From 47c794626fb0f8a5f1d424e9e9b55803a060d4c9 Mon Sep 17 00:00:00 2001
From: Alexander Gauggel <agauggel@uni-koblenz.de>
Date: Wed, 18 Aug 2021 17:12:31 +0200
Subject: [PATCH] [#106] Add jitter to motion tile lookup in motion blur to
replace hard edges in blur with noise
---
.../resources/shaders/motionBlur.comp | 21 ++++++++++++++++++-
projects/indirect_dispatch/src/App.cpp | 7 +++++--
projects/indirect_dispatch/src/MotionBlur.cpp | 11 ++++++----
projects/indirect_dispatch/src/MotionBlur.hpp | 3 ++-
4 files changed, 34 insertions(+), 8 deletions(-)
diff --git a/projects/indirect_dispatch/resources/shaders/motionBlur.comp b/projects/indirect_dispatch/resources/shaders/motionBlur.comp
index 43981689..d340d4d4 100644
--- a/projects/indirect_dispatch/resources/shaders/motionBlur.comp
+++ b/projects/indirect_dispatch/resources/shaders/motionBlur.comp
@@ -17,6 +17,7 @@ layout( push_constant ) uniform constants{
// camera planes are needed to linearize depth
float cameraNearPlane;
float cameraFarPlane;
+ float motionTileOffsetLength;
};
float linearizeDepth(float depth, float near, float far){
@@ -111,6 +112,22 @@ float dither(ivec2 coord){
return x ^^ y ? 1 : 0;
}
+// from https://www.shadertoy.com/view/ttc3zr
+uvec2 murmurHash22(uvec2 src) {
+ const uint M = 0x5bd1e995u;
+ uvec2 h = uvec2(1190494759u, 2147483647u);
+ src *= M; src ^= src>>24u; src *= M;
+ h *= M; h ^= src.x; h *= M; h ^= src.y;
+ h ^= h>>13u; h *= M; h ^= h>>15u;
+ return h;
+}
+
+vec2 hash22(vec2 src) {
+ uvec2 h = murmurHash22(floatBitsToUint(src));
+ return uintBitsToFloat(h & 0x007fffffu | 0x3f800000u) - 1.0;
+}
+
+
void main(){
if(any(greaterThanEqual(gl_GlobalInvocationID.xy, imageSize(outImage))))
@@ -120,7 +137,9 @@ void main(){
ivec2 coord = ivec2(gl_GlobalInvocationID.xy);
vec2 uv = vec2(coord + 0.5) / textureRes; // + 0.5 to shift uv into pixel center
- vec2 motionNeighbourhoodMax = processMotionVector(texture(sampler2D(inMotionNeighbourhoodMax, nearestSampler), uv).rg);
+ // the motion tile lookup is jittered, so the hard edges in the blur are replaced by noise
+ vec2 motionOffset = motionTileOffsetLength * (hash22(coord) * 2 - 1) / textureRes;
+ vec2 motionNeighbourhoodMax = processMotionVector(texture(sampler2D(inMotionNeighbourhoodMax, nearestSampler), uv + motionOffset).rg);
SampleData mainPixel = loadSampleData(uv);
diff --git a/projects/indirect_dispatch/src/App.cpp b/projects/indirect_dispatch/src/App.cpp
index db97d57c..ecdbd50e 100644
--- a/projects/indirect_dispatch/src/App.cpp
+++ b/projects/indirect_dispatch/src/App.cpp
@@ -96,7 +96,8 @@ void App::run() {
eMotionVectorVisualisationMode motionVectorVisualisationMode = eMotionVectorVisualisationMode::None;
eMotionVectorMode motionBlurMotionMode = eMotionVectorMode::MaxTileNeighbourhood;
- bool freezeFrame = false;
+ bool freezeFrame = false;
+ float motionBlurTileOffsetLength = 10;
float objectVerticalSpeed = 5;
float objectAmplitude = 0;
float objectMeanHeight = 1;
@@ -276,7 +277,8 @@ void App::run() {
cameraNear,
cameraFar,
fDeltaTimeSeconds,
- cameraShutterSpeedInverse);
+ cameraShutterSpeedInverse,
+ motionBlurTileOffsetLength);
}
else {
eMotionVectorMode debugViewMode;
@@ -331,6 +333,7 @@ void App::run() {
ImGui::Begin("Settings");
ImGui::Checkbox("Freeze frame", &freezeFrame);
+ ImGui::InputFloat("Motion tile offset length", &motionBlurTileOffsetLength);
ImGui::Combo(
"Debug view",
diff --git a/projects/indirect_dispatch/src/MotionBlur.cpp b/projects/indirect_dispatch/src/MotionBlur.cpp
index a731b8b9..49e8b288 100644
--- a/projects/indirect_dispatch/src/MotionBlur.cpp
+++ b/projects/indirect_dispatch/src/MotionBlur.cpp
@@ -58,7 +58,8 @@ vkcv::ImageHandle MotionBlur::render(
const float cameraNear,
const float cameraFar,
const float deltaTimeSeconds,
- const float cameraShutterSpeedInverse) {
+ const float cameraShutterSpeedInverse,
+ const float motionTileOffsetLength) {
computeMotionTiles(cmdStream, motionBufferFullRes);
@@ -93,14 +94,16 @@ vkcv::ImageHandle MotionBlur::render(
float motionFactor;
float cameraNearPlane;
float cameraFarPlane;
+ float motionTileOffsetLength;
};
MotionBlurConstantData motionBlurConstantData;
const float deltaTimeMotionBlur = deltaTimeSeconds;
- motionBlurConstantData.motionFactor = 1 / (deltaTimeMotionBlur * cameraShutterSpeedInverse);
- motionBlurConstantData.cameraNearPlane = cameraNear;
- motionBlurConstantData.cameraFarPlane = cameraFar;
+ motionBlurConstantData.motionFactor = 1 / (deltaTimeMotionBlur * cameraShutterSpeedInverse);
+ motionBlurConstantData.cameraNearPlane = cameraNear;
+ motionBlurConstantData.cameraFarPlane = cameraFar;
+ motionBlurConstantData.motionTileOffsetLength = motionTileOffsetLength;
vkcv::PushConstants motionBlurPushConstants(sizeof(motionBlurConstantData));
motionBlurPushConstants.appendDrawcall(motionBlurConstantData);
diff --git a/projects/indirect_dispatch/src/MotionBlur.hpp b/projects/indirect_dispatch/src/MotionBlur.hpp
index a6232125..b90cdfa4 100644
--- a/projects/indirect_dispatch/src/MotionBlur.hpp
+++ b/projects/indirect_dispatch/src/MotionBlur.hpp
@@ -31,7 +31,8 @@ public:
const float cameraNear,
const float cameraFar,
const float deltaTimeSeconds,
- const float cameraShutterSpeedInverse);
+ const float cameraShutterSpeedInverse,
+ const float motionTileOffsetLength);
vkcv::ImageHandle renderMotionVectorVisualisation(
const vkcv::CommandStreamHandle cmdStream,
--
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