diff --git a/Source/Shaders/ShadowsSampling.hlsl b/Source/Shaders/ShadowsSampling.hlsl index 6d9390570..354e5065e 100644 --- a/Source/Shaders/ShadowsSampling.hlsl +++ b/Source/Shaders/ShadowsSampling.hlsl @@ -54,9 +54,7 @@ float2 GetLightShadowAtlasUV(ShadowData shadow, ShadowTileData shadowTile, float float SampleShadowMap(Texture2D shadowMap, float2 shadowMapUV, float sceneDepth) { - // Single hardware sample with filtering float result = SAMPLE_SHADOW_MAP(shadowMap, shadowMapUV, sceneDepth); - #if SHADOWS_QUALITY == 1 result += SAMPLE_SHADOW_MAP_OFFSET(shadowMap, shadowMapUV, int2(-1, 0), sceneDepth); result += SAMPLE_SHADOW_MAP_OFFSET(shadowMap, shadowMapUV, int2(0, -1), sceneDepth); @@ -64,7 +62,6 @@ float SampleShadowMap(Texture2D shadowMap, float2 shadowMapUV, float scen result += SAMPLE_SHADOW_MAP_OFFSET(shadowMap, shadowMapUV, int2(1, 0), sceneDepth); result = result * (1.0f / 4.0); #elif SHADOWS_QUALITY == 2 || SHADOWS_QUALITY == 3 - // TODO: implement Percentage-Closer Soft Shadows (PCSS) for Ultra quality result += SAMPLE_SHADOW_MAP_OFFSET(shadowMap, shadowMapUV, int2(-1, -1), sceneDepth); result += SAMPLE_SHADOW_MAP_OFFSET(shadowMap, shadowMapUV, int2(-1, 0), sceneDepth); result += SAMPLE_SHADOW_MAP_OFFSET(shadowMap, shadowMapUV, int2(-1, 1), sceneDepth); @@ -75,10 +72,133 @@ float SampleShadowMap(Texture2D shadowMap, float2 shadowMapUV, float scen result += SAMPLE_SHADOW_MAP_OFFSET(shadowMap, shadowMapUV, int2(1, 1), sceneDepth); result = result * (1.0f / 9.0); #endif - return result; } +float SampleShadowMapOptimizedPCFHelper(Texture2D shadowMap, float2 baseUV, float u, float v, float2 shadowMapSizeInv, float sceneDepth) +{ + float2 uv = baseUV + float2(u, v) * shadowMapSizeInv; + return SAMPLE_SHADOW_MAP(shadowMap, uv, sceneDepth); +} + +// [Shadow map sampling method used in The Witness, https://github.com/TheRealMJP/Shadows] +float SampleShadowMapOptimizedPCF(Texture2D shadowMap, float2 shadowMapUV, float sceneDepth) +{ +#if SHADOWS_QUALITY != 0 + float2 shadowMapSize; + shadowMap.GetDimensions(shadowMapSize.x, shadowMapSize.y); + + float2 uv = shadowMapUV.xy * shadowMapSize; // 1 unit - 1 texel + float2 shadowMapSizeInv = 1.0f / shadowMapSize; + + float2 baseUV; + baseUV.x = floor(uv.x + 0.5); + baseUV.y = floor(uv.y + 0.5); + float s = (uv.x + 0.5 - baseUV.x); + float t = (uv.y + 0.5 - baseUV.y); + baseUV -= float2(0.5, 0.5); + baseUV *= shadowMapSizeInv; + + float sum = 0; +#endif +#if SHADOWS_QUALITY == 0 + return SAMPLE_SHADOW_MAP(shadowMap, shadowMapUV, sceneDepth); +#elif SHADOWS_QUALITY == 1 + float uw0 = (3 - 2 * s); + float uw1 = (1 + 2 * s); + + float u0 = (2 - s) / uw0 - 1; + float u1 = s / uw1 + 1; + + float vw0 = (3 - 2 * t); + float vw1 = (1 + 2 * t); + + float v0 = (2 - t) / vw0 - 1; + float v1 = t / vw1 + 1; + + sum += uw0 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v0, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v0, shadowMapSizeInv, sceneDepth); + sum += uw0 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v1, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v1, shadowMapSizeInv, sceneDepth); + + return sum * 1.0f / 16; +#elif SHADOWS_QUALITY == 2 + float uw0 = (4 - 3 * s); + float uw1 = 7; + float uw2 = (1 + 3 * s); + + float u0 = (3 - 2 * s) / uw0 - 2; + float u1 = (3 + s) / uw1; + float u2 = s / uw2 + 2; + + float vw0 = (4 - 3 * t); + float vw1 = 7; + float vw2 = (1 + 3 * t); + + float v0 = (3 - 2 * t) / vw0 - 2; + float v1 = (3 + t) / vw1; + float v2 = t / vw2 + 2; + + sum += uw0 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v0, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v0, shadowMapSizeInv, sceneDepth); + sum += uw2 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u2, v0, shadowMapSizeInv, sceneDepth); + + sum += uw0 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v1, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v1, shadowMapSizeInv, sceneDepth); + sum += uw2 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u2, v1, shadowMapSizeInv, sceneDepth); + + sum += uw0 * vw2 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v2, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw2 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v2, shadowMapSizeInv, sceneDepth); + sum += uw2 * vw2 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u2, v2, shadowMapSizeInv, sceneDepth); + + return sum * 1.0f / 144; +#elif SHADOWS_QUALITY == 3 + float uw0 = (5 * s - 6); + float uw1 = (11 * s - 28); + float uw2 = -(11 * s + 17); + float uw3 = -(5 * s + 1); + + float u0 = (4 * s - 5) / uw0 - 3; + float u1 = (4 * s - 16) / uw1 - 1; + float u2 = -(7 * s + 5) / uw2 + 1; + float u3 = -s / uw3 + 3; + + float vw0 = (5 * t - 6); + float vw1 = (11 * t - 28); + float vw2 = -(11 * t + 17); + float vw3 = -(5 * t + 1); + + float v0 = (4 * t - 5) / vw0 - 3; + float v1 = (4 * t - 16) / vw1 - 1; + float v2 = -(7 * t + 5) / vw2 + 1; + float v3 = -t / vw3 + 3; + + sum += uw0 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v0, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v0, shadowMapSizeInv, sceneDepth); + sum += uw2 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u2, v0, shadowMapSizeInv, sceneDepth); + sum += uw3 * vw0 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u3, v0, shadowMapSizeInv, sceneDepth); + + sum += uw0 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v1, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v1, shadowMapSizeInv, sceneDepth); + sum += uw2 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u2, v1, shadowMapSizeInv, sceneDepth); + sum += uw3 * vw1 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u3, v1, shadowMapSizeInv, sceneDepth); + + sum += uw0 * vw2 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v2, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw2 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v2, shadowMapSizeInv, sceneDepth); + sum += uw2 * vw2 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u2, v2, shadowMapSizeInv, sceneDepth); + sum += uw3 * vw2 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u3, v2, shadowMapSizeInv, sceneDepth); + + sum += uw0 * vw3 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u0, v3, shadowMapSizeInv, sceneDepth); + sum += uw1 * vw3 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u1, v3, shadowMapSizeInv, sceneDepth); + sum += uw2 * vw3 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u2, v3, shadowMapSizeInv, sceneDepth); + sum += uw3 * vw3 * SampleShadowMapOptimizedPCFHelper(shadowMap, baseUV, u3, v3, shadowMapSizeInv, sceneDepth); + + return sum * (1.0f / 2704); +#else + return 0.0f; +#endif +} + // Samples the shadow for the given directional light on the material surface (supports subsurface shadowing) ShadowSample SampleDirectionalLightShadow(LightData light, Buffer shadowsBuffer, Texture2D shadowMap, GBufferSample gBuffer, float dither = 0.0f) { @@ -143,7 +263,7 @@ ShadowSample SampleDirectionalLightShadow(LightData light, Buffer shadow float2 shadowMapUV = GetLightShadowAtlasUV(shadow, shadowTile, samplePosition, shadowPosition); // Sample shadow map - result.SurfaceShadow = SampleShadowMap(shadowMap, shadowMapUV, shadowPosition.z); + result.SurfaceShadow = SampleShadowMapOptimizedPCF(shadowMap, shadowMapUV, shadowPosition.z); // Increase the sharpness for higher cascades to match the filter radius //const float SharpnessScale[MaxNumCascades] = { 1.0f, 1.5f, 3.0f, 3.5f }; @@ -207,7 +327,7 @@ ShadowSample SampleLocalLightShadow(LightData light, Buffer shadowsBuffe float2 shadowMapUV = GetLightShadowAtlasUV(shadow, shadowTile, samplePosition, shadowPosition); // Sample shadow map - result.SurfaceShadow = SampleShadowMap(shadowMap, shadowMapUV, shadowPosition.z); + result.SurfaceShadow = SampleShadowMapOptimizedPCF(shadowMap, shadowMapUV, shadowPosition.z); #if defined(USE_GBUFFER_CUSTOM_DATA) // Subsurface shadowing