volumetric light updates

WickedEngine/shaders/upsample_bilateral_float4CS.hlsl

@@ -13,13 +13,15 @@ TEXTURE2D(input, UPSAMPLE_FORMAT, TEXSLOT_ONDEMAND0);
 // Run this post process as pixel shader:
 float4 main(float4 pos : SV_Position, float2 uv : TEXCOORD) : SV_TARGET
 {
+	const uint2 pixel = pos.xy;
 #else
 // Run this post process as compute shader:
 RWTEXTURE2D(output, UPSAMPLE_FORMAT, 0);
 [numthreads(POSTPROCESS_BLOCKSIZE, POSTPROCESS_BLOCKSIZE, 1)]
 void main(uint3 DTid : SV_DispatchThreadID)
 {
-	const float2 uv = (DTid.xy + 0.5f) * xPPResolution_rcp;
+	const uint2 pixel = DTid.xy;
+	const float2 uv = (pixel + 0.5f) * xPPResolution_rcp;
 #endif // USE_PIXELSHADER
 
 
@@ -28,12 +30,12 @@ void main(uint3 DTid : SV_DispatchThreadID)
 	const float2 lowres_size = xPPParams1.xy;
 	const float2 lowres_texel_size = xPPParams1.zw;
 
-	const float2 uv00 = uv - 0.5f * lowres_texel_size;
+	const float2 uv00 = uv - lowres_texel_size * 0.5;
 	const float2 uv10 = uv00 + float2(lowres_texel_size.x, 0);
 	const float2 uv01 = uv00 + float2(0, lowres_texel_size.y);
 	const float2 uv11 = uv00 + lowres_texel_size;
 
-	const float4 lineardepth_highres = texture_lineardepth.SampleLevel(sampler_point_clamp, uv, 0).xxxx;
+	const float4 lineardepth_highres = texture_lineardepth[pixel].xxxx;
 	const float4 lineardepth_lowres = float4(
 		texture_lineardepth.SampleLevel(sampler_point_clamp, uv00, lowres_depthchain_mip),
 		texture_lineardepth.SampleLevel(sampler_point_clamp, uv10, lowres_depthchain_mip),
@@ -58,7 +60,10 @@ void main(uint3 DTid : SV_DispatchThreadID)
 	}
 	else
 	{
-		// large error, find nearest sample to current depth:
+		// large error:
+
+#ifdef UPSAMPLE_DISABLE_FILTERING
+		// find nearest sample to current depth:
 		float min_depth_diff = depth_diff[0];
 		float2 uv_nearest = uv00;
 
@@ -79,11 +84,20 @@ void main(uint3 DTid : SV_DispatchThreadID)
 			uv_nearest = uv11;
 			min_depth_diff = depth_diff[3];
 		}
-
-#ifdef UPSAMPLE_DISABLE_FILTERING
 		color = input[floor(uv_nearest * lowres_size)];
 #else
-		color = input.SampleLevel(sampler_point_clamp, uv_nearest, 0);
+
+		// depth-weighted blending:
+		float4 weights = saturate(1 - abs(lineardepth_highres - lineardepth_lowres));
+		float sum = weights[0] + weights[1] + weights[2] + weights[3];
+		weights /= max(sum, 0.0001);
+
+		color = 0;
+		color += input.SampleLevel(sampler_point_clamp, uv00, 0) * weights[0];
+		color += input.SampleLevel(sampler_point_clamp, uv10, 0) * weights[1];
+		color += input.SampleLevel(sampler_point_clamp, uv01, 0) * weights[2];
+		color += input.SampleLevel(sampler_point_clamp, uv11, 0) * weights[3];
+
 #endif // UPSAMPLE_DISABLE_FILTERING
 	}
 

WickedEngine/shaders/volumetricLightHF.hlsli

@@ -9,5 +9,14 @@ struct VertexToPixel {
 	float4 pos2D		: POSITION2D;
 };
 
+// Mie scaterring approximated with Henyey-Greenstein phase function.
+//	https://www.alexandre-pestana.com/volumetric-lights/
+#define G_SCATTERING 0.66
+float ComputeScattering(float lightDotView)
+{
+	float result = 1.0f - G_SCATTERING * G_SCATTERING;
+	result /= (4.0f * PI * pow(1.0f + G_SCATTERING * G_SCATTERING - (2.0f * G_SCATTERING) * lightDotView, 1.5f));
+	return result;
+}
 
 #endif // WI_VOLUMETRICLIGHT_HF

WickedEngine/shaders/volumetricLight_DirectionalPS.hlsl

@@ -23,6 +23,7 @@ float4 main(VertexToPixel input) : SV_TARGET
 	float3 accumulation = 0;
 
 	const float3 L = light.GetDirection();
+	const float scattering = ComputeScattering(saturate(dot(L, -V)));
 
 	float3 rayEnd = g_xCamera_CamPos;
 
@@ -47,7 +48,7 @@ float4 main(VertexToPixel input) : SV_TARGET
 			{
 				float3 attenuation = shadowCascade(light, ShPos, ShTex.xy, cascade);
 
-				attenuation *= GetFogAmount(cameraDistance - marchedDistance);
+				attenuation *= GetFogAmount(cameraDistance - marchedDistance) * scattering;
 
 				accumulation += attenuation;
 
@@ -64,8 +65,13 @@ float4 main(VertexToPixel input) : SV_TARGET
 			break;
 		}
 	}
-
 	accumulation /= sampleCount;
 
-	return max(0, float4(accumulation * light.GetColor().rgb * light.GetEnergy(), 1));
+	float3 atmosphereTransmittance = 1;
+	if (g_xFrame_Options & OPTION_BIT_REALISTIC_SKY)
+	{
+		atmosphereTransmittance = GetAtmosphericLightTransmittance(g_xFrame_Atmosphere, P, L, texture_transmittancelut);
+	}
+
+	return max(0, float4(accumulation * light.GetColor().rgb * light.GetEnergy() * atmosphereTransmittance, 1));
 }

WickedEngine/wiRenderer.cpp

@@ -4508,6 +4508,10 @@ void DrawVolumeLights(
 		BindShadowmaps(PS, cmd);
 
 		device->BindResource(PS, &depthbuffer, TEXSLOT_DEPTH, cmd);
+		device->BindResource(PS, &textures[TEXTYPE_2D_SKYATMOSPHERE_SKYVIEWLUT], TEXSLOT_SKYVIEWLUT, cmd);
+		device->BindResource(PS, &textures[TEXTYPE_2D_SKYATMOSPHERE_TRANSMITTANCELUT], TEXSLOT_TRANSMITTANCELUT, cmd);
+		device->BindResource(PS, &textures[TEXTYPE_2D_SKYATMOSPHERE_MULTISCATTEREDLUMINANCELUT], TEXSLOT_MULTISCATTERINGLUT, cmd);
+		device->BindResource(PS, &textures[TEXTYPE_2D_SKYATMOSPHERE_SKYLUMINANCELUT], TEXSLOT_SKYLUMINANCELUT, cmd);
 
 		XMMATRIX VP = vis.camera->GetViewProjection();
 

WickedEngine/wiTextureHelper.cpp

@@ -41,7 +41,7 @@ namespace wiTextureHelper
 				data[i] = wiRandom::getRandom(0, 255);
 				data[i + 1] = wiRandom::getRandom(0, 255);
 				data[i + 2] = wiRandom::getRandom(0, 255);
-				data[i + 3] = 255;
+				data[i + 3] = wiRandom::getRandom(0, 255);
 			}
 
 			CreateTexture(helperTextures[HELPERTEXTURE_RANDOM64X64], data, 64, 64);

WickedEngine/wiVersion.cpp

@@ -9,7 +9,7 @@ namespace wiVersion
 	// minor features, major updates, breaking compatibility changes
 	const int minor = 56;
 	// minor bug fixes, alterations, refactors, updates
-	const int revision = 18;
+	const int revision = 19;
 
 	const std::string version_string = std::to_string(major) + "." + std::to_string(minor) + "." + std::to_string(revision);