volume material

* data reorganisation - uses own values now instead of reusing surface material properties (i.e. an individual density value, rather than reusing alpha) Files saved with the old system won't load up the same after this.

* improved defaults and ui

2 files changed, 85 insertions, 74 deletions

diff --git a/source/blender/render/intern/source/texture.c b/source/blender/render/intern/source/texture.c
index 27cf698aabe..1b25edaab34 100644
--- a/source/blender/render/intern/source/texture.c
+++ b/source/blender/render/intern/source/texture.c
@@ -2362,7 +2362,7 @@ void do_volume_tex(ShadeInput *shi, float *xyz, int mapto_flag, float *col, floa
 			}
 			
 			
-			if((mapto_flag & (MAP_COL+MAP_COLMIR)) && (mtex->mapto & (MAP_COL+MAP_COLMIR))) {
+			if((mapto_flag & (MAP_EMISSION_COL+MAP_ABSORPTION_COL)) && (mtex->mapto & (MAP_EMISSION_COL+MAP_ABSORPTION_COL))) {
 				float tcol[3], colfac;
 				
 				/* stencil maps on the texture control slider, not texture intensity value */
@@ -2386,12 +2386,12 @@ void do_volume_tex(ShadeInput *shi, float *xyz, int mapto_flag, float *col, floa
 				}
 				
 				/* used for emit */
-				if((mapto_flag & MAP_COL) && (mtex->mapto & MAP_COL)) {
+				if((mapto_flag & MAP_EMISSION_COL) && (mtex->mapto & MAP_EMISSION_COL)) {
 					texture_rgb_blend(col, tcol, col, texres.tin, colfac, mtex->blendtype);
 				}
 				
 				/* MAP_COLMIR is abused for absorption colour at the moment */
-				if((mapto_flag & MAP_COLMIR) && (mtex->mapto & MAP_COLMIR)) {
+				if((mapto_flag & MAP_ABSORPTION_COL) && (mtex->mapto & MAP_ABSORPTION_COL)) {
 					texture_rgb_blend(col, tcol, col, texres.tin, colfac, mtex->blendtype);
 				}
 			}
@@ -2408,18 +2408,30 @@ void do_volume_tex(ShadeInput *shi, float *xyz, int mapto_flag, float *col, floa
 					}
 				}
 				
-				if((mapto_flag & MAP_EMIT) && (mtex->mapto & MAP_EMIT)) {
-					int flip= mtex->maptoneg & MAP_EMIT;
+				if((mapto_flag & MAP_EMISSION) && (mtex->mapto & MAP_EMISSION)) {
+					int flip= mtex->maptoneg & MAP_EMISSION;
 
 					*val = texture_value_blend(mtex->def_var, *val, texres.tin, varfac, mtex->blendtype, flip);
 					if(*val<0.0) *val= 0.0;
 				}
-				if((mapto_flag & MAP_ALPHA) && (mtex->mapto & MAP_ALPHA)) {
-					int flip= mtex->maptoneg & MAP_ALPHA;
+				if((mapto_flag & MAP_DENSITY) && (mtex->mapto & MAP_DENSITY)) {
+					int flip= mtex->maptoneg & MAP_DENSITY;
 
 					*val = texture_value_blend(mtex->def_var, *val, texres.tin, varfac, mtex->blendtype, flip);
 					CLAMP(*val, 0.0, 1.0);
 				}
+				if((mapto_flag & MAP_ABSORPTION) && (mtex->mapto & MAP_ABSORPTION)) {
+					int flip= mtex->maptoneg & MAP_ABSORPTION;
+					
+					*val = texture_value_blend(mtex->def_var, *val, texres.tin, varfac, mtex->blendtype, flip);
+					CLAMP(*val, 0.0, 1.0);
+				}
+				if((mapto_flag & MAP_SCATTERING) && (mtex->mapto & MAP_SCATTERING)) {
+					int flip= mtex->maptoneg & MAP_SCATTERING;
+					
+					*val = texture_value_blend(mtex->def_var, *val, texres.tin, varfac, mtex->blendtype, flip);
+					CLAMP(*val, 0.0, 1.0);
+				}
 			}
 		}
 	}
diff --git a/source/blender/render/intern/source/volumetric.c b/source/blender/render/intern/source/volumetric.c
index 04eb1b5e3bf..63c4e97f86e 100644
--- a/source/blender/render/intern/source/volumetric.c
+++ b/source/blender/render/intern/source/volumetric.c
@@ -165,82 +165,91 @@ static void vol_get_precached_scattering(ShadeInput *shi, float *scatter_col, fl
 
 float vol_get_density(struct ShadeInput *shi, float *co)
 {
-	float density = shi->mat->alpha;
+	float density = shi->mat->vol.density;
 	float density_scale = shi->mat->vol.density_scale;
 	float col[3] = {0.0, 0.0, 0.0};
 	
-	do_volume_tex(shi, co, MAP_ALPHA, col, &density);
+	do_volume_tex(shi, co, MAP_DENSITY, col, &density);
 	
 	return density * density_scale;
 }
 
-/* compute emission component, amount of radiance to add per segment
- * can be textured with 'emit' */
-void vol_get_emission(ShadeInput *shi, float *em, float *co, float density)
+/* scattering multiplier, values above 1.0 are non-physical, 
+ * but can be useful to tweak lighting */
+float vol_get_scattering_fac(ShadeInput *shi, float *co)
 {
-	float emission = shi->mat->emit;
+	float scatter = shi->mat->vol.scattering;
 	float col[3] = {0.0, 0.0, 0.0};
 	
-	VECCOPY(col, &shi->mat->r);
-	
-	do_volume_tex(shi, co, MAP_EMIT+MAP_COL, col, &emission);
+	do_volume_tex(shi, co, MAP_SCATTERING, col, &scatter);
 	
-	em[0] = em[1] = em[2] = emission * density;
-	VecMulVecf(em, em, col);
+	return scatter;
 }
 
-/* scattering multiplier, values above 1.0 are non-physical, 
- * but can be useful to tweak lighting */
-void vol_get_scattering_fac(ShadeInput *shi, float *scatter_fac, float *co, float density)
-{
-	*scatter_fac = shi->mat->vol.scattering;
-}
-
-/* phase function - determines in which directions the light 
- * is scattered in the volume relative to incoming direction 
- * and view direction */
-float vol_get_phasefunc(ShadeInput *shi, short phasefunc_type, float g, float *w, float *wp)
+/* compute emission component, amount of radiance to add per segment
+ * can be textured with 'emit' */
+void vol_get_emission(ShadeInput *shi, float *emission_col, float *co, float density)
 {
-	const float costheta = Inpf(w, wp);
+	float emission = shi->mat->vol.emission;
+	VECCOPY(emission_col, shi->mat->vol.emission_col);
 	
-	if (phasefunc_type == MA_VOL_PH_ISOTROPIC) {
-		return 1.f / (4.f * M_PI);
-	}
-	else if (phasefunc_type == MA_VOL_PH_MIEHAZY) {
-		return (0.5f + 4.5f * powf(0.5 * (1.f + costheta), 8.f)) / (4.f*M_PI);
-	}
-	else if (phasefunc_type == MA_VOL_PH_MIEMURKY) {
-		return (0.5f + 16.5f * powf(0.5 * (1.f + costheta), 32.f)) / (4.f*M_PI);
-	}
-	else if (phasefunc_type == MA_VOL_PH_RAYLEIGH) {
-		return 3.f/(16.f*M_PI) * (1 + costheta * costheta);
-	}
-	else if (phasefunc_type == MA_VOL_PH_HG) {
-		return 1.f / (4.f * M_PI) * (1.f - g*g) / powf(1.f + g*g - 2.f * g * costheta, 1.5f);
-	}
-	else if (phasefunc_type == MA_VOL_PH_SCHLICK) {
-		const float k = 1.55f * g - .55f * g * g * g;
-		const float kcostheta = k * costheta;
-		return 1.f / (4.f * M_PI) * (1.f - k*k) / ((1.f - kcostheta) * (1.f - kcostheta));
-	} else {
-		return 1.0f;
-	}
+	do_volume_tex(shi, co, MAP_EMISSION+MAP_EMISSION_COL, emission_col, &emission);
+	
+	emission_col[0] = emission_col[0] * emission * density;
+	emission_col[1] = emission_col[1] * emission * density;
+	emission_col[2] = emission_col[2] * emission * density;
 }
 
 void vol_get_absorption(ShadeInput *shi, float *absorb_col, float *co)
 {
-	float dummy = 1.0f;
-	const float absorption = shi->mat->vol.absorption;
-	
+	float absorption = shi->mat->vol.absorption;
 	VECCOPY(absorb_col, shi->mat->vol.absorption_col);
 	
-	do_volume_tex(shi, co, MAP_COLMIR, absorb_col, &dummy);
+	do_volume_tex(shi, co, MAP_ABSORPTION+MAP_ABSORPTION_COL, absorb_col, &absorption);
 	
 	absorb_col[0] = (1.0f - absorb_col[0]) * absorption;
 	absorb_col[1] = (1.0f - absorb_col[1]) * absorption;
 	absorb_col[2] = (1.0f - absorb_col[2]) * absorption;
 }
 
+
+/* phase function - determines in which directions the light 
+ * is scattered in the volume relative to incoming direction 
+ * and view direction */
+float vol_get_phasefunc(ShadeInput *shi, short phasefunc_type, float g, float *w, float *wp)
+{
+	const float costheta = Inpf(w, wp);
+	const float scale = M_PI;
+	
+	/*
+	 * Scale constant is required, since Blender's shading system doesn't normalise for
+	 * energy conservation - eg. scaling by 1/pi for a lambert shader.
+	 * This makes volumes darker than other solid objects, for the same lighting intensity.
+	 * To correct this, scale up the phase function values
+	 * until Blender's shading system supports this better. --matt
+	 */
+	
+	switch (phasefunc_type) {
+		case MA_VOL_PH_MIEHAZY:
+			return scale * (0.5f + 4.5f * powf(0.5 * (1.f + costheta), 8.f)) / (4.f*M_PI);
+		case MA_VOL_PH_MIEMURKY:
+			return scale * (0.5f + 16.5f * powf(0.5 * (1.f + costheta), 32.f)) / (4.f*M_PI);
+		case MA_VOL_PH_RAYLEIGH:
+			return scale * 3.f/(16.f*M_PI) * (1 + costheta * costheta);
+		case MA_VOL_PH_HG:
+			return scale * (1.f / (4.f * M_PI) * (1.f - g*g) / powf(1.f + g*g - 2.f * g * costheta, 1.5f));
+		case MA_VOL_PH_SCHLICK:
+		{
+			const float k = 1.55f * g - .55f * g * g * g;
+			const float kcostheta = k * costheta;
+			return scale * (1.f / (4.f * M_PI) * (1.f - k*k) / ((1.f - kcostheta) * (1.f - kcostheta)));
+		}
+		case MA_VOL_PH_ISOTROPIC:
+		default:
+			return scale * (1.f / (4.f * M_PI));
+	}
+}
+
 /* Compute attenuation, otherwise known as 'optical thickness', extinction, or tau.
  * Used in the relationship Transmittance = e^(-attenuation)
  */
@@ -360,7 +369,7 @@ void vol_shade_one_lamp(struct ShadeInput *shi, float *co, LampRen *lar, float *
 		}
 	}
 	
-	vol_get_scattering_fac(shi, &scatter_fac, co, density);
+	scatter_fac = vol_get_scattering_fac(shi, co);
 	VecMulf(lacol, scatter_fac);
 }
 
@@ -371,16 +380,13 @@ void vol_get_scattering(ShadeInput *shi, float *scatter, float *co, float stepsi
 	GroupObject *go;
 	LampRen *lar;
 	float col[3] = {0.f, 0.f, 0.f};
-	int i=0;
-
+	
 	lights= get_lights(shi);
 	for(go=lights->first; go; go= go->next)
 	{
 		float lacol[3] = {0.f, 0.f, 0.f};
-	
-		i++;
-	
 		lar= go->lampren;
+		
 		if (lar) {
 			vol_shade_one_lamp(shi, co, lar, lacol, stepsize, density);
 			VecAddf(col, col, lacol);
@@ -575,9 +581,7 @@ static void volume_trace(struct ShadeInput *shi, struct ShadeResult *shr, int in
 		/* shade volume from 'camera' to 1st hit point */
 		volumeintegrate(shi, col, shi->camera_co, shi->co);
 		
-		shr->combined[0] = col[0];
-		shr->combined[1] = col[1];
-		shr->combined[2] = col[2];
+		VecCopyf(shr->combined, col);
 		
 		if (shi->mat->vol.shadeflag & MA_VOL_USEALPHA) {
 			if (col[3] > 1.0f)
@@ -606,9 +610,7 @@ static void volume_trace(struct ShadeInput *shi, struct ShadeResult *shr, int in
 		/* shade volume from 1st hit point to 2nd hit point */
 		volumeintegrate(shi, col, shi->co, hitco);
 		
-		shr->combined[0] = col[0];
-		shr->combined[1] = col[1];
-		shr->combined[2] = col[2];
+		VecCopyf(shr->combined, col);
 		
 		if (shi->mat->vol.shadeflag & MA_VOL_USEALPHA) {
 			if (col[3] > 1.0f)
@@ -650,9 +652,8 @@ void shade_volume_shadow(struct ShadeInput *shi, struct ShadeResult *shr, struct
 		tr[1] = exp(-tau[1]);
 		tr[2] = exp(-tau[2]);
 		
-		shr->combined[0] = tr[0];
-		shr->combined[1] = tr[1];
-		shr->combined[2] = tr[2];
+		
+		VecCopyf(shr->combined, tr);
 		
 		shr->combined[3] = 1.0f -(tr[0] + tr[1] + tr[2]) * 0.333f;
 		shr->alpha = shr->combined[3];
@@ -666,9 +667,7 @@ void shade_volume_shadow(struct ShadeInput *shi, struct ShadeResult *shr, struct
 		tr[1] = exp(-tau[1]);
 		tr[2] = exp(-tau[2]);
 		
-		shr->combined[0] = tr[0];
-		shr->combined[1] = tr[1];
-		shr->combined[2] = tr[2];
+		VecCopyf(shr->combined, tr);
 		
 		shr->combined[3] = 1.0f -(tr[0] + tr[1] + tr[2]) * 0.333f;
 		shr->alpha = shr->combined[3];