Changes in code to allow double sided energy, but it's not possible

to activate it. Added comment in code how to enable it for those who
like to play (search for translu)

What doesnt work - according to me not satisfying - is fact that radiosity
hemicubes alias badly on short distances, so interior light doesn't spread
well.

4 files changed, 35 insertions, 9 deletions

diff --git a/source/blender/radiosity/extern/include/radio_types.h b/source/blender/radiosity/extern/include/radio_types.h
index 4d5e56d7a15..910b50e4373 100644
--- a/source/blender/radiosity/extern/include/radio_types.h
+++ b/source/blender/radiosity/extern/include/radio_types.h
@@ -70,6 +70,7 @@ typedef struct RadView {
 #define RAD_SHOOT		2
 #define RAD_SUBDIV		4
 #define RAD_BACKFACE	8
+#define RAD_TWOSIDED	16
 
 
 typedef struct RNode {					/* length: 76 */
diff --git a/source/blender/radiosity/intern/source/radfactors.c b/source/blender/radiosity/intern/source/radfactors.c
index fb66f994cbc..cbe861fa443 100644
--- a/source/blender/radiosity/intern/source/radfactors.c
+++ b/source/blender/radiosity/intern/source/radfactors.c
@@ -524,6 +524,7 @@ void rad_init_energy()
 void progressiverad()
 {
 	RPatch *shoot;
+	float unshot[3];
 	int it= 0;
 
 	rad_printstatus();
@@ -539,8 +540,16 @@ void progressiverad()
 		
 		drawpatch_ext(shoot, 0x88FF00);
 
+		if(shoot->first->f & RAD_TWOSIDED) {
+			VECCOPY(unshot, shoot->unshot);
+			VecMulf(shoot->norm, -1.0);
+			if(makeformfactors(shoot))
+				applyformfactors(shoot);
+			VecMulf(shoot->norm, -1.0);
+			VECCOPY(shoot->unshot, unshot);
+		}
+	
 		if( makeformfactors(shoot) ) {
-		
 			applyformfactors(shoot);
 	
 			it++;
diff --git a/source/blender/radiosity/intern/source/radpreprocess.c b/source/blender/radiosity/intern/source/radpreprocess.c
index 80c6294db02..1f2f8bc2a89 100644
--- a/source/blender/radiosity/intern/source/radpreprocess.c
+++ b/source/blender/radiosity/intern/source/radpreprocess.c
@@ -459,6 +459,9 @@ void rad_collect_meshes()
 						rp->emit[1]*= rp->ref[1];
 						rp->emit[2]*= rp->ref[2];
 
+// uncommented, this is not satisfying, but i leave it in code for now (ton)						
+//						if(ma->translucency!=0.0) rn->f |= RAD_TWOSIDED;
+
 						nodevert= (VeNoCo **)&(rn->v1);
 						for(b=0; b<rp->type; b++) {
 							rp->cent[0]+= (*nodevert)->v[0];
diff --git a/source/blender/radiosity/intern/source/radrender.c b/source/blender/radiosity/intern/source/radrender.c
index 61d069ce587..6c94d3f8da9 100644
--- a/source/blender/radiosity/intern/source/radrender.c
+++ b/source/blender/radiosity/intern/source/radrender.c
@@ -127,9 +127,8 @@ static void backface_test_rr(VlakRen *shoot)
 	for(a=0; a<R.totvlak; a++) {
 		if((a & 255)==0) vlr= R.blovl[a>>8]; else vlr++;
 		if(vlr->radface) {
-			rf= vlr->radface;
 			if(vlr!=shoot) {
-		
+				rf= vlr->radface;
 				VecSubf(tvec, shoot->radface->cent, rf->cent);
 				
 				if( tvec[0]*rf->norm[0]+ tvec[1]*rf->norm[1]+ tvec[2]*rf->norm[2] < 0.0) {		
@@ -244,7 +243,8 @@ static void applyformfactors_rr(VlakRen *shoot)
 				r= (*fp)*unr*ref[0];
 				g= (*fp)*ung*ref[1];
 				b= (*fp)*unb*ref[2];
-	
+				
+				// if(rf->flag & RAD_BACKFACE) {
 				
 				rf->totrad[0]+= r;
 				rf->totrad[1]+= g;
@@ -267,21 +267,32 @@ static void progressiverad_rr()
 {
 	extern void RE_local_timecursor(int);	// RE_callbacks.c
 	VlakRen *shoot;
+	float unshot[3];
 	int it= 0;
 	
 	shoot= findshoot_rr();
 	while( shoot ) {
-	
-		/* backfaces receive no energy, but are zbuffered */
+		
+		/* backfaces receive no energy, but are zbuffered... */
 		backface_test_rr(shoot);
+		
+		/* ...unless it's two sided */
+		if(shoot->radface->flag & RAD_TWOSIDED) {
+			VECCOPY(unshot, shoot->radface->unshot);
+			VecMulf(shoot->radface->norm, -1.0);
+			makeformfactors_rr(shoot);
+			applyformfactors_rr(shoot);
+			VecMulf(shoot->radface->norm, -1.0);
+			VECCOPY(shoot->radface->unshot, unshot);
+		}
+
 		/* hemi-zbuffers */
 		makeformfactors_rr(shoot);
 		/* based at RG.formfactors array, distribute shoot energy over other faces */
 		applyformfactors_rr(shoot);
-	
+		
 		it++;
 		RE_local_timecursor(it);
-		// printf("\r Radiosity step %d", it); fflush(stdout);
 		
 		clear_backface_test_rr();
 		
@@ -359,7 +370,9 @@ printf(" Rad elems: %d emittors %d\n", RG.totelem, RG.totpatch);
 				RG.min[b]= MIN2(RG.min[b], rf->cent[b]);
 				RG.max[b]= MAX2(RG.max[b], rf->cent[b]);
 			}
-			
+
+// uncommented; this isnt satisfying, but i leave it in the code for now (ton)			
+//			if(vlr->mat->translucency!=0.0) rf->flag |= RAD_TWOSIDED;
 			
 			vlr->radface= rf++;
 		}