From 07f23c39a5ec7143f559cdba4a56920dc4bc7def Mon Sep 17 00:00:00 2001
From: Alexander Gauggel <agauggel@uni-koblenz.de>
Date: Wed, 23 Jun 2021 10:31:07 +0200
Subject: [PATCH] [#82] EVSM prototype
---
.../resources/shaders/lightInfo.inc | 2 +-
.../resources/shaders/shadow.frag | 7 ++--
.../resources/shaders/shadowMapping.inc | 41 +++++++++++++++++--
projects/voxelization/src/ShadowMapping.cpp | 8 ++--
projects/voxelization/src/ShadowMapping.hpp | 4 +-
projects/voxelization/src/main.cpp | 17 ++++----
6 files changed, 60 insertions(+), 19 deletions(-)
diff --git a/projects/voxelization/resources/shaders/lightInfo.inc b/projects/voxelization/resources/shaders/lightInfo.inc
index ed7f8d8b..c0df6551 100644
--- a/projects/voxelization/resources/shaders/lightInfo.inc
+++ b/projects/voxelization/resources/shaders/lightInfo.inc
@@ -6,7 +6,7 @@ struct LightInfo{
vec3 sunColor;
float sunStrength;
mat4 lightMatrix;
- float exponentialWarp;
+ vec2 warps;
};
#endif // #ifndef LIGHT_INFO_INC
\ No newline at end of file
diff --git a/projects/voxelization/resources/shaders/shadow.frag b/projects/voxelization/resources/shaders/shadow.frag
index a0bc121d..83500f94 100644
--- a/projects/voxelization/resources/shaders/shadow.frag
+++ b/projects/voxelization/resources/shaders/shadow.frag
@@ -8,11 +8,12 @@ layout(set=0, binding=0) uniform LightInfoBuffer {
LightInfo lightInfo;
};
-layout(location = 0) out float outExponentialDepth;
+layout(location = 0) out vec4 outMoments;
layout(location = 0) in vec4 passPos;
void main() {
- float z = passPos.z / passPos.w;
- outExponentialDepth = exp(z * lightInfo.exponentialWarp);
+ float z = passPos.z / passPos.w;
+ vec2 zWarped = applyDepthWarp(z, lightInfo.warps);
+ outMoments = vec4(zWarped, zWarped*zWarped);
}
\ No newline at end of file
diff --git a/projects/voxelization/resources/shaders/shadowMapping.inc b/projects/voxelization/resources/shaders/shadowMapping.inc
index e0a218d5..91461c91 100644
--- a/projects/voxelization/resources/shaders/shadowMapping.inc
+++ b/projects/voxelization/resources/shaders/shadowMapping.inc
@@ -3,6 +3,32 @@
#include "lightInfo.inc"
+vec2 applyDepthWarp(float z, vec2 warp){
+ z = 2 * z - 1;
+ float positive = exp( z * warp.x);
+ float negative = -exp(-z * warp.y);
+ return vec2(positive, negative);
+}
+
+float rescale(float a, float b, float v)
+{
+ return clamp((v - a) / (b - a), 0, 1);
+}
+
+float reduceVSMBleeding(float shadowValue, float newMin)
+{
+ return rescale(newMin, 1.0f, shadowValue);
+}
+
+float chebyshevInequality(float mean, float meanSquare, float sampleIn){
+ float variance = meanSquare - mean * mean;
+ float d = sampleIn - mean;
+ float pMax = clamp(variance / (variance + d*d), 0, 1);
+ pMax = reduceVSMBleeding(pMax, 0.1);
+
+ return pMax;
+}
+
float shadowTest(vec3 worldPos, LightInfo lightInfo, texture2D shadowMap, sampler shadowMapSampler){
vec4 lightPos = lightInfo.lightMatrix * vec4(worldPos, 1);
lightPos /= lightPos.w;
@@ -12,11 +38,18 @@ float shadowTest(vec3 worldPos, LightInfo lightInfo, texture2D shadowMap, sample
return 1;
}
- lightPos.z = clamp(lightPos.z, 0, 1);
+ lightPos.z = clamp(lightPos.z, 0, 1);
+ vec2 warpedSample = applyDepthWarp(lightPos.z, lightInfo.warps);
- // using exponential shadow mapping
- float shadowMapSample = texture(sampler2D(shadowMap, shadowMapSampler), lightPos.xy).r;
- return clamp(exp(-lightInfo.exponentialWarp * lightPos.z) * shadowMapSample, 0, 1);
+ // using exponential variance shadow mapping
+ vec4 shadowMapSample = texture(sampler2D(shadowMap, shadowMapSampler), lightPos.xy);
+ vec2 positiveMoments = shadowMapSample.rb;
+ vec2 negativeMoments = shadowMapSample.ga;
+
+ float s1 = chebyshevInequality(positiveMoments.r, positiveMoments.g, warpedSample.x);
+ float s2 = chebyshevInequality(negativeMoments.r, negativeMoments.g, warpedSample.y);
+
+ return min(s1, s2);
}
#endif // #ifndef SHADOW_MAPPING_INC
\ No newline at end of file
diff --git a/projects/voxelization/src/ShadowMapping.cpp b/projects/voxelization/src/ShadowMapping.cpp
index 456ef2cd..83ce118a 100644
--- a/projects/voxelization/src/ShadowMapping.cpp
+++ b/projects/voxelization/src/ShadowMapping.cpp
@@ -103,7 +103,7 @@ glm::mat4 computeShadowViewProjectionMatrix(
return vulkanCorrectionMatrix * crop * view;
}
-const vk::Format shadowMapFormat = vk::Format::eR32Sfloat;
+const vk::Format shadowMapFormat = vk::Format::eR32G32B32A32Sfloat;
const vk::Format shadowMapDepthFormat = vk::Format::eD16Unorm;
const uint32_t shadowMapResolution = 2048;
@@ -156,7 +156,8 @@ void ShadowMapping::recordShadowMapRendering(
const glm::vec3& lightColor,
float lightStrength,
float maxShadowDistance,
- float exponentialWarp,
+ float exponentialWarpPositive,
+ float exponentialWarpNegative,
const std::vector<vkcv::Mesh>& meshes,
const std::vector<glm::mat4>& modelMatrices,
const vkcv::camera::Camera& camera,
@@ -170,7 +171,8 @@ void ShadowMapping::recordShadowMapRendering(
std::cos(lightAngleRadian.x) * std::cos(lightAngleRadian.y),
std::sin(lightAngleRadian.x),
std::cos(lightAngleRadian.x) * std::sin(lightAngleRadian.y)));
- lightInfo.exponentialWarp = exponentialWarp;
+ lightInfo.exponentialWarpPositive = exponentialWarpPositive;
+ lightInfo.exponentialWarpNegative = exponentialWarpNegative;
lightInfo.lightMatrix = computeShadowViewProjectionMatrix(
lightInfo.direction,
diff --git a/projects/voxelization/src/ShadowMapping.hpp b/projects/voxelization/src/ShadowMapping.hpp
index d72ca06c..541ad383 100644
--- a/projects/voxelization/src/ShadowMapping.hpp
+++ b/projects/voxelization/src/ShadowMapping.hpp
@@ -13,7 +13,8 @@ struct LightInfo {
glm::vec3 sunColor;
float sunStrength;
glm::mat4 lightMatrix;
- float exponentialWarp;
+ float exponentialWarpPositive;
+ float exponentialWarpNegative;
};
class ShadowMapping {
@@ -27,6 +28,7 @@ public:
float lightStrength,
float maxShadowDistance,
float exponentialWarp,
+ float exponentialWarpNegative,
const std::vector<vkcv::Mesh>& meshes,
const std::vector<glm::mat4>& modelMatrices,
const vkcv::camera::Camera& camera,
diff --git a/projects/voxelization/src/main.cpp b/projects/voxelization/src/main.cpp
index a56113d0..b488426d 100644
--- a/projects/voxelization/src/main.cpp
+++ b/projects/voxelization/src/main.cpp
@@ -325,11 +325,12 @@ int main(int argc, const char** argv) {
vkcv::gui::GUI gui(core, window);
- glm::vec2 lightAnglesDegree = glm::vec2(90.f, 0.f);
- glm::vec3 lightColor = glm::vec3(1);
- float lightStrength = 25.f;
- float maxShadowDistance = 30.f;
- float shadowExponentialWarp = 60.f;
+ glm::vec2 lightAnglesDegree = glm::vec2(90.f, 0.f);
+ glm::vec3 lightColor = glm::vec3(1);
+ float lightStrength = 25.f;
+ float maxShadowDistance = 30.f;
+ float shadowExponentialWarpPositive = 60.f;
+ float shadowExponentialWarpNegative = 60.f;
int voxelVisualisationMip = 0;
float voxelizationExtent = 30.f;
@@ -378,7 +379,8 @@ int main(int argc, const char** argv) {
lightColor,
lightStrength,
maxShadowDistance,
- shadowExponentialWarp,
+ shadowExponentialWarpPositive,
+ shadowExponentialWarpNegative,
meshes,
modelMatrices,
cameraManager.getActiveCamera(),
@@ -446,7 +448,8 @@ int main(int argc, const char** argv) {
ImGui::DragFloat("Sun strength", &lightStrength);
ImGui::DragFloat("Max shadow distance", &maxShadowDistance);
maxShadowDistance = std::max(maxShadowDistance, 1.f);
- ImGui::DragFloat("Shadow exponential warp", &shadowExponentialWarp);
+ ImGui::DragFloat("Shadow exponential warp positive", &shadowExponentialWarpPositive);
+ ImGui::DragFloat("Shadow exponential warp negative", &shadowExponentialWarpNegative);
ImGui::Checkbox("Draw voxel visualisation", &renderVoxelVis);
ImGui::SliderInt("Visualisation mip", &voxelVisualisationMip, 0, 7);
--
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