[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [53058] trunk/blender/source/blender/ render/intern/source/convertblender.c: Bugfix IRC report

[Sergey Sharybin]

Revision: 53058
          http://projects.blender.org/scm/viewvc.php?view=rev&root=bf-blender&revision=53058
Author:   nazgul
Date:     2012-12-16 11:47:13 +0000 (Sun, 16 Dec 2012)
Log Message:
-----------
Bugfix IRC report

Curves heavily scaled down will have render artifacts

Caused by precision issues when computing average normal map
for INDEX3 surface type. Now calculation happens in local object
space instead of world space.

Modified Paths:
--------------
    trunk/blender/source/blender/render/intern/source/convertblender.c

Modified: trunk/blender/source/blender/render/intern/source/convertblender.c
===================================================================
--- trunk/blender/source/blender/render/intern/source/convertblender.c	2012-12-16 10:28:52 UTC (rev 53057)
+++ trunk/blender/source/blender/render/intern/source/convertblender.c	2012-12-16 11:47:13 UTC (rev 53058)
@@ -2820,7 +2820,7 @@
 	ListBase disp={NULL, NULL};
 	Material **matar;
 	float *data, *fp, *orco=NULL;
-	float n[3], mat[4][4];
+	float n[3], mat[4][4], nmat[4][4];
 	int nr, startvert, a, b;
 	int need_orco=0, totmat;
 
@@ -2835,6 +2835,11 @@
 	mult_m4_m4m4(mat, re->viewmat, ob->obmat);
 	invert_m4_m4(ob->imat, mat);
 
+	/* local object -> world space transform for normals */
+	copy_m4_m4(nmat, mat);
+	transpose_m4(nmat);
+	invert_m4(nmat);
+
 	/* material array */
 	totmat= ob->totcol+1;
 	matar= MEM_callocN(sizeof(Material*)*totmat, "init_render_surf matar");
@@ -2891,13 +2896,20 @@
 					zero_v3(n);
 					index= dl->index;
 					for (a=0; a<dl->parts; a++, index+=3) {
+						int v1 = index[0], v2 = index[1], v3 = index[2];
+						float *co1 = &dl->verts[v1 * 3],
+						      *co2 = &dl->verts[v2 * 3],
+						      *co3 = &dl->verts[v3 * 3];
+
 						vlr= RE_findOrAddVlak(obr, obr->totvlak++);
-						vlr->v1= RE_findOrAddVert(obr, startvert+index[0]);
-						vlr->v2= RE_findOrAddVert(obr, startvert+index[1]);
-						vlr->v3= RE_findOrAddVert(obr, startvert+index[2]);
+						vlr->v1= RE_findOrAddVert(obr, startvert + v1);
+						vlr->v2= RE_findOrAddVert(obr, startvert + v2);
+						vlr->v3= RE_findOrAddVert(obr, startvert + v3);
 						vlr->v4= NULL;
-						if (area_tri_v3(vlr->v3->co, vlr->v2->co, vlr->v1->co)>FLT_EPSILON10) {
-							normal_tri_v3(tmp, vlr->v3->co, vlr->v2->co, vlr->v1->co);
+
+						/* to prevent float accuracy issues, we calculate normal in local object space (not world) */
+						if (area_tri_v3(co3, co2, co1)>FLT_EPSILON10) {
+							normal_tri_v3(tmp, co3, co2, co1);
 							add_v3_v3(n, tmp);
 						}
 
@@ -2906,6 +2918,8 @@
 						vlr->ec= 0;
 					}
 
+					/* transform normal to world space */
+					mul_m4_v3(nmat, n);
 					normalize_v3(n);
 
 					/* vertex normals */