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Fixed bloom in path tracing #172

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Merged
maxvdec merged 1 commit into from
Jul 19, 2026
Merged

Fixed bloom in path tracing #172

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86 changes: 53 additions & 33 deletions atlas/application/window.cpp
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Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -932,7 +932,8 @@ Window::Window(const WindowConfiguration &config)
#ifdef METAL
this->externalMetalView = config.metalTargetView;
this->renderToExternalMetalView = this->externalMetalView != nullptr;
this->showHostWindow = config.showHostWindow && !this->renderToExternalMetalView;
this->showHostWindow =
config.showHostWindow && !this->renderToExternalMetalView;
#else
(void)config.metalTargetView;
this->externalMetalView = nullptr;
Expand Down Expand Up @@ -1638,6 +1639,15 @@ bool Window::stepFrame() {
pathTracer->copySrcFramebuffer, pathTracer->copyDstFramebuffer,
0);
commandBuffer->performResolve(copy);

pathTracer->copySrcFramebuffer->attachTexture(
pathTracer->pathTracingTextureBright->texture, 0);
pathTracer->copyDstFramebuffer->attachTexture(
target->brightTexture.texture, 0);
auto brightCopy = opal::ResolveAction::createForColorAttachment(
pathTracer->copySrcFramebuffer, pathTracer->copyDstFramebuffer,
0);
commandBuffer->performResolve(brightCopy);
#endif

continue;
Expand Down Expand Up @@ -1710,7 +1720,8 @@ bool Window::stepFrame() {
if (obj->canUseDeferredRendering()) {
return;
}
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) return;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
return;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
Expand All @@ -1729,7 +1740,8 @@ bool Window::stepFrame() {
}

for (auto &obj : this->lateForwardRenderables) {
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
Expand All @@ -1748,7 +1760,8 @@ bool Window::stepFrame() {
renderEditorGrid(commandBuffer);

for (auto &obj : this->firstRenderables) {
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
Expand All @@ -1759,15 +1772,17 @@ bool Window::stepFrame() {
if (obj->renderLateForward) {
continue;
}
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
shouldRefreshPipeline(obj));
}
updateFluidCaptures(commandBuffer);
for (auto &obj : this->lateForwardRenderables) {
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
Expand Down Expand Up @@ -1812,7 +1827,8 @@ bool Window::stepFrame() {
this->currentRenderTarget = this->screenRenderTarget.get();
renderEditorGrid(commandBuffer);
for (auto &obj : this->firstRenderables) {
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
Expand All @@ -1823,7 +1839,8 @@ bool Window::stepFrame() {
if (obj->renderLateForward) {
continue;
}
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
Expand All @@ -1833,7 +1850,8 @@ bool Window::stepFrame() {
updateFluidCaptures(commandBuffer);

for (auto &obj : this->lateForwardRenderables) {
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer,
Expand All @@ -1846,7 +1864,8 @@ bool Window::stepFrame() {
}

for (auto &obj : this->preferenceRenderables) {
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(this->camera->calculateViewMatrix());
obj->setProjectionMatrix(calculateProjectionMatrix());
obj->render(getDeltaTime(), commandBuffer, shouldRefreshPipeline(obj));
Expand Down Expand Up @@ -2068,11 +2087,10 @@ void Window::setEditorKeyboardTransformAxes(int axes) {
if (!editorKeyboardTransform)
return;
editorKeyboardTransformAxes = std::clamp(axes, 1, 7);
editorActiveGizmoAxis =
editorKeyboardTransformAxes == 1 ? 1
: editorKeyboardTransformAxes == 2 ? 2
: editorKeyboardTransformAxes == 4 ? 3
: 0;
editorActiveGizmoAxis = editorKeyboardTransformAxes == 1 ? 1
: editorKeyboardTransformAxes == 2 ? 2
: editorKeyboardTransformAxes == 4 ? 3
: 0;
}

void Window::finishEditorKeyboardTransform(bool commit) {
Expand Down Expand Up @@ -2694,12 +2712,15 @@ void Window::updateEditorDrag(float x, float y, float scale) {
std::max(0.05f, editorDragStartObjectScale.z + scaleDelta);
}
if (editorTransformSnapping) {
nextScale.x = std::round(nextScale.x / editorTransformSnapIncrement) *
editorTransformSnapIncrement;
nextScale.y = std::round(nextScale.y / editorTransformSnapIncrement) *
editorTransformSnapIncrement;
nextScale.z = std::round(nextScale.z / editorTransformSnapIncrement) *
editorTransformSnapIncrement;
nextScale.x =
std::round(nextScale.x / editorTransformSnapIncrement) *
editorTransformSnapIncrement;
nextScale.y =
std::round(nextScale.y / editorTransformSnapIncrement) *
editorTransformSnapIncrement;
nextScale.z =
std::round(nextScale.z / editorTransformSnapIncrement) *
editorTransformSnapIncrement;
nextScale.x = std::max(0.001f, nextScale.x);
nextScale.y = std::max(0.001f, nextScale.y);
nextScale.z = std::max(0.001f, nextScale.z);
Expand Down Expand Up @@ -2735,8 +2756,8 @@ void Window::updateEditorKeyboardTransform(float x, float y, float scale) {
const float dx = editorKeyboardAccumulatedX / effectiveScale;
const float dy = editorKeyboardAccumulatedY / effectiveScale;
const int axes = editorKeyboardTransformAxes;
const float distance = glm::length(editorDragStartPosition.toGlm() -
camera->position.toGlm());
const float distance =
glm::length(editorDragStartPosition.toGlm() - camera->position.toGlm());

if (editorControlMode == EditorControlMode::Move) {
glm::vec3 delta(0.0f);
Expand All @@ -2752,10 +2773,8 @@ void Window::updateEditorKeyboardTransform(float x, float y, float scale) {
const float sensitivity = std::max(0.0025f, distance * 0.0025f);
delta = (right * dx + up * dy) * sensitivity;
} else {
const float viewWidth =
std::max(1.0f, static_cast<float>(width));
const float viewHeight =
std::max(1.0f, static_cast<float>(height));
const float viewWidth = std::max(1.0f, static_cast<float>(width));
const float viewHeight = std::max(1.0f, static_cast<float>(height));
const glm::mat4 viewProjection =
calculateProjectionMatrix() * camera->calculateViewMatrix();
const glm::vec3 center = editorDragStartPosition.toGlm();
Expand Down Expand Up @@ -3992,10 +4011,9 @@ void Window::addRenderTarget(RenderTarget *target) {
}

void Window::removeRenderTarget(RenderTarget *target) {
this->renderTargets.erase(
std::remove(this->renderTargets.begin(), this->renderTargets.end(),
target),
this->renderTargets.end());
this->renderTargets.erase(std::remove(this->renderTargets.begin(),
this->renderTargets.end(), target),
this->renderTargets.end());
if (this->currentRenderTarget == target) {
this->currentRenderTarget = nullptr;
}
Expand Down Expand Up @@ -4870,7 +4888,8 @@ void Window::captureFluidReflection(
if (dynamic_cast<Fluid *>(obj) == &fluid) {
continue;
}
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(view);
obj->setProjectionMatrix(projection);
obj->render(getDeltaTime(), commandBuffer,
Expand Down Expand Up @@ -4997,7 +5016,8 @@ void Window::captureFluidRefraction(
if (dynamic_cast<Fluid *>(obj) == &fluid) {
continue;
}
if (obj && obj->editorOnly && !this->areEditorControlsEnabled()) continue;
if (obj && obj->editorOnly && !this->areEditorControlsEnabled())
continue;
obj->setViewMatrix(view);
obj->setProjectionMatrix(projection);
obj->render(getDeltaTime(), commandBuffer,
Expand Down
23 changes: 22 additions & 1 deletion include/atlas/core/default_shaders.h
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Original file line number Diff line number Diff line change
Expand Up @@ -7561,6 +7561,7 @@ R"( float3(vertices[bj2].tangent) * bb2,

kernel void main0(texture2d<float, access::write> outTex [[texture(0)]],
texture2d<float, access::read> prevTex [[texture(1)]],
texture2d<float, access::write> brightTex [[texture(2)]],
instance_acceleration_structure sceneAS [[buffer(0)]],
constant CameraUniforms &cam [[buffer(1)]],
constant Material *materials [[buffer(2)]],
Expand Down Expand Up @@ -7632,7 +7633,27 @@ kernel void main0(texture2d<float, access::write> outTex [[texture(0)]],

float3 accum = (prevColor.xyz * frameIndex + color) / (frameIndex + 1);
accum = clampLuminance(accum, 24.0);
outTex.write(float4(accum, 1.0), gid);

constexpr float bloomThreshold = 1.0;
constexpr float bloomKnee = 0.5;

float brightness = luminance(accum);
float soft = clamp(
brightness - bloomThreshold + bloomKnee,
0.0,
bloomKnee * 2.0
);

soft = soft * soft / max(bloomKnee * 4.0, 0.00001);

float contribution =
max(brightness - bloomThreshold, soft) /
max(brightness, 0.00001);

float3 brightColor = accum * contribution;

outTex.write(float4(accum, 1.0), gid);
brightTex.write(float4(brightColor, 1.0), gid);
}
)",
};
Expand Down
1 change: 1 addition & 0 deletions include/photon/illuminate.h
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Original file line number Diff line number Diff line change
Expand Up @@ -90,6 +90,7 @@ class PathTracing {
std::shared_ptr<Texture> pathTracingTexture;
/** @brief Previous frame output texture used for accumulation. */
std::shared_ptr<Texture> pathTracingTexturePrev;
std::shared_ptr<Texture> pathTracingTextureBright;

/** @brief Rays traced per pixel each dispatch. */
int raysPerPixel = 4;
Expand Down
4 changes: 4 additions & 0 deletions justfile
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Original file line number Diff line number Diff line change
Expand Up @@ -120,3 +120,7 @@ release backend="AUTO":
run-docs:
just docs
python3 -m http.server 8000 --directory docs/html

editor backend="AUTO" bezel_native="OFF":
just target AtlasEditor {{ backend }} {{ bezel_native }}
"./build/bin/Atlas Engine.app/Contents/MacOS/Atlas Engine"
11 changes: 10 additions & 1 deletion photon/path_tracing.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -178,6 +178,9 @@ void photon::PathTracing::init() {
pathTracingTexturePrev = std::make_shared<Texture>(
Texture::create(outputWidth, outputHeight, opal::TextureFormat::Rgba16F,
opal::TextureDataFormat::Rgba, TextureType::Color));
pathTracingTextureBright = std::make_shared<Texture>(
Texture::create(outputWidth, outputHeight, opal::TextureFormat::Rgba16F,
opal::TextureDataFormat::Rgba, TextureType::Color));

copySrcFramebuffer = std::make_shared<opal::Framebuffer>();
copyDstFramebuffer = std::make_shared<opal::Framebuffer>();
Expand All @@ -187,7 +190,8 @@ void photon::PathTracing::resizeOutput(int width, int height) {
const int newWidth = std::max(1, width);
const int newHeight = std::max(1, height);
if (newWidth == outputWidth && newHeight == outputHeight &&
pathTracingTexture != nullptr && pathTracingTexturePrev != nullptr) {
pathTracingTexture != nullptr && pathTracingTexturePrev != nullptr &&
pathTracingTextureBright != nullptr) {
return;
}

Expand All @@ -199,6 +203,9 @@ void photon::PathTracing::resizeOutput(int width, int height) {
pathTracingTexturePrev = std::make_shared<Texture>(
Texture::create(outputWidth, outputHeight, opal::TextureFormat::Rgba16F,
opal::TextureDataFormat::Rgba, TextureType::Color));
pathTracingTextureBright = std::make_shared<Texture>(
Texture::create(outputWidth, outputHeight, opal::TextureFormat::Rgba16F,
opal::TextureDataFormat::Rgba, TextureType::Color));
frameIndex = 0;
}

Expand Down Expand Up @@ -743,6 +750,8 @@ void photon::PathTracing::render(
pathTracingPipeline->bindTexture("outTex", pathTracingTexture->texture, 0);
pathTracingPipeline->bindTexture("prevTex", pathTracingTexturePrev->texture,
1);
pathTracingPipeline->bindTexture("brightTex",
pathTracingTextureBright->texture, 2);

static std::shared_ptr<opal::Texture> fallbackSkyboxTexture = nullptr;
if (fallbackSkyboxTexture == nullptr) {
Expand Down
23 changes: 22 additions & 1 deletion shaders/metal/path_tracing/path.metal
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Original file line number Diff line number Diff line change
Expand Up @@ -1184,6 +1184,7 @@ float3 sampleRadiance(uint2 gid, uint sampleIndex, uint w,

kernel void main0(texture2d<float, access::write> outTex [[texture(0)]],
texture2d<float, access::read> prevTex [[texture(1)]],
texture2d<float, access::write> brightTex [[texture(2)]],
instance_acceleration_structure sceneAS [[buffer(0)]],
constant CameraUniforms &cam [[buffer(1)]],
constant Material *materials [[buffer(2)]],
Expand Down Expand Up @@ -1255,5 +1256,25 @@ kernel void main0(texture2d<float, access::write> outTex [[texture(0)]],

float3 accum = (prevColor.xyz * frameIndex + color) / (frameIndex + 1);
accum = clampLuminance(accum, 24.0);
outTex.write(float4(accum, 1.0), gid);

constexpr float bloomThreshold = 1.0;
constexpr float bloomKnee = 0.5;

float brightness = luminance(accum);
float soft = clamp(
brightness - bloomThreshold + bloomKnee,
0.0,
bloomKnee * 2.0
);

soft = soft * soft / max(bloomKnee * 4.0, 0.00001);

float contribution =
max(brightness - bloomThreshold, soft) /
max(brightness, 0.00001);

float3 brightColor = accum * contribution;

outTex.write(float4(accum, 1.0), gid);
brightTex.write(float4(brightColor, 1.0), gid);
}
1 change: 1 addition & 0 deletions tests/path-tracing/main.ascene
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Original file line number Diff line number Diff line change
Expand Up @@ -132,6 +132,7 @@
"targets": [
{
"display": true,
"effects": [],
"name": "Main Target",
"render": true,
"type": "scene"
Expand Down
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