Merge branch 'blender-v2.93-release'

1 files changed, 5 insertions, 3 deletions

diff --git a/source/blender/modifiers/intern/MOD_simpledeform.c b/source/blender/modifiers/intern/MOD_simpledeform.c
index 6300db2cb36..db01dec4d19 100644
--- a/source/blender/modifiers/intern/MOD_simpledeform.c
+++ b/source/blender/modifiers/intern/MOD_simpledeform.c
@@ -184,10 +184,12 @@ static void simpleDeform_bend(const float factor,
   sint = sinf(theta);
   cost = cosf(theta);
 
+  /* NOTE: the operations below a susceptible to float precision errors
+   * regarding the order of operations, take care when changing, see: T85470 */
   switch (axis) {
     case 0:
       r_co[0] = x;
-      r_co[1] = (y - 1.0f / factor) * cost + 1.0f / factor;
+      r_co[1] = y * cost + (1.0f - cost) / factor;
       r_co[2] = -(y - 1.0f / factor) * sint;
       {
         r_co[0] += dcut[0];
@@ -196,7 +198,7 @@ static void simpleDeform_bend(const float factor,
       }
       break;
     case 1:
-      r_co[0] = (x - 1.0f / factor) * cost + 1.0f / factor;
+      r_co[0] = x * cost + (1.0f - cost) / factor;
       r_co[1] = y;
       r_co[2] = -(x - 1.0f / factor) * sint;
       {
@@ -207,7 +209,7 @@ static void simpleDeform_bend(const float factor,
       break;
     default:
       r_co[0] = -(y - 1.0f / factor) * sint;
-      r_co[1] = (y - 1.0f / factor) * cost + 1.0f / factor;
+      r_co[1] = y * cost + (1.0f - cost) / factor;
       r_co[2] = z;
       {
         r_co[0] += cost * dcut[0];