Fix #24834: curves extrude + bevel gave bad normals on rendering.

This happened when removing vertex normal flipping in the render engine. But
actually the normal of the first face in the curve was flipped on rendering,
because it used a different vertex order than other places. Also removed the
hack that computes a face normal only from a triangle instead of a quad.

1 files changed, 9 insertions, 42 deletions

diff --git a/source/blender/render/intern/source/convertblender.c b/source/blender/render/intern/source/convertblender.c
index fa7532784e2..76befcaeb12 100644
--- a/source/blender/render/intern/source/convertblender.c
+++ b/source/blender/render/intern/source/convertblender.c
@@ -2786,7 +2786,7 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 	float len, *data, *fp, *orco=NULL, *orcobase= NULL;
 	float n[3], mat[4][4];
 	int nr, startvert, startvlak, a, b;
-	int frontside, need_orco=0, totmat;
+	int need_orco=0, totmat;
 
 	cu= ob->data;
 	if(ob->type==OB_FONT && cu->str==NULL) return;
@@ -2844,15 +2844,7 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 					ver= RE_findOrAddVert(obr, obr->totvert++);
 					VECCOPY(ver->co, data);
 
-					/* flip normal if face is backfacing, also used in face loop below */
-					if(ver->co[2] < 0.0) {
-						VECCOPY(ver->n, n);
-						ver->flag = 1;
-					}
-					else {
-						ver->n[0]= -n[0]; ver->n[1]= -n[1]; ver->n[2]= -n[2];
-						ver->flag = 0;
-					}
+					negate_v3_v3(ver->n, n);
 
 					mul_m4_v3(mat, ver->co);
 
@@ -2873,12 +2865,7 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 						vlr->v3= RE_findOrAddVert(obr, startvert+index[2]);
 						vlr->v4= NULL;
 
-						if(vlr->v1->flag) {
-							VECCOPY(vlr->n, n);
-						}
-						else {
-							vlr->n[0]= -n[0]; vlr->n[1]= -n[1]; vlr->n[2]= -n[2];
-						}
+						negate_v3_v3(vlr->n, n);
 
 						vlr->mat= matar[ dl->col ];
 						vlr->flag= 0;
@@ -2917,8 +2904,6 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 
 						for(a=0; a<dl->parts; a++) {
 
-							frontside= (a >= dl->nr/2);
-
 							if (surfindex_displist(dl, a, &b, &p1, &p2, &p3, &p4)==0)
 								break;
 
@@ -2929,25 +2914,16 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 
 							for(; b<dl->nr; b++) {
 								vlr= RE_findOrAddVlak(obr, obr->totvlak++);
-								vlr->v1= RE_findOrAddVert(obr, p2);
-								vlr->v2= RE_findOrAddVert(obr, p1);
-								vlr->v3= RE_findOrAddVert(obr, p3);
-								vlr->v4= RE_findOrAddVert(obr, p4);
-								vlr->ec= ME_V2V3+ME_V3V4;
+								vlr->v1= RE_findOrAddVert(obr, p1);
+								vlr->v2= RE_findOrAddVert(obr, p2);
+								vlr->v3= RE_findOrAddVert(obr, p4);
+								vlr->v4= RE_findOrAddVert(obr, p3);
+								vlr->ec= ME_V4V1+ME_V3V4;
 								if(a==0) vlr->ec+= ME_V1V2;
 
 								vlr->flag= dl->rt;
 
-								/* this is not really scientific: the vertices
-									* 2, 3 en 4 seem to give better vertexnormals than 1 2 3:
-									* front and backside treated different!!
-									*/
-
-								if(frontside)
-									normal_tri_v3( vlr->n,vlr->v4->co, vlr->v3->co, vlr->v2->co);
-								else
-									normal_tri_v3( vlr->n,vlr->v1->co, vlr->v2->co, vlr->v3->co);
-
+								normal_quad_v3(vlr->n, vlr->v4->co, vlr->v3->co, vlr->v2->co, vlr->v1->co);
 								vlr->mat= matar[ dl->col ];
 
 								p4= p3;
@@ -2975,15 +2951,6 @@ static void init_render_curve(Render *re, ObjectRen *obr, int timeoffset)
 						for(a=startvert; a<obr->totvert; a++) {
 							ver= RE_findOrAddVert(obr, a);
 							len= normalize_v3(ver->n);
-							if(len==0.0) ver->flag= 1;	/* flag abuse, its only used in zbuf now  */
-							else ver->flag= 0;
-						}
-						for(a= startvlak; a<obr->totvlak; a++) {
-							vlr= RE_findOrAddVlak(obr, a);
-							if(vlr->v1->flag) VECCOPY(vlr->v1->n, vlr->n);
-							if(vlr->v2->flag) VECCOPY(vlr->v2->n, vlr->n);
-							if(vlr->v3->flag) VECCOPY(vlr->v3->n, vlr->n);
-							if(vlr->v4->flag) VECCOPY(vlr->v4->n, vlr->n);
 						}
 					}
 				}