From d6752ceb3ca7b05c384f3c330dddf73bb41bdb56 Mon Sep 17 00:00:00 2001
From: Tobias Frisch <tfrisch@uni-koblenz.de>
Date: Mon, 31 Jan 2022 01:14:04 +0100
Subject: [PATCH] Adjusted shaders to fix deformation
Signed-off-by: Tobias Frisch <tfrisch@uni-koblenz.de>
---
projects/wobble_bobble/shaders/grid.frag | 2 +-
projects/wobble_bobble/shaders/particle.inc | 18 ++++----
.../shaders/transform_particles_to_grid.comp | 11 ++++-
.../shaders/update_grid_forces.comp | 42 ++++++++++-------
.../shaders/update_particle_deformation.comp | 46 +++++++++++++------
.../shaders/update_particle_velocities.comp | 11 +++--
projects/wobble_bobble/src/main.cpp | 30 ++++++++++--
7 files changed, 109 insertions(+), 51 deletions(-)
diff --git a/projects/wobble_bobble/shaders/grid.frag b/projects/wobble_bobble/shaders/grid.frag
index 00c405d1..c3dc1fb2 100644
--- a/projects/wobble_bobble/shaders/grid.frag
+++ b/projects/wobble_bobble/shaders/grid.frag
@@ -19,7 +19,7 @@ void main() {
vec3 surface = vec3(passPos.x + 0.5f, passPos.y + 0.5f, z * 2.0f);
vec3 velocity = vec3(0.5f) + 0.5f * normalize(passVelocity.xyz);
- outColor = surface;
+ outColor = velocity;
} else {
discard;
}
diff --git a/projects/wobble_bobble/shaders/particle.inc b/projects/wobble_bobble/shaders/particle.inc
index 6ce314ab..ae584f1a 100644
--- a/projects/wobble_bobble/shaders/particle.inc
+++ b/projects/wobble_bobble/shaders/particle.inc
@@ -41,14 +41,14 @@ float weight_C(float x) {
}
}
-float voxel_particle_weight(vec3 voxel, ParticleMinimal particle) {
+vec3 voxel_particle_weight(vec3 voxel, ParticleMinimal particle) {
if (particle.size <= 0.0f) {
- return 0.0f;
+ return vec3(0.0f);
}
vec3 delta = abs(particle.position - voxel) / particle.size;
- return weight_C(delta.x) * weight_C(delta.y) * weight_C(delta.z);
+ return vec3(weight_C(delta.x), weight_C(delta.y), weight_C(delta.z));
}
float grad_weight_A(float x) {
@@ -78,9 +78,9 @@ float grad_weight_C(float x) {
}
}
-float voxel_particle_grad_weight(vec3 voxel, ParticleMinimal particle) {
+vec3 voxel_particle_grad_weight(vec3 voxel, ParticleMinimal particle) {
if (particle.size <= 0.0f) {
- return 0.0f;
+ return vec3(0.0f);
}
vec3 sign_delta = (particle.position - voxel) / particle.size;
@@ -88,12 +88,12 @@ float voxel_particle_grad_weight(vec3 voxel, ParticleMinimal particle) {
vec3 sign = sign(sign_delta);
vec3 weight = vec3(
- weight_C(delta.x),
- weight_C(delta.y),
- weight_C(delta.z)
+ grad_weight_C(delta.x),
+ grad_weight_C(delta.y),
+ grad_weight_C(delta.z)
);
- return dot(weight, sign);
+ return weight * sign;
}
#endif // PARTICLE_INC
\ No newline at end of file
diff --git a/projects/wobble_bobble/shaders/transform_particles_to_grid.comp b/projects/wobble_bobble/shaders/transform_particles_to_grid.comp
index bfd902b5..d582986d 100644
--- a/projects/wobble_bobble/shaders/transform_particles_to_grid.comp
+++ b/projects/wobble_bobble/shaders/transform_particles_to_grid.comp
@@ -10,6 +10,7 @@ layout(set=0, binding=0, std430) buffer particleBuffer {
};
layout(set=0, binding=1, rgba32f) restrict writeonly uniform image3D gridImage;
+layout(set=0, binding=2, rgba32f) restrict writeonly uniform image3D gridCopyImage;
#define SHARED_PARTICLES_BATCH_SIZE 64
@@ -38,9 +39,11 @@ void main() {
memoryBarrierShared();
for (uint i = 0; i < SHARED_PARTICLES_BATCH_SIZE; i++) {
+ vec3 weight = voxel_particle_weight(position, shared_particles[i]);
+
gridValue += (
vec4(shared_particles[i].velocity, shared_particles[i].mass) *
- voxel_particle_weight(position, shared_particles[i])
+ weight.x * weight.y * weight.z
);
}
}
@@ -51,5 +54,11 @@ void main() {
gridValue
);
+ imageStore(
+ gridCopyImage,
+ ivec3(gl_GlobalInvocationID),
+ gridValue
+ );
+
memoryBarrierImage();
}
\ No newline at end of file
diff --git a/projects/wobble_bobble/shaders/update_grid_forces.comp b/projects/wobble_bobble/shaders/update_grid_forces.comp
index 752c3eff..4ea302e7 100644
--- a/projects/wobble_bobble/shaders/update_grid_forces.comp
+++ b/projects/wobble_bobble/shaders/update_grid_forces.comp
@@ -7,8 +7,9 @@ layout(local_size_x = 4, local_size_y = 4, local_size_z = 4) in;
#include "particle.inc"
-layout(set=0, binding=0, rgba32f) uniform image3D gridImage;
-layout(set=0, binding=1, std430) buffer particleBuffer {
+layout(set=0, binding=0, rgba32f) restrict readonly uniform image3D gridImage;
+layout(set=0, binding=1, rgba32f) restrict writeonly uniform image3D gridForceImage;
+layout(set=0, binding=2, std430) buffer particleBuffer {
Particle particles [];
};
@@ -23,7 +24,7 @@ shared Particle shared_particles [SHARED_PARTICLES_BATCH_SIZE];
void main() {
const vec3 position = (vec3(gl_GlobalInvocationID) + vec3(0.5f)) / imageSize(gridImage);
- const float elasticity_module = 1200.5f * 1000000.0f; // 10..15 = Wood
+ const float elasticity_module = 2.5f * 1000000.0f; // 10..15 = Wood
memoryBarrierImage();
@@ -60,23 +61,30 @@ void main() {
float volume = 4.0f / 3.0f * PI * size * size * size;
mat3 deformation = mat3(shared_particles[gl_LocalInvocationIndex].deformation);
- mat3 epsilon = deformation - mat3(1.0f);
- mat3 delta = elasticity_module * epsilon;
- mat3 delta_cauchy = determinant(deformation) * delta * inverse(transpose(deformation));
+ float J = determinant(deformation);
- vec3 weight_gradient = vec3(
- voxel_particle_grad_weight(position, shared_particles[gl_LocalInvocationIndex].minimal)
- );
+ if ((abs(J) > 0.0f) && (volume > 0.0f)) {
+ mat3 epsilon = deformation - mat3(1.0f);
+ mat3 delta = elasticity_module * epsilon;
+ mat3 delta_cauchy = J * delta * inverse(transpose(deformation));
- force -= (
- volume *
- delta_cauchy *
- weight_gradient
- );
+ vec3 weight_gradient = voxel_particle_grad_weight(
+ position,
+ shared_particles[gl_LocalInvocationIndex].minimal
+ );
+
+ force -= (
+ volume *
+ delta_cauchy *
+ weight_gradient
+ );
+ }
}
}
- velocity += force * dt / mass;
+ if (mass > 0.0f) {
+ velocity += force * dt / mass;
+ }
bvec3 lowerID = lessThanEqual(gl_GlobalInvocationID, ivec3(0));
bvec3 negativeVelocity = lessThan(velocity, vec3(0.0f));
@@ -90,10 +98,10 @@ void main() {
(lowerID.z && negativeVelocity.z) || (greaterID.z && positiveVelocity.z)
);
- velocity = mix(velocity, -velocity, invert) - gridSample.xyz;
+ velocity = mix(velocity, -velocity, invert);
imageStore(
- gridImage,
+ gridForceImage,
ivec3(gl_GlobalInvocationID),
vec4(velocity, mass)
);
diff --git a/projects/wobble_bobble/shaders/update_particle_deformation.comp b/projects/wobble_bobble/shaders/update_particle_deformation.comp
index 7bfc923b..9711d48a 100644
--- a/projects/wobble_bobble/shaders/update_particle_deformation.comp
+++ b/projects/wobble_bobble/shaders/update_particle_deformation.comp
@@ -9,30 +9,46 @@ layout(set=0, binding=0, std430) buffer particleBuffer {
Particle particles [];
};
-layout(set=0, binding=1) uniform texture3D gridTextureIn;
+layout(set=0, binding=1) uniform texture3D gridImage;
layout(set=0, binding=2) uniform sampler gridSampler;
-layout( push_constant ) uniform constants {
- float t;
- float dt;
-};
-
void main() {
memoryBarrierBuffer();
memoryBarrierImage();
- ParticleMinimal particle = particles[gl_GlobalInvocationID.x].minimal;
- mat3 deformation = mat3(particles[gl_GlobalInvocationID.x].deformation);
+ if (gl_GlobalInvocationID.x < particles.length()) {
+ ParticleMinimal minimal = particles[gl_GlobalInvocationID.x].minimal;
+ mat3 deformation = mat3(particles[gl_GlobalInvocationID.x].deformation);
+
+ ivec3 gridResolution = textureSize(sampler3D(gridImage, gridSampler), 0);
+ ivec3 gridWindow = ivec3(minimal.size * 2.0f * gridResolution);
+
+ mat3 velocity_gradient = mat3(0.0f);
+
+ uint i, j, k;
+
+ for (i = -gridWindow.x; i <= gridWindow.x; i++) {
+ for (j = -gridWindow.y; j <= gridWindow.y; j++) {
+ for (k = -gridWindow.z; k <= gridWindow.z; k++) {
+ vec3 offset = vec3(i, j, k) / gridResolution;
+ vec3 voxel = minimal.position + offset;
+
+ if (length(offset) < minimal.size * 2.0f) {
+ vec4 gridSample = texture(sampler3D(gridImage, gridSampler), voxel);
- mat3 grad_velocity = mat3(
- textureGrad(sampler3D(gridTextureIn, gridSampler), particle.position, vec3(1.0f, 0.0f, 0.0f), vec3(0.0f)).xyz,
- textureGrad(sampler3D(gridTextureIn, gridSampler), particle.position, vec3(0.0f, 1.0f, 0.0f), vec3(0.0f)).xyz,
- textureGrad(sampler3D(gridTextureIn, gridSampler), particle.position, vec3(0.0f, 0.0f, 1.0f), vec3(0.0f)).xyz
- );
+ velocity_gradient += outerProduct(
+ gridSample.xyz,
+ voxel_particle_grad_weight(voxel, minimal)
+ );
+ }
+ }
+ }
+ }
- mat3 deformation_elastic = (mat3(1.0f) + grad_velocity * dt) * deformation;
+ mat3 deformation_elastic = (mat3(1.0f) + velocity_gradient) * deformation;
- particles[gl_GlobalInvocationID.x].deformation = mat4(deformation_elastic);
+ particles[gl_GlobalInvocationID.x].deformation = mat4(deformation_elastic);
+ }
memoryBarrierBuffer();
}
\ No newline at end of file
diff --git a/projects/wobble_bobble/shaders/update_particle_velocities.comp b/projects/wobble_bobble/shaders/update_particle_velocities.comp
index 2c4f9e4f..123ac83a 100644
--- a/projects/wobble_bobble/shaders/update_particle_velocities.comp
+++ b/projects/wobble_bobble/shaders/update_particle_velocities.comp
@@ -10,7 +10,8 @@ layout(set=0, binding=0, std430) buffer particleBuffer {
};
layout(set=0, binding=1) uniform texture3D gridImage;
-layout(set=0, binding=2) uniform sampler gridSampler;
+layout(set=0, binding=2) uniform texture3D gridOldImage;
+layout(set=0, binding=3) uniform sampler gridSampler;
void main() {
memoryBarrierBuffer();
@@ -20,7 +21,7 @@ void main() {
ParticleMinimal minimal = particles[gl_GlobalInvocationID.x].minimal;
ivec3 gridResolution = textureSize(sampler3D(gridImage, gridSampler), 0);
- ivec3 gridWindow = ivec3(minimal.size * 4.0f * gridResolution);
+ ivec3 gridWindow = ivec3(minimal.size * 2.0f * gridResolution);
vec3 velocity = vec3(minimal.velocity);
@@ -34,7 +35,11 @@ void main() {
if (length(offset) < minimal.size * 2.0f) {
vec4 gridSample = texture(sampler3D(gridImage, gridSampler), voxel);
- velocity += voxel_particle_weight(voxel, minimal) * gridSample.xyz;
+ vec4 gridOldSample = texture(sampler3D(gridOldImage, gridSampler), voxel);
+
+ vec3 weight = voxel_particle_weight(voxel, minimal);
+
+ velocity += (weight.x * weight.y * weight.z) * (gridSample.xyz - gridOldSample.xyz);
}
}
}
diff --git a/projects/wobble_bobble/src/main.cpp b/projects/wobble_bobble/src/main.cpp
index b7ab85c6..f386cc15 100644
--- a/projects/wobble_bobble/src/main.cpp
+++ b/projects/wobble_bobble/src/main.cpp
@@ -40,7 +40,7 @@ void distributeParticles(Particle *particles, size_t count, const glm::vec3& cen
particles[i].position = center + offset;
particles[i].size = size;
- particles[i].velocity = glm::vec3(0.0f, 1.0f, 0.0f);
+ particles[i].velocity = glm::vec3(0.0f, 0.1f, 0.0f);
volume += size;
}
@@ -153,6 +153,17 @@ int main(int argc, const char **argv) {
grid.switchLayout(vk::ImageLayout::eGeneral);
+ vkcv::Image gridCopy = core.createImage(
+ grid.getFormat(),
+ grid.getWidth(),
+ grid.getHeight(),
+ grid.getDepth(),
+ false,
+ true
+ );
+
+ gridCopy.switchLayout(vk::ImageLayout::eGeneral);
+
/* TODO: clear grid via compute shader?
std::vector<glm::vec4> grid_vec (grid.getWidth() * grid.getHeight() * grid.getDepth());
@@ -185,6 +196,7 @@ int main(int argc, const char **argv) {
vkcv::DescriptorWrites writes;
writes.storageBufferWrites.push_back(vkcv::BufferDescriptorWrite(0, particles.getHandle()));
writes.storageImageWrites.push_back(vkcv::StorageImageDescriptorWrite(1, grid.getHandle()));
+ writes.storageImageWrites.push_back(vkcv::StorageImageDescriptorWrite(2, gridCopy.getHandle()));
core.writeDescriptorSet(transformParticlesToGridSets[0], writes);
}
@@ -210,8 +222,9 @@ int main(int argc, const char **argv) {
{
vkcv::DescriptorWrites writes;
- writes.storageImageWrites.push_back(vkcv::StorageImageDescriptorWrite(0, grid.getHandle()));
- writes.storageBufferWrites.push_back(vkcv::BufferDescriptorWrite(1, particles.getHandle()));
+ writes.storageImageWrites.push_back(vkcv::StorageImageDescriptorWrite(0, gridCopy.getHandle()));
+ writes.storageImageWrites.push_back(vkcv::StorageImageDescriptorWrite(1, grid.getHandle()));
+ writes.storageBufferWrites.push_back(vkcv::BufferDescriptorWrite(2, particles.getHandle()));
core.writeDescriptorSet(updateGridForcesSets[0], writes);
}
@@ -241,7 +254,8 @@ int main(int argc, const char **argv) {
vkcv::DescriptorWrites writes;
writes.storageBufferWrites.push_back(vkcv::BufferDescriptorWrite(0, particles.getHandle()));
writes.sampledImageWrites.push_back(vkcv::SampledImageDescriptorWrite(1, grid.getHandle()));
- writes.samplerWrites.push_back(vkcv::SamplerDescriptorWrite(2, gridSampler));
+ writes.sampledImageWrites.push_back(vkcv::SampledImageDescriptorWrite(2, gridCopy.getHandle()));
+ writes.samplerWrites.push_back(vkcv::SamplerDescriptorWrite(3, gridSampler));
core.writeDescriptorSet(updateParticleVelocitiesSets[0], writes);
}
@@ -467,6 +481,7 @@ int main(int argc, const char **argv) {
core.recordBeginDebugLabel(cmdStream, "TRANSFORM PARTICLES TO GRID", { 0.47f, 0.77f, 0.85f, 1.0f });
core.prepareImageForStorage(cmdStream, grid.getHandle());
+ core.prepareImageForStorage(cmdStream, gridCopy.getHandle());
core.recordComputeDispatchToCmdStream(
cmdStream,
@@ -479,6 +494,7 @@ int main(int argc, const char **argv) {
);
core.recordImageMemoryBarrier(cmdStream, grid.getHandle());
+ core.recordImageMemoryBarrier(cmdStream, gridCopy.getHandle());
core.recordEndDebugLabel(cmdStream);
if (!initializedParticleVolumes) {
@@ -508,6 +524,8 @@ int main(int argc, const char **argv) {
) },
timePushConstants
);
+
+ core.recordImageMemoryBarrier(cmdStream, grid.getHandle());
core.recordEndDebugLabel(cmdStream);
core.recordBeginDebugLabel(cmdStream, "UPDATE PARTICLE DEFORMATION", { 0.78f, 0.89f, 0.94f, 1.0f });
@@ -520,13 +538,15 @@ int main(int argc, const char **argv) {
{ vkcv::DescriptorSetUsage(
0, core.getDescriptorSet(updateParticleDeformationSets[0]).vulkanHandle
) },
- timePushConstants
+ vkcv::PushConstants(0)
);
core.recordBufferMemoryBarrier(cmdStream, particles.getHandle());
core.recordEndDebugLabel(cmdStream);
core.recordBeginDebugLabel(cmdStream, "UPDATE PARTICLE VELOCITIES", { 0.78f, 0.89f, 0.94f, 1.0f });
+ core.prepareImageForSampling(cmdStream, gridCopy.getHandle());
+
core.recordComputeDispatchToCmdStream(
cmdStream,
updateParticleVelocitiesPipeline,
--
GitLab