From 19313d4635716306719193e769221c3e33bea5cd Mon Sep 17 00:00:00 2001
From: Alex Laptop <alexander.gauggel@web.de>
Date: Fri, 17 Sep 2021 15:19:14 +0200
Subject: [PATCH] [#114] Switch to newer MSM quantization scheme and reduce
moment blur radius from 9 to 7 pixels to reduce floating point precision
problems and make it work on iGPU
---
.../assets/shaders/depthToMoments.comp | 4 +-
.../assets/shaders/shadowBlur.inc | 2 +-
.../assets/shaders/shadowBlurX.comp | 2 +-
.../assets/shaders/shadowBlurY.comp | 6 +--
.../assets/shaders/shadowMapping.inc | 38 ++++++++++---------
5 files changed, 27 insertions(+), 25 deletions(-)
diff --git a/projects/voxelization/assets/shaders/depthToMoments.comp b/projects/voxelization/assets/shaders/depthToMoments.comp
index 5a78d0cb..79e47cde 100644
--- a/projects/voxelization/assets/shaders/depthToMoments.comp
+++ b/projects/voxelization/assets/shaders/depthToMoments.comp
@@ -28,9 +28,11 @@ void main(){
z += texelFetch(sampler2DMS(srcTexture, depthSampler), uv, i).r;
}
z /= msaaCount;
-
+ z = 2 * z - 1; // algorithm expects depth in range [-1:1]
+
float z2 = z*z;
vec4 moments = vec4(z, z2, z2*z, z2*z2);
vec4 momentsQuantized = quantizeMoments(moments);
+
imageStore(outImage, uv, momentsQuantized);
}
\ No newline at end of file
diff --git a/projects/voxelization/assets/shaders/shadowBlur.inc b/projects/voxelization/assets/shaders/shadowBlur.inc
index 06147415..ed4994ed 100644
--- a/projects/voxelization/assets/shaders/shadowBlur.inc
+++ b/projects/voxelization/assets/shaders/shadowBlur.inc
@@ -3,7 +3,7 @@
vec4 blurMomentShadowMap1D(ivec2 coord, ivec2 blurDirection, texture2D srcTexture, sampler depthSampler){
- int blurRadius = 9;
+ int blurRadius = 7;
int minOffset = -(blurRadius-1) / 2;
int maxOffset = -minOffset;
diff --git a/projects/voxelization/assets/shaders/shadowBlurX.comp b/projects/voxelization/assets/shaders/shadowBlurX.comp
index 45b91aad..41d127fd 100644
--- a/projects/voxelization/assets/shaders/shadowBlurX.comp
+++ b/projects/voxelization/assets/shaders/shadowBlurX.comp
@@ -18,6 +18,6 @@ void main(){
}
ivec2 coord = ivec2(gl_GlobalInvocationID.xy);
vec4 moments = blurMomentShadowMap1D(coord, ivec2(1, 0), srcTexture, depthSampler);
-
+ // moments = texelFetch(sampler2D(srcTexture, depthSampler), coord, 0);
imageStore(outImage, coord, moments);
}
\ No newline at end of file
diff --git a/projects/voxelization/assets/shaders/shadowBlurY.comp b/projects/voxelization/assets/shaders/shadowBlurY.comp
index 51d4df05..c1710d7d 100644
--- a/projects/voxelization/assets/shaders/shadowBlurY.comp
+++ b/projects/voxelization/assets/shaders/shadowBlurY.comp
@@ -16,10 +16,8 @@ void main(){
if(any(greaterThanEqual(gl_GlobalInvocationID.xy, imageSize(outImage)))){
return;
}
- ivec2 coord = ivec2(gl_GlobalInvocationID.xy);
- vec2 pixelSize = vec2(1) / textureSize(sampler2D(srcTexture, depthSampler), 0);
-
+ ivec2 coord = ivec2(gl_GlobalInvocationID.xy);
vec4 moments = blurMomentShadowMap1D(coord, ivec2(0, 1), srcTexture, depthSampler);
-
+ // moments = texelFetch(sampler2D(srcTexture, depthSampler), coord, 0);
imageStore(outImage, coord, moments);
}
\ No newline at end of file
diff --git a/projects/voxelization/assets/shaders/shadowMapping.inc b/projects/voxelization/assets/shaders/shadowMapping.inc
index c56ae898..9d65a2d3 100644
--- a/projects/voxelization/assets/shaders/shadowMapping.inc
+++ b/projects/voxelization/assets/shaders/shadowMapping.inc
@@ -6,7 +6,8 @@
// nice math blob from the moment shadow mapping presentation
float ComputeMSMShadowIntensity(vec4 _4Moments, float FragmentDepth, float DepthBias, float MomentBias)
{
- vec4 b=mix(_4Moments, vec4(0.5),MomentBias);
+ vec4 b=mix(_4Moments, vec4(0, 0.63, 0, 0.63),MomentBias);
+
vec3 z;
z[0]=FragmentDepth-DepthBias;
float L32D22=fma(-b[0], b[1], b[2]);
@@ -39,24 +40,23 @@ float ComputeMSMShadowIntensity(vec4 _4Moments, float FragmentDepth, float Depth
}
vec4 quantizeMoments(vec4 moments){
- mat4 T = mat4(
- -2.07224649, 13.7948857237, 0.105877704, 9.7924062118,
- 32.23703778, -59.4683975703, -1.9077466311, -33.7652110555,
- -68.571074599, 82.0359750338, 9.3496555107, 47.9456096605,
- 39.3703274134, -35.364903257, -6.6543490743, -23.9728048165);
- vec4 quantized = T * moments;
- quantized[0] += 0.0359558848;
- return quantized;
+ vec4 quantized;
+ quantized.r = 1.5 * moments.r - 2 * moments.b + 0.5;
+ quantized.g = 4 * moments.g - 4 * moments.a;
+ quantized.b = sqrt(3)/2 * moments.r - sqrt(12)/9 * moments.b + 0.5;
+ quantized.a = 0.5 * moments.g + 0.5 * moments.a;
+
+ return quantized;
}
vec4 unquantizeMoments(vec4 moments){
- moments[0] -= 0.0359558848;
- mat4 T = mat4(
- 0.2227744146, 0.1549679261, 0.1451988946, 0.163127443,
- 0.0771972861, 0.1394629426, 0.2120202157, 0.2591432266,
- 0.7926986636, 0.7963415838, 0.7258694464, 0.6539092497,
- 0.0319417555, -0.1722823173, -0.2758014811, -0.3376131734);
- return T * moments;
+ moments -= vec4(0.5, 0, 0.5, 0);
+ vec4 unquantized;
+ unquantized.r = -1.f / 3 * moments.r + sqrt(3) * moments.b;
+ unquantized.g = 0.125 * moments.g + moments.a;
+ unquantized.b = -0.75 * moments.r + 0.75 * sqrt(3) * moments.b;
+ unquantized.a = -0.125 * moments.g + moments.a;
+ return unquantized * 0.98;
}
float rescaleRange(float a, float b, float v)
@@ -78,17 +78,19 @@ float shadowTest(vec3 worldPos, LightInfo lightInfo, texture2D shadowMap, sample
if(any(lessThan(lightPos.xy, vec2(0))) || any(greaterThan(lightPos.xy, vec2(1)))){
return 1;
}
-
+
lightPos.z = clamp(lightPos.z, 0, 1);
+ lightPos.z = 2 * lightPos.z - 1; // algorithm expects depth in range [-1:1]
vec4 shadowMapSample = texture(sampler2D(shadowMap, shadowMapSampler), lightPos.xy);
shadowMapSample = unquantizeMoments(shadowMapSample);
float depthBias = 0.f;
- float momentBias = 0.0003;
+ float momentBias = 0.0006;
float shadow = ComputeMSMShadowIntensity(shadowMapSample, lightPos.z, depthBias, momentBias);
+ return clamp(shadow, 0, 1);
return reduceLightBleeding(shadow, 0.1f);
}
--
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