Bugfix #25580

Raytracing didn't show soft shadow in reflections, nor did it do any
derivative even. Added a basic version for it in raytracer now, still
needs improvement on heavily curved surfaces. But it's better!

Examples:

Glass sphere, mirror cube and sphere, look how it ignores bump and shadow
http://www.blender.org/bf/derivative256.png

in svn now:
http://www.blender.org/bf/derivative-svn.png

1 files changed, 38 insertions, 15 deletions

diff --git a/source/blender/render/intern/source/rayshade.c b/source/blender/render/intern/source/rayshade.c
index e1e0828bdd2..1bbf994d505 100644
--- a/source/blender/render/intern/source/rayshade.c
+++ b/source/blender/render/intern/source/rayshade.c
@@ -482,13 +482,44 @@ void makeraytree(Render *re)
 #endif
 }
 
+/* 	if(shi->osatex)  */
+static void shade_ray_set_derivative(ShadeInput *shi)
+{
+	float *v1= shi->v1->co;
+	float *v2= shi->v2->co;
+	float *v3= shi->v3->co;
+	float detsh, t00, t10, t01, t11, xn, yn, zn;
+	int axis1, axis2;
+	
+	/* find most stable axis to project */
+	xn= fabs(shi->facenor[0]);
+	yn= fabs(shi->facenor[1]);
+	zn= fabs(shi->facenor[2]);
+	
+	if(zn>=xn && zn>=yn) { axis1= 0; axis2= 1; }
+	else if(yn>=xn && yn>=zn) { axis1= 0; axis2= 2; }
+	else { axis1= 1; axis2= 2; }
+	
+	/* compute u,v and derivatives */
+	t00= v3[axis1]-v1[axis1]; t01= v3[axis2]-v1[axis2];
+	t10= v3[axis1]-v2[axis1]; t11= v3[axis2]-v2[axis2];
+	
+	detsh= 1.0f/(t00*t11-t10*t01);
+	t00*= detsh; t01*=detsh; 
+	t10*=detsh; t11*=detsh;
+	
+	shi->dx_u=  shi->dxco[axis1]*t11- shi->dxco[axis2]*t10;
+	shi->dx_v=  shi->dxco[axis2]*t00- shi->dxco[axis1]*t01;
+	shi->dy_u=  shi->dyco[axis1]*t11- shi->dyco[axis2]*t10;
+	shi->dy_v=  shi->dyco[axis2]*t00- shi->dyco[axis1]*t01;
+	
+}
 
 
 void shade_ray(Isect *is, ShadeInput *shi, ShadeResult *shr)
 {
 	ObjectInstanceRen *obi= (ObjectInstanceRen*)is->hit.ob;
 	VlakRen *vlr= (VlakRen*)is->hit.face;
-	int osatex= 0;
 	
 	/* set up view vector */
 	VECCOPY(shi->view, is->vec);
@@ -506,18 +537,6 @@ void shade_ray(Isect *is, ShadeInput *shi, ShadeResult *shr)
 	shi->mat= vlr->mat;
 	shade_input_init_material(shi);
 	
-	// Osa structs we leave unchanged now
-	SWAP(int, osatex, shi->osatex);
-	
-	shi->dxco[0]= shi->dxco[1]= shi->dxco[2]= 0.0f;
-	shi->dyco[0]= shi->dyco[1]= shi->dyco[2]= 0.0f;
-	
-	// but, set Osa stuff to zero where it can confuse texture code
-	if(shi->mat->texco & (TEXCO_NORM|TEXCO_REFL) ) {
-		shi->dxno[0]= shi->dxno[1]= shi->dxno[2]= 0.0f;
-		shi->dyno[0]= shi->dyno[1]= shi->dyno[2]= 0.0f;
-	}
-
 	if(vlr->v4) {
 		if(is->isect==2) 
 			shade_input_set_triangle_i(shi, obi, vlr, 2, 1, 3);
@@ -532,6 +551,8 @@ void shade_ray(Isect *is, ShadeInput *shi, ShadeResult *shr)
 	shi->v= is->v;
 	shi->dx_u= shi->dx_v= shi->dy_u= shi->dy_v=  0.0f;
 
+	if(shi->osatex)
+		shade_ray_set_derivative(shi);
 	shade_input_set_normals(shi);
 
 	shade_input_set_shade_texco(shi);
@@ -563,8 +584,6 @@ void shade_ray(Isect *is, ShadeInput *shi, ShadeResult *shr)
 		/* raytrace likes to separate the spec color */
 		VECSUB(shr->diff, shr->combined, shr->spec);
 	}	
-	
-	SWAP(int, osatex, shi->osatex);  // XXXXX!!!!
 
 }
 
@@ -720,6 +739,10 @@ static void traceray(ShadeInput *origshi, ShadeResult *origshr, short depth, flo
 		ShadeResult shr= {{0}};
 		float d= 1.0f;
 
+		/* for as long we don't have proper dx/dy transform for rays we copy over original */
+		VECCOPY(shi.dxco, origshi->dxco);
+		VECCOPY(shi.dyco, origshi->dyco);
+		
 		shi.mask= origshi->mask;
 		shi.osatex= origshi->osatex;
 		shi.depth= origshi->depth + 1;					/* only used to indicate tracing */