[Bf-blender-cvs] SVN commit: /data/svn/bf-blender [13764] trunk/blender/source/blender/ render/intern/source/raytrace.c:

[Brecht Van Lommel]

Revision: 13764
          http://projects.blender.org/plugins/scmsvn/viewcvs.php?view=rev&root=bf-blender&revision=13764
Author:   blendix
Date:     2008-02-19 13:13:35 +0100 (Tue, 19 Feb 2008)

Log Message:
-----------

Bugfix: this adds some epsilons (FLT_EPSILON, so quite small) to the
raytracing intersection code, to avoid rays slipping through between
triangles, this would mostly show up with sceen aligned quads and
baking of height maps for example. Epsilon's are not pretty, but I
haven't found a reliable way around them.

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

Modified: trunk/blender/source/blender/render/intern/source/raytrace.c
===================================================================
--- trunk/blender/source/blender/render/intern/source/raytrace.c	2008-02-19 11:07:09 UTC (rev 13763)
+++ trunk/blender/source/blender/render/intern/source/raytrace.c	2008-02-19 12:13:35 UTC (rev 13764)
@@ -635,6 +635,8 @@
 
 /* ************ raytracer **************** */
 
+#define ISECT_EPSILON ((float)FLT_EPSILON)
+
 /* only for self-intersecting test with current render face (where ray left) */
 static int intersection2(RayFace *face, int ob, RayObjectTransformFunc transformfunc, RayCoordsFunc coordsfunc, void *userdata, float r0, float r1, float r2, float rx1, float ry1, float rz1)
 {
@@ -692,13 +694,13 @@
 	if(divdet!=0.0f) {
 		u1= det1/divdet;
 
-		if(u1<=0.0f) {
+		if(u1<ISECT_EPSILON) {
 			det= t00*(m1*r2-m2*r1);
 			det+= t01*(m2*r0-m0*r2);
 			det+= t02*(m0*r1-m1*r0);
 			v= det/divdet;
 
-			if(v<=0.0f && (u1 + v) >= -1.0f) {
+			if(v<ISECT_EPSILON && (u1 + v) > -(1.0f+ISECT_EPSILON)) {
 				return 1;
 			}
 		}
@@ -714,13 +716,13 @@
 		if(divdet!=0.0f) {
 			u2= det1/divdet;
 		
-			if(u2<=0.0f) {
+			if(u2<ISECT_EPSILON) {
 				det= t20*(m1*r2-m2*r1);
 				det+= t21*(m2*r0-m0*r2);
 				det+= t22*(m0*r1-m1*r0);
 				v= det/divdet;
 	
-				if(v<=0.0f && (u2 + v) >= -1.0f) {
+				if(v<ISECT_EPSILON && (u2 + v) >= -(1.0f+ISECT_EPSILON)) {
 					return 2;
 				}
 			}
@@ -860,7 +862,7 @@
 
 		divdet= 1.0f/divdet;
 		u= det1*divdet;
-		if(u<0.0f && u>-1.0f) {
+		if(u<ISECT_EPSILON && u>-(1.0f+ISECT_EPSILON)) {
 			float v, cros0, cros1, cros2;
 			
 			cros0= m1*t02-m2*t01;
@@ -868,11 +870,11 @@
 			cros2= m0*t01-m1*t00;
 			v= divdet*(cros0*r0 + cros1*r1 + cros2*r2);
 
-			if(v<0.0f && (u + v) > -1.0f) {
+			if(v<ISECT_EPSILON && (u + v) > -(1.0f+ISECT_EPSILON)) {
 				float labda;
 				labda= divdet*(cros0*t10 + cros1*t11 + cros2*t12);
 
-				if(labda>0.0f && labda<1.0f) {
+				if(labda>-ISECT_EPSILON && labda<1.0f+ISECT_EPSILON) {
 					is->labda= labda;
 					is->u= u; is->v= v;
 					ok= 1;
@@ -893,18 +895,18 @@
 			divdet= 1.0f/divdet;
 			u = det1*divdet;
 			
-			if(u<0.0f && u>-1.0f) {
+			if(u<ISECT_EPSILON && u>-(1.0f+ISECT_EPSILON)) {
 				float v, cros0, cros1, cros2;
 				cros0= m1*t22-m2*t21;
 				cros1= m2*t20-m0*t22;
 				cros2= m0*t21-m1*t20;
 				v= divdet*(cros0*r0 + cros1*r1 + cros2*r2);
 	
-				if(v<0.0f && (u + v) > -1.0f) {
+				if(v<ISECT_EPSILON && (u + v) >-(1.0f+ISECT_EPSILON)) {
 					float labda;
 					labda= divdet*(cros0*t10 + cros1*t11 + cros2*t12);
 					
-					if(labda>0.0f && labda<1.0f) {
+					if(labda>-ISECT_EPSILON && labda<1.0f+ISECT_EPSILON) {
 						ok= 2;
 						is->labda= labda;
 						is->u= u; is->v= v;