fix [#32646] Duplifaces can have wrong orientation with ngons

concave ngons could flip the dupliface, now use the faces normal when calculating the dupli-face.

7 files changed, 32 insertions, 19 deletions

diff --git a/source/blender/blenkernel/BKE_mesh.h b/source/blender/blenkernel/BKE_mesh.h
index 954fb47806b..0b082c46471 100644
--- a/source/blender/blenkernel/BKE_mesh.h
+++ b/source/blender/blenkernel/BKE_mesh.h
@@ -88,8 +88,8 @@ int BKE_mesh_mpoly_to_mface(struct CustomData *fdata, struct CustomData *ldata,
                             struct CustomData *pdata, int totface, int totloop, int totpoly);
 
 /*calculates a face normal.*/
-void mesh_calc_poly_normal(struct MPoly *mpoly, struct MLoop *loopstart, 
-                           struct MVert *mvarray, float no[3]);
+void BKE_mesh_calc_poly_normal(struct MPoly *mpoly, struct MLoop *loopstart,
+                               struct MVert *mvarray, float no[3]);
 
 void BKE_mesh_calc_poly_normal_coords(struct MPoly *mpoly, struct MLoop *loopstart,
                                       const float (*vertex_coords)[3], float no[3]);
diff --git a/source/blender/blenkernel/intern/anim.c b/source/blender/blenkernel/intern/anim.c
index 1b301ba43b3..8dbffc5628b 100644
--- a/source/blender/blenkernel/intern/anim.c
+++ b/source/blender/blenkernel/intern/anim.c
@@ -1140,21 +1140,17 @@ static void face_duplilist(ListBase *lb, ID *id, Scene *scene, Object *par, floa
 						float *v3;
 						/* float *v4; */ /* UNUSED */
 						float cent[3], quat[4], mat[3][3], mat3[3][3], tmat[4][4], obmat[4][4];
+						float f_no[3];
 						MLoop *loopstart = mloop + mp->loopstart;
 
-						if (mp->totloop < 3) {
-							/* highly unlikely but to be safe */
+						if (UNLIKELY(mp->totloop < 3)) {
 							continue;
 						}
 						else {
+							BKE_mesh_calc_poly_normal(mp, mloop + mp->loopstart, mvert, f_no);
 							v1 = mvert[(mv1 = loopstart[0].v)].co;
 							v2 = mvert[(mv2 = loopstart[1].v)].co;
 							v3 = mvert[(mv3 = loopstart[2].v)].co;
-#if 0
-							if (mp->totloop > 3) {
-								v4 = mvert[(mv4 = loopstart[3].v)].co;
-							}
-#endif
 						}
 
 						/* translation */
@@ -1170,7 +1166,7 @@ static void face_duplilist(ListBase *lb, ID *id, Scene *scene, Object *par, floa
 						copy_v3_v3(obmat[3], cent);
 						
 						/* rotation */
-						tri_to_quat(quat, v1, v2, v3);
+						tri_to_quat_ex(quat, v1, v2, v3, f_no);
 						quat_to_mat3(mat, quat);
 						
 						/* scale */
diff --git a/source/blender/blenkernel/intern/mesh.c b/source/blender/blenkernel/intern/mesh.c
index 206d80a6ff0..f0354b892b7 100644
--- a/source/blender/blenkernel/intern/mesh.c
+++ b/source/blender/blenkernel/intern/mesh.c
@@ -1864,7 +1864,7 @@ void BKE_mesh_calc_normals_mapping_ex(MVert *mverts, int numVerts,
 		/* only calc poly normals */
 		mp = mpolys;
 		for (i = 0; i < numPolys; i++, mp++) {
-			mesh_calc_poly_normal(mp, mloop + mp->loopstart, mverts, pnors[i]);
+			BKE_mesh_calc_poly_normal(mp, mloop + mp->loopstart, mverts, pnors[i]);
 		}
 	}
 
@@ -1914,7 +1914,7 @@ void BKE_mesh_calc_normals(MVert *mverts, int numVerts, MLoop *mloop, MPoly *mpo
 
 	mp = mpolys;
 	for (i = 0; i < numPolys; i++, mp++) {
-		mesh_calc_poly_normal(mp, mloop + mp->loopstart, mverts, pnors[i]);
+		BKE_mesh_calc_poly_normal(mp, mloop + mp->loopstart, mverts, pnors[i]);
 		ml = mloop + mp->loopstart;
 
 		BLI_array_empty(vertcos);
@@ -2900,8 +2900,8 @@ static void mesh_calc_ngon_normal(MPoly *mpoly, MLoop *loopstart,
 	}
 }
 
-void mesh_calc_poly_normal(MPoly *mpoly, MLoop *loopstart, 
-                           MVert *mvarray, float no[3])
+void BKE_mesh_calc_poly_normal(MPoly *mpoly, MLoop *loopstart,
+                               MVert *mvarray, float no[3])
 {
 	if (mpoly->totloop > 4) {
 		mesh_calc_ngon_normal(mpoly, loopstart, mvarray, no);
@@ -3045,7 +3045,7 @@ float BKE_mesh_calc_poly_area(MPoly *mpoly, MLoop *loopstart,
 
 		/* need normal for area_poly_v3 as well */
 		if (polynormal == NULL) {
-			mesh_calc_poly_normal(mpoly, loopstart, mvarray, no);
+			BKE_mesh_calc_poly_normal(mpoly, loopstart, mvarray, no);
 		}
 
 		/* finally calculate the area */
diff --git a/source/blender/blenlib/BLI_math_rotation.h b/source/blender/blenlib/BLI_math_rotation.h
index 8a439c7cf7a..8260331b808 100644
--- a/source/blender/blenlib/BLI_math_rotation.h
+++ b/source/blender/blenlib/BLI_math_rotation.h
@@ -78,6 +78,8 @@ void quat_to_mat4(float mat[4][4], const float q[4]);
 
 void mat3_to_quat(float q[4], float mat[3][3]);
 void mat4_to_quat(float q[4], float mat[4][4]);
+void tri_to_quat_ex(float quat[4], const float v1[3], const float v2[3], const float v3[3],
+                    const float no_orig[3]);
 void tri_to_quat(float q[4], const float a[3], const float b[3], const float c[3]);
 void vec_to_quat(float q[4], const float vec[3], short axis, const short upflag);
 /* note: v1 and v2 must be normalized */
diff --git a/source/blender/blenlib/intern/math_rotation.c b/source/blender/blenlib/intern/math_rotation.c
index e10b0b3298c..1392e88c168 100644
--- a/source/blender/blenlib/intern/math_rotation.c
+++ b/source/blender/blenlib/intern/math_rotation.c
@@ -613,13 +613,21 @@ void add_qt_qtqt(float result[4], const float quat1[4], const float quat2[4], co
 	result[3] = quat1[3] + t * quat2[3];
 }
 
-void tri_to_quat(float quat[4], const float v1[3], const float v2[3], const float v3[3])
+/* same as tri_to_quat() but takes pre-computed normal from the triangle
+ * used for ngons when we know their normal */
+void tri_to_quat_ex(float quat[4], const float v1[3], const float v2[3], const float v3[3],
+                    const float no_orig[3])
 {
 	/* imaginary x-axis, y-axis triangle is being rotated */
 	float vec[3], q1[4], q2[4], n[3], si, co, angle, mat[3][3], imat[3][3];
 
 	/* move z-axis to face-normal */
+#if 0
 	normal_tri_v3(vec, v1, v2, v3);
+#else
+	copy_v3_v3(vec, no_orig);
+	(void)v3;
+#endif
 
 	n[0] =  vec[1];
 	n[1] = -vec[0];
@@ -659,6 +667,13 @@ void tri_to_quat(float quat[4], const float v1[3], const float v2[3], const floa
 	mul_qt_qtqt(quat, q1, q2);
 }
 
+void tri_to_quat(float quat[4], const float v1[3], const float v2[3], const float v3[3])
+{
+	float vec[3];
+	normal_tri_v3(vec, v1, v2, v3);
+	tri_to_quat_ex(quat, v1, v2, v3, vec);
+}
+
 void print_qt(const char *str, const float q[4])
 {
 	printf("%s: %.3f %.3f %.3f %.3f\n", str, q[0], q[1], q[2], q[3]);
diff --git a/source/blender/makesrna/intern/rna_mesh.c b/source/blender/makesrna/intern/rna_mesh.c
index a2212eab729..59cf202a416 100644
--- a/source/blender/makesrna/intern/rna_mesh.c
+++ b/source/blender/makesrna/intern/rna_mesh.c
@@ -224,7 +224,7 @@ static void rna_MeshPolygon_normal_get(PointerRNA *ptr, float *values)
 	MPoly *mp = (MPoly *)ptr->data;
 
 	/* BMESH_TODO: might be faster to look for a CD_NORMALS layer and use that */
-	mesh_calc_poly_normal(mp, me->mloop + mp->loopstart, me->mvert, values);
+	BKE_mesh_calc_poly_normal(mp, me->mloop + mp->loopstart, me->mvert, values);
 }
 
 static float rna_MeshPolygon_area_get(PointerRNA *ptr)
diff --git a/source/blender/modifiers/intern/MOD_solidify.c b/source/blender/modifiers/intern/MOD_solidify.c
index fc74b446762..035dda0c95c 100644
--- a/source/blender/modifiers/intern/MOD_solidify.c
+++ b/source/blender/modifiers/intern/MOD_solidify.c
@@ -107,7 +107,7 @@ static void dm_calc_normal(DerivedMesh *dm, float (*temp_nors)[3])
 
 			f_no = face_nors[i];
 			if (calc_face_nors)
-				mesh_calc_poly_normal(mp, mloop + mp->loopstart, mvert, f_no);
+				BKE_mesh_calc_poly_normal(mp, mloop + mp->loopstart, mvert, f_no);
 
 			ml = mloop + mp->loopstart;
 
@@ -483,7 +483,7 @@ static DerivedMesh *applyModifier(ModifierData *md, Object *ob,
 
 			/* --- not related to angle calc --- */
 			if (face_nors_calc)
-				mesh_calc_poly_normal(mp, ml, mvert, face_nors[i]);
+				BKE_mesh_calc_poly_normal(mp, ml, mvert, face_nors[i]);
 			/* --- end non-angle-calc section --- */
 
 			sub_v3_v3v3(nor_prev, mvert[ml[i_this - 1].v].co, mvert[ml[i_this].v].co);