Render control feature: shader-level shadowbuffer bias

Lampbuffers require painful bias tweaking (to prevent aliasing or to
get shadow detail). Sometimes you want this different per object, like
for gras you want less shadow detail, but for the ground you want high
detail. This feature allows to tweak it.

The new "LBias" slider is in shader panel, bottom. Ugly! But, thats for
later...

6 files changed, 17 insertions, 10 deletions

diff --git a/source/blender/makesdna/DNA_material_types.h b/source/blender/makesdna/DNA_material_types.h
index 1deda6a29d5..d885bfcae82 100644
--- a/source/blender/makesdna/DNA_material_types.h
+++ b/source/blender/makesdna/DNA_material_types.h
@@ -88,8 +88,10 @@ typedef struct Material {
 	float strand_min, strand_widthfade;
 	char strand_uvname[32];
 	
-	float sbias;			/* shadow bias */
+	float sbias;			/* shadow bias to prevent terminator prob */
+	float lbias;			/* factor to multiply lampbias with (0.0 = no mult) */
 	float shad_alpha;		/* in use for irregular shadowbuffer */
+	float padf;				/* free padding, take me! */
 	
 	/* for buttons and render*/
 	char rgbsel, texact, pr_type, use_nodes;
diff --git a/source/blender/render/intern/include/shadbuf.h b/source/blender/render/intern/include/shadbuf.h
index 20a266f8579..c5d8f2690c7 100644
--- a/source/blender/render/intern/include/shadbuf.h
+++ b/source/blender/render/intern/include/shadbuf.h
@@ -57,7 +57,7 @@ void threaded_makeshadowbufs(struct Render *re);
  * @param inp The inproduct between viewvector and ?
  *
  */
-float testshadowbuf(struct ShadBuf *shb, float *rco, float *dxco, float *dyco, float inp);	
+float testshadowbuf(struct ShadBuf *shb, float *rco, float *dxco, float *dyco, float inp, float mat_bias);	
 
 /**
  * Determines the shadow factor for lamp <lar>, between <p1>
diff --git a/source/blender/render/intern/source/pixelshading.c b/source/blender/render/intern/source/pixelshading.c
index a1088d1a920..4e589789412 100644
--- a/source/blender/render/intern/source/pixelshading.c
+++ b/source/blender/render/intern/source/pixelshading.c
@@ -182,7 +182,7 @@ static void render_lighting_halo(HaloRen *har, float *colf)
 					inp= vn[0]*lv[0] + vn[1]*lv[1] + vn[2]*lv[2];
 					if(inp>0.0) {
 						/* testshadowbuf==0.0 : 100% shadow */
-						shadfac = testshadowbuf(lar->shb, rco, dco, dco, inp);
+						shadfac = testshadowbuf(lar->shb, rco, dco, dco, inp, 0.0f);
 						if( shadfac>0.0 ) {
 							shadfac*= inp*soft*lar->energy;
 							ir -= shadfac;
@@ -219,7 +219,7 @@ static void render_lighting_halo(HaloRen *har, float *colf)
 		if(i> -0.41) {			/* heuristic valua! */
 			shadfac= 1.0;
 			if(lar->shb) {
-				shadfac = testshadowbuf(lar->shb, rco, dco, dco, inp);
+				shadfac = testshadowbuf(lar->shb, rco, dco, dco, inp, 0.0f);
 				if(shadfac==0.0) continue;
 				i*= shadfac;
 			}
diff --git a/source/blender/render/intern/source/shadbuf.c b/source/blender/render/intern/source/shadbuf.c
index 8e37606cdf9..34fd5b0154a 100644
--- a/source/blender/render/intern/source/shadbuf.c
+++ b/source/blender/render/intern/source/shadbuf.c
@@ -648,11 +648,11 @@ static float readshadowbuf(ShadBuf *shb, ShadSampleBuf *shsample, int bias, int
 
 /* the externally called shadow testing (reading) function */
 /* return 1.0: no shadow at all */
-float testshadowbuf(ShadBuf *shb, float *rco, float *dxco, float *dyco, float inp)
+float testshadowbuf(ShadBuf *shb, float *rco, float *dxco, float *dyco, float inp, float mat_bias)
 {
 	ShadSampleBuf *shsample;
 	float fac, co[4], dx[3], dy[3], shadfac=0.0f;
-	float xs1,ys1, siz, *jit, *weight, xres, yres;
+	float xs1,ys1, siz, *jit, *weight, xres, yres, biasf;
 	int xs, ys, zs, bias, *rz;
 	short a, num;
 	
@@ -689,10 +689,12 @@ float testshadowbuf(ShadBuf *shb, float *rco, float *dxco, float *dyco, float in
 	num= shb->samp*shb->samp;
 	fac= shb->soft;
 	
+	if(mat_bias!=0.0f) biasf= shb->bias*mat_bias;
+	else biasf= shb->bias;
 	/* with inp==1.0, bias is half the size. correction value was 1.1, giving errors 
 	   on cube edges, with one side being almost frontal lighted (ton)  */
-	bias= (1.5f-inp*inp)*shb->bias;
-
+	bias= (1.5f-inp*inp)*biasf;
+	
 	if(num==1) {
 		for(shsample= shb->buffers.first; shsample; shsample= shsample->next)
 			shadfac += readshadowbuf(shb, shsample, bias, (int)xs1, (int)ys1, zs);
diff --git a/source/blender/render/intern/source/shadeoutput.c b/source/blender/render/intern/source/shadeoutput.c
index 0823ae146f7..ca81d456487 100644
--- a/source/blender/render/intern/source/shadeoutput.c
+++ b/source/blender/render/intern/source/shadeoutput.c
@@ -1054,7 +1054,7 @@ void lamp_get_shadow(LampRen *lar, ShadeInput *shi, float inp, float *shadfac, i
 			if(lar->buftype==LA_SHADBUF_IRREGULAR)
 				shadfac[3]= ISB_getshadow(shi, lar->shb);
 			else
-				shadfac[3] = testshadowbuf(lar->shb, shi->co, shi->dxco, shi->dyco, inp);
+				shadfac[3] = testshadowbuf(lar->shb, shi->co, shi->dxco, shi->dyco, inp, shi->mat->lbias);
 		}
 		else if(lar->mode & LA_SHAD_RAY) {
 			ray_shadow(shi, lar, shadfac);
diff --git a/source/blender/src/buttons_shading.c b/source/blender/src/buttons_shading.c
index 2e73a6db06f..c7ba1430748 100644
--- a/source/blender/src/buttons_shading.c
+++ b/source/blender/src/buttons_shading.c
@@ -3714,7 +3714,7 @@ static void material_panel_shading(Material *ma)
 	uiBlock *block;
 	
 	block= uiNewBlock(&curarea->uiblocks, "material_panel_shading", UI_EMBOSS, UI_HELV, curarea->win);
-	if(uiNewPanel(curarea, block, "Shaders", "Material", 640, 0, 318, 204)==0) return;
+	if(uiNewPanel(curarea, block, "Shaders", "Material", 640, 0, 318, 224)==0) return;
 	
 	uiSetButLock(ma->id.lib!=NULL, ERROR_LIBDATA_MESSAGE);
 	
@@ -3792,6 +3792,7 @@ static void material_panel_shading(Material *ma)
 		uiDefButF(block, NUMSLI, B_MATPRV, "SBias ",	159,30,151,19, &(ma->sbias), 0.0, 0.25, 10, 2, "Shadow bias, to prevent terminator problems on shadow boundary");
 		uiDefButF(block, NUMSLI, B_MATPRV, "Amb ",		9,10,150,19, &(ma->amb), 0.0, 1.0, 0, 0, "Sets the amount of global ambient color the material receives");
 		uiDefButF(block, NUMSLI, B_MATPRV, "Emit ",		159,10,151,19, &(ma->emit), 0.0, 2.0, 0, 0, "Sets the amount of light the material emits");
+		uiDefButF(block, NUMSLI, B_MATPRV, "LBias ",	9,-10,300,19, &(ma->lbias), 0.0, 10.0, 100, 2, "Factor to multiply shadowbuffer bias with (0 is ignore)");
 		uiBlockEndAlign(block);
 
 		uiBlockSetCol(block, TH_BUT_SETTING1);
@@ -3807,6 +3808,8 @@ static void material_panel_shading(Material *ma)
 		uiBlockBeginAlign(block);
 		uiDefIDPoinBut(block, test_grouppoin_but, ID_GR, B_MATPRV, "GR:",	9, 55, 150, 19, &ma->group, "Limit Lighting to Lamps in this Group"); 
 		uiDefButBitI(block, TOG, MA_GROUP_NOLAY, B_MATPRV,	"Exclusive",	159,55, 85,20, &(ma->mode), 0, 0, 0, 0, "The material exclusively uses Lamps in this Group");
+		
+		
 	}
 }