- another fresnel improvement. :)

  At last irc meeting, eeshlo pointed to an error in the code. It didn't
  use the IOR value correctly. This has been solved. So how it works now:
  - the IOR button value influences (very subtle) the fresnel effect.
    Only for realism diehards.
  - the Fresnel value (slider) now denotes the power in the function
    rf + (1-rf) * (1-c)^5
    where rf= rf = ((ior-1)/(ior+1))^2
    and c the dot-product ray/normal.
  - so, set the slider at '5' and you have real fresnel. Lower values
    for interesting artistic effects.

- put back the forgotten code for gaussian corrected sampling during
  antialising render. Normally, each sub-pixel sample in Blender counts
  equally, and together make up the pixel color.
  With 'Gauss' option set (F10 menu) each sub-pixel sample creates a small
  weighted mask with variable size, which (can) affect neighbouring pixels
  as well. The result is smoother edges, less sensitive for gamma, and
  well suited to reduce motion-aliasing (when things move extreme slow).
  This is result of *long* period of research in NeoGeo days, and based on
  every scientific sampling/reconstructing theory we could find. Plus a
  little bit of our selves. :)

- I should write once how blender constructs Jitter tables for sub-sampling.
  this is a very nice method, and superior to normal block filter or random
  jittering... time!

9 files changed, 51 insertions, 59 deletions

diff --git a/source/blender/blenloader/intern/readfile.c b/source/blender/blenloader/intern/readfile.c
index 068fca17726..f55d0fa78f7 100644
--- a/source/blender/blenloader/intern/readfile.c
+++ b/source/blender/blenloader/intern/readfile.c
@@ -3931,13 +3931,14 @@ static void do_versions(Main *main)
 	}	
 	if(main->versionfile <= 231) {	
 		Material *ma= main->mat.first;
+		Scene *sce;
 		while(ma) {
 			if(ma->ang==0.0) {
 				ma->ang= 1.0;
 				ma->ray_depth= 2;
 				ma->ray_depth_tra= 2;
-				ma->fresnel_tra= 1.0;
-				ma->fresnel_mir= 1.0;
+				ma->fresnel_tra= 0.0;
+				ma->fresnel_mir= 0.0;
 			}
 			else if(ma->ang<1.0) {		// temporal, because of IOR & fresnel change
 				ma-> ang= 1.0/ma->ang;
@@ -3946,6 +3947,11 @@ static void do_versions(Main *main)
 			}
 			ma= ma->id.next;
 		}
+		sce= main->scene.first;
+		while(sce) {
+			if(sce->r.gauss==0.0) sce->r.gauss= 1.0;
+			sce= sce->id.next;
+		}
 	}
 	/* don't forget to set version number in blender.c! */
 }
diff --git a/source/blender/makesdna/DNA_scene_types.h b/source/blender/makesdna/DNA_scene_types.h
index 48c448187f6..679a33ac492 100644
--- a/source/blender/makesdna/DNA_scene_types.h
+++ b/source/blender/makesdna/DNA_scene_types.h
@@ -200,12 +200,12 @@ typedef struct RenderData {
 
 	/** For unified renderer: reduce intensity on boundaries with
 	 * identical materials with this number.*/
-	short same_mat_redux, pad_3[2];
+	short same_mat_redux;
 	
 	/**
 	 * The gamma for the normal rendering. Used when doing
 	 * oversampling, to correctly blend subpixels to pixels.  */
-	float gamma;
+	float gamma, gauss;
 	/** post-production settings. Don't really belong here */
 	float postmul, postgamma, postadd, postigamma;
 	
@@ -282,6 +282,7 @@ typedef struct Scene {
 #define R_MBLUR			0x4000
 #define R_UNIFIED       0x8000
 #define R_RAYTRACE      0x10000
+#define R_GAUSS      	0x20000
 
 /* scemode */
 #define R_DOSEQ			0x0001
diff --git a/source/blender/render/intern/include/rendercore.h b/source/blender/render/intern/include/rendercore.h
index c463d9cdaae..c8ad75a4f00 100644
--- a/source/blender/render/intern/include/rendercore.h
+++ b/source/blender/render/intern/include/rendercore.h
@@ -58,7 +58,7 @@ void shade_input_set_coords(ShadeInput *shi, float u, float v, int i1, int i2, i
 void shade_color(struct ShadeInput *shi, ShadeResult *shr);
 void shade_lamp_loop(struct ShadeInput *shi, ShadeResult *shr, int mask);
 
-float fresnel_fac(float *view, float *vn, float fresnel);
+float fresnel_fac(float *view, float *vn, float fresnel, float fac);
 void calc_R_ref(struct ShadeInput *shi);
 float spec(float inp, int hard);
 
diff --git a/source/blender/render/intern/source/initrender.c b/source/blender/render/intern/source/initrender.c
index 8edde6563b7..15b401d3d66 100644
--- a/source/blender/render/intern/source/initrender.c
+++ b/source/blender/render/intern/source/initrender.c
@@ -168,9 +168,12 @@ void RE_free_render_data()
 
 float  calc_weight(float *weight, int i, int j)
 {
-	float x, y, dist, totw= 0.0;
+	float x, y, dist, totw= 0.0, fac;
 	int a;
 
+	fac= R.r.gauss*R.r.gauss;
+	fac*= fac;
+
 	for(a=0; a<R.osa; a++) {
 		x= jit[a][0]-0.5+ i;
 		y= jit[a][1]-0.5+ j;
@@ -179,15 +182,15 @@ float  calc_weight(float *weight, int i, int j)
 		weight[a]= 0.0;
 
 		/* gaussian weighting has been cancelled */
-		//if(R.r.mode & R_GAUSS) {
-		//	if(dist<1.5) {
-		//		x = dist*1.5;
-		//		weight[a]= (1.0/exp(x*x) - 1.0/exp(1.5*1.5*1.5*1.5));
-		//	}
-		//}
-		//else {
+		if(R.r.mode & R_GAUSS) {
+			if(dist<R.r.gauss) {
+				x = dist*R.r.gauss;
+				weight[a]= (1.0/exp(x*x) - 1.0/exp(fac));
+			}
+		}
+		else {
 			if(i==0 && j==0) weight[a]= 1.0;
-		//}
+		}
 
 		totw+= weight[a];
 
diff --git a/source/blender/render/intern/source/ray.c b/source/blender/render/intern/source/ray.c
index 04ca80171d5..030dbb7847b 100644
--- a/source/blender/render/intern/source/ray.c
+++ b/source/blender/render/intern/source/ray.c
@@ -1366,7 +1366,7 @@ static void traceray(short depth, float *start, float *vec, float *col, VlakRen
 
 			if(shi.matren->mode & MA_RAYMIRROR) {
 				f= shi.matren->ray_mirror;
-				if(f!=0.0) f*= fresnel_fac(shi.view, shi.vn, shi.matren->fresnel_mir);
+				if(f!=0.0) f*= fresnel_fac(shi.view, shi.vn, shi.matren->ang, shi.matren->fresnel_mir);
 			}
 			else f= 0.0;
 			
@@ -1619,7 +1619,7 @@ void ray_trace(ShadeInput *shi, ShadeResult *shr, int mask)
 		
 		if(do_mir) {
 		
-			i= shi->matren->ray_mirror*fresnel_fac(shi->view, shi->vn, shi->matren->fresnel_mir);
+			i= shi->matren->ray_mirror*fresnel_fac(shi->view, shi->vn, shi->matren->ang, shi->matren->fresnel_mir);
 			if(i!=0.0) {
 				fr= shi->matren->mirr;
 				fg= shi->matren->mirg;
diff --git a/source/blender/render/intern/source/rendercore.c b/source/blender/render/intern/source/rendercore.c
index 5342fef9934..cb7fa627e3c 100644
--- a/source/blender/render/intern/source/rendercore.c
+++ b/source/blender/render/intern/source/rendercore.c
@@ -1500,46 +1500,29 @@ void calc_R_ref(ShadeInput *shi)
 
 }
 
-float fresnel_fac(float *view, float *vn, float ior)
+float fresnel_fac(float *view, float *vn, float ior, float fac)
 {
 	float rf, t1, t2;
 	
-	if(ior==1.0) return 1.0;
-
-	t1= (view[0]*vn[0] + view[1]*vn[1] + view[2]*vn[2]);
-	if(t1>0.0) t1= 1.0+t1;
-	else t1 = 1.0-t1;
+	if(fac==0.0) return 1.0;
 	
-	t2 = t1*t1;
-	t2= (ior + (1.0-ior)*t2*t2*t1);
-
-	if(t2<0.0) return 0.0;
-	else if(t2>1.0) return 1.0;
-	return t2;
-}
-#if 0
-/* correctness fresnel, schlick approx */
-float fresnel_fac1(float *view, float *vn, float ior)
-{
-	float rf, t1, t2;
-	
-	if(ior==1.0) return 1.0;
-
-	rf = ((ior-1)/(ior+1));
+	rf = ((ior-1.0)/(ior+1.0));
 	rf*= rf;
-	
+
 	t1= (view[0]*vn[0] + view[1]*vn[1] + view[2]*vn[2]);
 	if(t1>0.0) t1= 1.0-t1;
 	else t1 = 1.0+t1;
 	
-	t2 = t1*t1;
-	t2= (rf + (1.0-rf)*t2*t2*t1);
+	if(fac==5.0) {
+		t2 = t1*t1;
+		t2= rf + (1.0-rf)*t1*t2*t2;
+	}
+	else t2= rf + (1.0-rf)*pow(t1, fac);
 
 	if(t2<0.0) return 0.0;
 	else if(t2>1.0) return 1.0;
 	return t2;
 }
-#endif
 
 void shade_color(ShadeInput *shi, ShadeResult *shr)
 {
@@ -1564,7 +1547,7 @@ void shade_color(ShadeInput *shi, ShadeResult *shr)
 
 	if(ma->mode & (MA_ZTRA|MA_RAYTRANSP)) {
 		if(ma->fresnel_tra!=1.0) 
-			ma->alpha*= fresnel_fac(shi->view, shi->vn, ma->fresnel_tra);
+			ma->alpha*= fresnel_fac(shi->view, shi->vn, ma->ang, ma->fresnel_tra);
 	}
 
 	shr->diff[0]= ma->r;
@@ -1896,7 +1879,7 @@ void shade_lamp_loop(ShadeInput *shi, ShadeResult *shr, int mask)
 
 	if(ma->mode & (MA_ZTRA|MA_RAYTRANSP)) {
 		if(ma->fresnel_tra!=1.0) 
-			ma->alpha*= fresnel_fac(shi->view, shi->vn, ma->fresnel_tra);
+			ma->alpha*= fresnel_fac(shi->view, shi->vn, ma->ang, ma->fresnel_tra);
 
 		if(ma->spectra!=0.0) {
 
diff --git a/source/blender/src/buttons_scene.c b/source/blender/src/buttons_scene.c
index a9ba3f66beb..4583fd8d813 100644
--- a/source/blender/src/buttons_scene.c
+++ b/source/blender/src/buttons_scene.c
@@ -1054,16 +1054,17 @@ static void render_panel_render()
 	uiDefButS(block, ROW,B_DIFF,"75%",			565,90,36,20,&G.scene->r.size,1.0,75.0, 0, 0, "Set render size to 3/4 of defined size");
 	uiDefButS(block, ROW,B_DIFF,"50%",			604,90,40,20,&G.scene->r.size,1.0,50.0, 0, 0, "Set render size to 1/2 of defined size");
 	uiDefButS(block, ROW,B_DIFF,"25%",			647,90,39,20,&G.scene->r.size,1.0,25.0, 0, 0, "Set render size to 1/4 of defined size");
-	uiBlockEndAlign(block);
 	
-	uiDefButI(block, TOG|BIT|6,0,"Fields", 564,42,90,31,&G.scene->r.mode, 0, 0, 0, 0, "Enables field rendering");
 	uiBlockBeginAlign(block);
-	uiDefButI(block, TOG|BIT|13,0,"Odd",	655,57,30,16,&G.scene->r.mode, 0, 0, 0, 0, "Enables Odd field first rendering (Default: Even field)");
-	uiDefButI(block, TOG|BIT|7,0,"x",		655,42,30,15,&G.scene->r.mode, 0, 0, 0, 0, "Disables time difference in field calculations");
-	uiBlockEndAlign(block);
+	uiDefButI(block, TOG|BIT|6,0,"Fields",  564,50,60,23,&G.scene->r.mode, 0, 0, 0, 0, "Enables field rendering");
+	uiDefButI(block, TOG|BIT|13,0,"Odd",	624,50,40,23,&G.scene->r.mode, 0, 0, 0, 0, "Enables Odd field first rendering (Default: Even field)");
+	uiDefButI(block, TOG|BIT|7,0,"x",		655,50,20,23,&G.scene->r.mode, 0, 0, 0, 0, "Disables time difference in field calculations");
+
+	uiDefButI(block, TOG|BIT|17,0,"Gauss",	564,30,60,20, &G.scene->r.mode, 0, 0, 0, 0, "Enable Gauss sampling filter for antialiasing");
+	uiDefButF(block, NUM,B_DIFF,"",			624,30,60,20,&G.scene->r.gauss,0.5, 2.0, 0, 0, "Sets the Gauss filter size)");
 	
-	uiDefButI(block, TOG|BIT|9,REDRAWVIEWCAM, "Border",	565,11,58,24, &G.scene->r.mode, 0, 0, 0, 0, "Render a small cut-out of the image");
-	uiDefButI(block, TOG|BIT|2,0, "Gamma",	626,11,58,24, &G.scene->r.mode, 0, 0, 0, 0, "Enable gamma correction");
+	uiDefButI(block, TOG|BIT|9,REDRAWVIEWCAM, "Border",	564,10,60,20, &G.scene->r.mode, 0, 0, 0, 0, "Render a small cut-out of the image");
+	uiDefButI(block, TOG|BIT|2,0, "Gamma",	624,10,60,20, &G.scene->r.mode, 0, 0, 0, 0, "Enable gamma correction");
 
 
 }
diff --git a/source/blender/src/buttons_shading.c b/source/blender/src/buttons_shading.c
index e182024910b..f228bee4fde 100644
--- a/source/blender/src/buttons_shading.c
+++ b/source/blender/src/buttons_shading.c
@@ -2025,9 +2025,7 @@ void do_matbuts(unsigned short event)
 	case B_MATRAYTRANSP:
 		ma= G.buts->lockpoin;
 		if(ma) {
-			// set ztra when you disable ray-tra, is nicer
-			if(ma->mode & MA_RAYTRANSP) ma->mode &= ~MA_ZTRA;
-			else ma->mode |= MA_ZTRA;
+			ma->mode &= ~MA_ZTRA;
 			allqueue(REDRAWBUTSSHADING, 0);
 			BIF_preview_changed(G.buts);
 		}
@@ -2256,7 +2254,7 @@ static void material_panel_tramir(Material *ma)
 	uiBlockBeginAlign(block);
 	uiDefButF(block, NUMSLI, B_MATPRV, "RayMir ",	10,180,200,19, &(ma->ray_mirror), 0.0, 1.0, 100, 2, "Sets the amount mirror reflection for raytrace");
 	uiDefButI(block, TOG|BIT|18, B_MATPRV,"Ray Mirror",210,180,100,19, &(ma->mode), 0, 0, 0, 0, "Enables raytracing for mirror reflection rendering");
-	uiDefButF(block, NUMSLI, B_MATPRV, "Fresnel ",	10,160,200,19, &(ma->fresnel_mir), 1.0, 1.5, 10, 2, "Amount of Fresnel for mirror reflection");
+	uiDefButF(block, NUMSLI, B_MATPRV, "Fresnel ",	10,160,200,19, &(ma->fresnel_mir), 0.0, 5.0, 100, 2, "Power of Fresnel for mirror reflection");
 	uiDefButS(block, NUM, B_MATPRV, "Depth:",		210,160,100,19, &(ma->ray_depth), 0.0, 10.0, 100, 0, "Amount of inter-reflections calculated maximal ");
 
 	uiBlockBeginAlign(block);
@@ -2266,7 +2264,7 @@ static void material_panel_tramir(Material *ma)
 	uiDefButF(block, NUMSLI, B_MATPRV, "IOR ",		10,110,200,19, &(ma->ang), 1.0, 3.0, 100, 2, "Sets the angular index of refraction for raytrace");
 	uiDefButI(block, TOG|BIT|17, B_MATRAYTRANSP,"Ray Transp",210,110,100,19, &(ma->mode), 0, 0, 0, 0, "Enables raytracing for transparency rendering");
 
-	uiDefButF(block, NUMSLI, B_MATPRV, "Fresnel ",	10,90,200,19, &(ma->fresnel_tra), 1.0, 1.5, 10, 2, "Amount of Fresnel for transparency");
+	uiDefButF(block, NUMSLI, B_MATPRV, "Fresnel ",	10,90,200,19, &(ma->fresnel_tra), 0.0, 5.0, 100, 2, "Power of Fresnel for transparency");
 	uiDefButS(block, NUM, B_MATPRV, "Depth:",		210,90,100,19, &(ma->ray_depth_tra), 0.0, 10.0, 100, 0, "Amount of refractions calculated maximal ");
 
 	uiBlockBeginAlign(block);
diff --git a/source/blender/src/previewrender.c b/source/blender/src/previewrender.c
index 1dbed2795ba..b5554dbfccd 100644
--- a/source/blender/src/previewrender.c
+++ b/source/blender/src/previewrender.c
@@ -701,7 +701,7 @@ static void refraction_prv(int *x, int *y, float *n, float index)
 
 static void shade_preview_pixel(ShadeInput *shi, float *vec, int x, int y,char *rect, int smooth)
 {
-	extern float fresnel_fac(float *view, float *vn, float fresnel);
+	extern float fresnel_fac(float *view, float *vn, float ior, float fac);
 	Material *mat;
 	float v1,inp, inprspec=0, isr=0.0, isb=0.0, isg=0.0;
 	float ir=0.0, ib=0.0, ig=0.0;
@@ -860,7 +860,7 @@ static void shade_preview_pixel(ShadeInput *shi, float *vec, int x, int y,char *
 			/* scale */
 			div= (0.85*shi->ref[1]);
 			
-			shi->refcol[0]= mat->ray_mirror*fresnel_fac(view, shi->vn, mat->fresnel_mir);
+			shi->refcol[0]= mat->ray_mirror*fresnel_fac(view, shi->vn, mat->ang, mat->fresnel_mir);
 
 			if(div<0.0) {
 				/* minus 0.5 prevents too many small tiles in distance */
@@ -907,7 +907,7 @@ static void shade_preview_pixel(ShadeInput *shi, float *vec, int x, int y,char *
 	
 	if(mat->mode & (MA_ZTRA|MA_RAYTRANSP)) 
 		if(mat->fresnel_tra!=0.0) 
-			alpha*= fresnel_fac(view, shi->vn, mat->fresnel_tra);
+			alpha*= fresnel_fac(view, shi->vn, mat->ang, mat->fresnel_tra);
 	
 		/* ztra shade */
 	if(mat->spectra!=0.0) {