives correct result in viewport but incorrect in render.

When there are 2+ consecutive deform modifiers, the second modifier was getting incorrect normals, this only showed up for the displace modifier since its the only deform modifier that uses vertex normals.

It would have been easy to fix this by always calculating normals on deform modifiers, but slow.

To fix this I added a function to check if a deform modifier needs normals, so the normal calculation function only runs if there are 2 modifiers in a row and the second uses normals.

1 files changed, 1 insertions, 0 deletions

diff --git a/source/blender/modifiers/intern/MOD_simpledeform.c b/source/blender/modifiers/intern/MOD_simpledeform.c
index c64fec4075d..ab580781351 100644
--- a/source/blender/modifiers/intern/MOD_simpledeform.c
+++ b/source/blender/modifiers/intern/MOD_simpledeform.c
@@ -372,6 +372,7 @@ ModifierTypeInfo modifierType_SimpleDeform = {
 	/* isDisabled */        0,
 	/* updateDepgraph */    updateDepgraph,
 	/* dependsOnTime */     0,
+	/* dependsOnNormals */	0,
 	/* foreachObjectLink */ foreachObjectLink,
 	/* foreachIDLink */     0,
 };