GoaLitiuM/FlaxEngine
1
0
Fork 0
Code Issues Pull Requests Actions 7 Packages Projects Releases Wiki Activity

Refactor DDGI fallback radiance to use alpha for blending between fixed color and color at snapped location of the last cascade

Browse Source 
This means artists don't need to adjust the value anymore as it can cover vista geometry with GI at last cascade borders.
This commit is contained in:
Wojtek Figat
2026-01-05 16:22:00 +01:00
parent c5a28a5734
commit 11ea889fa9
6 changed files with 38 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files

2
Source/Engine/Graphics/Materials/MaterialShaderFeatures.cpp
View File

@@ -191,7 +191,7 @@ bool GlobalIlluminationFeature::Bind(MaterialShader::BindParameters& params, Spa
{
// Unbind SRVs to prevent issues
data.DDGI.CascadesCount = 0;
data.DDGI.FallbackIrradiance = Float3::Zero;
data.DDGI.FallbackIrradiance = Float4::Zero;
params.GPUContext->UnBindSR(srv + 0);
params.GPUContext->UnBindSR(srv + 1);
params.GPUContext->UnBindSR(srv + 2);

2
Source/Engine/Graphics/PostProcessSettings.h
View File

@@ -378,7 +378,7 @@ API_STRUCT() struct FLAXENGINE_API GlobalIlluminationSettings : ISerializable
/// The irradiance lighting outside the GI range used as a fallback to prevent pure-black scene outside the Global Illumination range.
/// </summary>
API_FIELD(Attributes="EditorOrder(40), PostProcessSetting((int)GlobalIlluminationSettingsOverride.FallbackIrradiance)")
Color FallbackIrradiance = Color::Black;
Color FallbackIrradiance = Color::Transparent;
public:
/// <summary>

3
Source/Engine/Renderer/GI/DynamicDiffuseGlobalIllumination.cpp
View File

@@ -328,7 +328,6 @@ bool DynamicDiffuseGlobalIlluminationPass::RenderInner(RenderContext& renderCont
const float indirectLightingIntensity = settings.Intensity;
const float probeHistoryWeight = Math::Clamp(settings.TemporalResponse, 0.0f, 0.98f);
const float distance = settings.Distance;
const Color fallbackIrradiance = settings.FallbackIrradiance;
// Automatically calculate amount of cascades to cover the GI distance at the current probes spacing
const int32 idealProbesCount = 20; // Ideal amount of probes per-cascade to try to fit in order to cover whole distance
@@ -518,7 +517,7 @@ bool DynamicDiffuseGlobalIlluminationPass::RenderInner(RenderContext& renderCont
ddgiData.Result.Constants.ProbeHistoryWeight = probeHistoryWeight;
ddgiData.Result.Constants.IrradianceGamma = 1.5f;
ddgiData.Result.Constants.IndirectLightingIntensity = indirectLightingIntensity;
ddgiData.Result.Constants.FallbackIrradiance = fallbackIrradiance.ToFloat3() * fallbackIrradiance.A;
ddgiData.Result.Constants.FallbackIrradiance = settings.FallbackIrradiance.ToFloat4();
ddgiData.Result.ProbesData = ddgiData.ProbesData->View();
ddgiData.Result.ProbesDistance = ddgiData.ProbesDistance->View();
ddgiData.Result.ProbesIrradiance = ddgiData.ProbesIrradiance->View();

3
Source/Engine/Renderer/GI/DynamicDiffuseGlobalIllumination.h
View File

@@ -25,8 +25,7 @@ public:
float IndirectLightingIntensity;
Float3 ViewPos;
uint32 RaysCount;
Float3 FallbackIrradiance;
float Padding0;
Float4 FallbackIrradiance;
});
// Binding data for the GPU.

33
Source/Shaders/GI/DDGI.hlsl
View File

@@ -44,8 +44,7 @@ struct DDGIData
float IndirectLightingIntensity;
float3 ViewPos;
uint RaysCount;
float3 FallbackIrradiance;
float Padding0;
float4 FallbackIrradiance;
};
uint GetDDGIProbeIndex(DDGIData data, uint3 probeCoords)
@@ -164,6 +163,8 @@ float2 GetDDGIProbeUV(DDGIData data, uint cascadeIndex, uint probeIndex, float2
float3 SampleDDGIIrradianceCascade(DDGIData data, Texture2D<snorm float4> probesData, Texture2D<float4> probesDistance, Texture2D<float4> probesIrradiance, float3 worldPosition, float3 worldNormal, uint cascadeIndex, float3 probesOrigin, float3 probesExtent, float probesSpacing, float3 biasedWorldPosition)
{
bool invalidCascade = cascadeIndex >= data.CascadesCount;
cascadeIndex = min(cascadeIndex, data.CascadesCount - 1);
uint3 probeCoordsEnd = data.ProbesCounts - uint3(1, 1, 1);
uint3 baseProbeCoords = clamp(uint3((worldPosition - probesOrigin + probesExtent) / probesSpacing), uint3(0, 0, 0), probeCoordsEnd);
@@ -190,11 +191,11 @@ float3 SampleDDGIIrradianceCascade(DDGIData data, Texture2D<snorm float4> probes
uint3 fallbackCoords = DDGI_FALLBACK_COORDS_DECODE(probeData);
float fallbackToProbeDist = length((float3)probeCoords - (float3)fallbackCoords);
useVisibility = fallbackToProbeDist <= 1.0f; // Skip visibility test that blocks too far probes due to limiting max distance to 1.5 of probe spacing
if (fallbackToProbeDist > 2.0f)
minWight = 1.0f;
if (fallbackToProbeDist > 2.0f) minWight = 1.0f;
probeCoords = fallbackCoords;
probeIndex = GetDDGIScrollingProbeIndex(data, cascadeIndex, fallbackCoords);
probeData = LoadDDGIProbeData(data, probesData, cascadeIndex, probeIndex);
//if (DecodeDDGIProbeState(probeData) == DDGI_PROBE_STATE_INACTIVE) continue;
}
// Calculate probe position
@@ -264,7 +265,8 @@ float3 SampleDDGIIrradianceCascade(DDGIData data, Texture2D<snorm float4> probes
{
// Normalize irradiance
//irradiance.rgb /= irradiance.a;
irradiance.rgb /= lerp(1, irradiance.a, saturate(irradiance.a * irradiance.a + 0.9f));
//irradiance.rgb /= lerp(1, irradiance.a, saturate(irradiance.a * irradiance.a + 0.9f));
irradiance.rgb /= invalidCascade ? irradiance.a : lerp(1, irradiance.a, saturate(irradiance.a * irradiance.a + 0.9f));
#if DDGI_SRGB_BLENDING
irradiance.rgb *= irradiance.rgb;
#endif
@@ -319,16 +321,13 @@ float3 SampleDDGIIrradiance(DDGIData data, Texture2D<snorm float4> probesData, T
break;
}
#endif
if (cascadeIndex == data.CascadesCount)
return data.FallbackIrradiance;
// Sample cascade
float3 result = SampleDDGIIrradianceCascade(data, probesData, probesDistance, probesIrradiance, worldPosition, worldNormal, cascadeIndex, probesOrigin, probesExtent, probesSpacing, biasedWorldPosition);
// Blend with the next cascade (or fallback irradiance outside the volume)
cascadeIndex++;
#if DDGI_CASCADE_BLEND_SMOOTH && !defined(DDGI_DEBUG_CASCADE)
result *= cascadeWeight;
cascadeIndex++;
if (cascadeIndex < data.CascadesCount && cascadeWeight < 0.99f)
{
probesSpacing = data.ProbesOriginAndSpacing[cascadeIndex].w;
@@ -336,18 +335,16 @@ float3 SampleDDGIIrradiance(DDGIData data, Texture2D<snorm float4> probesData, T
probesExtent = (data.ProbesCounts - 1) * (probesSpacing * 0.5f);
biasedWorldPosition = worldPosition + GetDDGISurfaceBias(viewDir, probesSpacing, worldNormal, bias);
float3 resultNext = SampleDDGIIrradianceCascade(data, probesData, probesDistance, probesIrradiance, worldPosition, worldNormal, cascadeIndex, probesOrigin, probesExtent, probesSpacing, biasedWorldPosition);
result *= cascadeWeight;
result += resultNext * (1 - cascadeWeight);
}
else
{
result += data.FallbackIrradiance * (1 - cascadeWeight);
}
#else
if (cascadeIndex == data.CascadesCount)
{
result += data.FallbackIrradiance * (1 - cascadeWeight);
}
#endif
if (cascadeIndex >= data.CascadesCount)
{
// Blend between the last cascade and the fallback irradiance
float fallbackWeight = (1 - cascadeWeight) * data.FallbackIrradiance.a;
result = lerp(result, data.FallbackIrradiance.rgb, fallbackWeight);
}
return result;
}

22
Source/Shaders/GI/DDGI.shader
View File

@@ -102,6 +102,11 @@ float3 Remap(float3 value, float3 fromMin, float3 fromMax, float3 toMin, float3
return (value - fromMin) / (fromMax - fromMin) * (toMax - toMin) + toMin;
}
bool IsProbeAtBorder(uint3 probeCoords)
{
return min(probeCoords.x, min(probeCoords.y, probeCoords.z)) == 0 || probeCoords.x == DDGI.ProbesCounts.x - 1 || probeCoords.y == DDGI.ProbesCounts.y - 1 || probeCoords.z == DDGI.ProbesCounts.z - 1;
}
// Compute shader for updating probes state between active and inactive and performing probes relocation.
META_CS(true, FEATURE_LEVEL_SM5)
[numthreads(DDGI_PROBE_CLASSIFY_GROUP_SIZE, 1, 1)]
@@ -183,16 +188,27 @@ void CS_Classify(uint3 DispatchThreadId : SV_DispatchThreadID)
float voxelLimit = GlobalSDF.CascadeVoxelSize[CascadeIndex] * 0.8f;
float distanceLimit = probesSpacing * ProbesDistanceLimits[CascadeIndex];
float relocateLimit = probesSpacing * ProbesRelocateLimits[CascadeIndex];
#ifdef DDGI_PROBE_EMPTY_AREA_DENSITY
uint3 probeCoordsStable = GetDDGIProbeCoords(DDGI, probeIndex);
if (sdf > probesSpacing * DDGI.ProbesCounts.x * 0.3f &&
probeCoordsStable.x % DDGI_PROBE_EMPTY_AREA_DENSITY == 0 && probeCoordsStable.y % DDGI_PROBE_EMPTY_AREA_DENSITY == 0 && probeCoordsStable.z % DDGI_PROBE_EMPTY_AREA_DENSITY == 0)
if (sdf > probesSpacing * DDGI.ProbesCounts.x * 0.3f
#if DDGI_PROBE_EMPTY_AREA_DENSITY > 1
&& (
// Low-density grid grid
(probeCoordsStable.x % DDGI_PROBE_EMPTY_AREA_DENSITY == 0 && probeCoordsStable.y % DDGI_PROBE_EMPTY_AREA_DENSITY == 0 && probeCoordsStable.z % DDGI_PROBE_EMPTY_AREA_DENSITY == 0)
// Edge probes at the last cascade (for good fallback irradiance outside the GI distance)
//|| (CascadeIndex + 1 == DDGI.CascadesCount && IsProbeAtBorder(probeCoords))
)
#endif
)
{
// Addd some fallback probes in empty areas to provide valid GI for nearby dynamic objects or transparency
probeOffset = float3(0, 0, 0);
probeState = wasScrolled || probeStateOld == DDGI_PROBE_STATE_INACTIVE ? DDGI_PROBE_STATE_ACTIVATED : DDGI_PROBE_STATE_ACTIVE;
probeAttention = DDGI_PROBE_ATTENTION_MIN;
}
else if (sdfDst > distanceLimit + length(probeOffset))
else
#endif
if (sdfDst > distanceLimit + length(probeOffset))
{
// Probe is too far from geometry (or deep inside) so disable it
probeOffset = float3(0, 0, 0);