Use polygon normals for baking

1 files changed, 11 insertions, 4 deletions

diff --git a/source/blender/render/intern/source/bake_api.c b/source/blender/render/intern/source/bake_api.c
index 5e982e84f6d..636c4db6ef3 100644
--- a/source/blender/render/intern/source/bake_api.c
+++ b/source/blender/render/intern/source/bake_api.c
@@ -64,6 +64,8 @@
  * For a complete implementation example look at the Cycles Bake commit.
  */
 
+#include <limits.h>
+
 #include "MEM_guardedalloc.h"
 
 #include "BLI_math.h"
@@ -364,6 +366,9 @@ static void mesh_calc_tri_tessface(
 	bool calculate_normal;
 	const int tottri = poly_to_tri_count(me->totpoly, me->totloop);
 	MLoopTri *looptri;
+	/* calculate normal for each polygon only once */
+	unsigned int mpoly_prev = UINT_MAX;
+	float no[3];
 
 	mvert = CustomData_get_layer(&me->vdata, CD_MVERT);
 	looptri = MEM_mallocN(sizeof(*looptri) * tottri, __func__);
@@ -400,10 +405,12 @@ static void mesh_calc_tri_tessface(
 			triangles[i].tspace[2] = &tspace[lt->tri[2]];
 
 			if (calculate_normal) {
-				normal_tri_v3(triangles[i].normal,
-				              triangles[i].mverts[0]->co,
-				              triangles[i].mverts[1]->co,
-				              triangles[i].mverts[2]->co);
+				if (lt->poly != mpoly_prev) {
+					const MPoly *mp = &me->mpoly[lt->poly];
+					BKE_mesh_calc_poly_normal(mp, &me->mloop[mp->loopstart], me->mvert, no);
+					mpoly_prev = lt->poly;
+				}
+				copy_v3_v3(triangles[i].normal, no);
 			}
 			else {
 				copy_v3_v3(triangles[i].normal, &precomputed_normals[lt->poly]);