Fix T101669: Cycles artifacts in bump map baking

After barycentric convention changes, the differentials used for bump mapping
were wrong leading to artifacts with long thin triangles.

1 files changed, 7 insertions, 0 deletions

diff --git a/intern/cycles/kernel/integrator/init_from_bake.h b/intern/cycles/kernel/integrator/init_from_bake.h
index 667ba949760..cc3fbe3fe39 100644
--- a/intern/cycles/kernel/integrator/init_from_bake.h
+++ b/intern/cycles/kernel/integrator/init_from_bake.h
@@ -156,6 +156,13 @@ ccl_device bool integrator_init_from_bake(KernelGlobals kg,
   u = v;
   v = 1.0f - tmp - v;
 
+  const float tmpdx = dudx;
+  const float tmpdy = dudy;
+  dudx = dvdx;
+  dudy = dvdy;
+  dvdx = -tmpdx - dvdx;
+  dvdy = -tmpdy - dvdy;
+
   /* Position and normal on triangle. */
   const int object = kernel_data.bake.object_index;
   float3 P, Ng;