Skip to content

Simple SubstrateMaterials support #119

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
kevor wants to merge 5 commits into
base: master
Choose a base branch
from
Open

Simple SubstrateMaterials support #119

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
c72a8ab
Added support for KHR_materials_iridescence params
kevor Mar 1, 2026
4f5b822
Fixed default iridescence param value
kevor Mar 1, 2026
e0cb1d0
Added Simple SubstrateMaterials support
kevor Mar 2, 2026
ea2c63e
Added Simple support for AlphaComposite
kevor Mar 3, 2026
8658823
Added support for simplified Single Slab Transmittance
kevor Mar 3, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
71 changes: 67 additions & 4 deletions Source/glTFRuntime/Private/glTFRuntimeParserMaterials.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -329,6 +329,37 @@ UMaterialInterface* FglTFRuntimeParser::LoadMaterial_Internal(const int32 Index,
GetMaterialTexture(JsonMaterialSheen->ToSharedRef(), "sheenRoughnessTexture", false, RuntimeMaterial.SheenRoughnessTextureCache, RuntimeMaterial.SheenRoughnessTextureMips, RuntimeMaterial.SheenRoughnessTextureTransform, RuntimeMaterial.SheenRoughnessTextureSampler, false);
RuntimeMaterial.bKHR_materials_sheen = true;
}

// KHR_materials_iridescence
const TSharedPtr<FJsonObject>* JsonMaterialIridescence;
if ((*JsonExtensions)->TryGetObjectField(TEXT("KHR_materials_iridescence"), JsonMaterialIridescence))
{
if (!(*JsonMaterialIridescence)->TryGetNumberField(TEXT("iridescenceFactor"), RuntimeMaterial.IridescenceFactor))
{
RuntimeMaterial.IridescenceFactor = 0;
}

if (!(*JsonMaterialIridescence)->TryGetNumberField(TEXT("iridescenceIor"), RuntimeMaterial.IridescenceIor))
{
RuntimeMaterial.IridescenceIor = 1.3;
}

if (!(*JsonMaterialIridescence)->TryGetNumberField(TEXT("iridescenceThicknessMinimum"), RuntimeMaterial.IridescenceThicknessMinimum))
{
RuntimeMaterial.IridescenceThicknessMinimum = 100;
}

if (!(*JsonMaterialIridescence)->TryGetNumberField(TEXT("iridescenceThicknessMaximum"), RuntimeMaterial.IridescenceThicknessMaximum))
{
RuntimeMaterial.IridescenceThicknessMaximum = 400;
}

GetMaterialTexture(JsonMaterialIridescence->ToSharedRef(), "iridescenceTexture", false, RuntimeMaterial.IridescenceTextureCache, RuntimeMaterial.IridescenceTextureMips, RuntimeMaterial.IridescenceTextureTransform, RuntimeMaterial.IridescenceTextureSampler, false);
GetMaterialTexture(JsonMaterialIridescence->ToSharedRef(), "iridescenceThicknessTexture", false, RuntimeMaterial.IridescenceThicknessTextureCache, RuntimeMaterial.IridescenceThicknessTextureMips, RuntimeMaterial.IridescenceThicknessTextureTransform, RuntimeMaterial.IridescenceThicknessTextureSampler, false);

RuntimeMaterial.bKHR_materials_iridescence = true;
}

}

if (IsInGameThread())
Expand Down Expand Up @@ -649,18 +680,33 @@ UMaterialInterface* FglTFRuntimeParser::BuildMaterial(const int32 Index, const F
{
if (MaterialsConfig.bUseSubstrateMaterials && !RuntimeMaterial.bKHR_materials_unlit && !RuntimeMaterial.bKHR_materials_pbrSpecularGlossiness)
{
EglTFRuntimeSubstrateMaterialType SubstrateMaterialType = RuntimeMaterial.bTwoSided ? EglTFRuntimeSubstrateMaterialType::OpaqueTwoSided : EglTFRuntimeSubstrateMaterialType::Opaque;
bool bIsSimpleSlab = true;
if (RuntimeMaterial.bKHR_materials_clearcoat || RuntimeMaterial.bKHR_materials_iridescence || RuntimeMaterial.bKHR_materials_sheen || RuntimeMaterial.bKHR_materials_volume)
{
bIsSimpleSlab = false;
}

EglTFRuntimeSubstrateMaterialType SubstrateMaterialType = RuntimeMaterial.bTwoSided ?
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleOpaqueTwoSided : EglTFRuntimeSubstrateMaterialType::OpaqueTwoSided) :
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleOpaque : EglTFRuntimeSubstrateMaterialType::Opaque);

if (RuntimeMaterial.bKHR_materials_transmission)
{
SubstrateMaterialType = RuntimeMaterial.bTwoSided ? EglTFRuntimeSubstrateMaterialType::TransmittanceTwoSided : EglTFRuntimeSubstrateMaterialType::Transmittance;
SubstrateMaterialType = RuntimeMaterial.bTwoSided ?
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleTransmittanceTwoSided : EglTFRuntimeSubstrateMaterialType::TransmittanceTwoSided) :
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleTransmittance : EglTFRuntimeSubstrateMaterialType::Transmittance);
}
else if (RuntimeMaterial.bTranslucent)
{
SubstrateMaterialType = RuntimeMaterial.bTwoSided ? EglTFRuntimeSubstrateMaterialType::AlphaCompositeTwoSided : EglTFRuntimeSubstrateMaterialType::AlphaComposite;
SubstrateMaterialType = RuntimeMaterial.bTwoSided ?
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleAlphaCompositeTwoSided : EglTFRuntimeSubstrateMaterialType::AlphaCompositeTwoSided) :
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleAlphaComposite : EglTFRuntimeSubstrateMaterialType::AlphaComposite);
}
else if (RuntimeMaterial.bMasked)
{
SubstrateMaterialType = RuntimeMaterial.bTwoSided ? EglTFRuntimeSubstrateMaterialType::MaskedTwoSided : EglTFRuntimeSubstrateMaterialType::Masked;
SubstrateMaterialType = RuntimeMaterial.bTwoSided ?
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleMaskedTwoSided : EglTFRuntimeSubstrateMaterialType::MaskedTwoSided) :
(bIsSimpleSlab ? EglTFRuntimeSubstrateMaterialType::SimpleMasked : EglTFRuntimeSubstrateMaterialType::Masked);
}

if (MaterialsConfig.SubstrateMaterials.Contains(SubstrateMaterialType))
Expand Down Expand Up @@ -956,6 +1002,23 @@ UMaterialInterface* FglTFRuntimeParser::BuildMaterial(const int32 Index, const F
TextureCompressionSettings::TC_Default, false);
}

ApplyMaterialFloatFactor(RuntimeMaterial.bKHR_materials_iridescence, "iridescenceFactor", RuntimeMaterial.IridescenceFactor);
ApplyMaterialFloatFactor(RuntimeMaterial.bKHR_materials_iridescence, "iridescenceIor", RuntimeMaterial.IridescenceIor);
ApplyMaterialFloatFactor(RuntimeMaterial.bKHR_materials_iridescence, "iridescenceThicknessMaximum", RuntimeMaterial.IridescenceThicknessMaximum);
ApplyMaterialFloatFactor(RuntimeMaterial.bKHR_materials_iridescence, "iridescenceThicknessMinimum", RuntimeMaterial.IridescenceThicknessMinimum);
if (RuntimeMaterial.bKHR_materials_iridescence)
{
ApplyMaterialTexture("iridescenceTexture", RuntimeMaterial.IridescenceTextureCache, RuntimeMaterial.IridescenceTextureMips,
RuntimeMaterial.IridescenceTextureSampler,
"iridescence", RuntimeMaterial.IridescenceTextureTransform,
TextureCompressionSettings::TC_Default, true);

ApplyMaterialTexture("iridescenceThicknessTexture", RuntimeMaterial.IridescenceThicknessTextureCache, RuntimeMaterial.IridescenceThicknessTextureMips,
RuntimeMaterial.IridescenceThicknessTextureSampler,
"iridescenceThickness", RuntimeMaterial.IridescenceThicknessTextureTransform,
TextureCompressionSettings::TC_Default, true);
}

ApplyMaterialFloatFactor(RuntimeMaterial.bKHR_materials_emissive_strength, "emissiveStrength", RuntimeMaterial.EmissiveStrength);

for (const TPair<FString, float>& Pair : MaterialsConfig.ScalarParamsOverrides)
Expand Down
28 changes: 28 additions & 0 deletions Source/glTFRuntime/Public/glTFRuntimeParser.h
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -437,6 +437,14 @@ enum class EglTFRuntimeMaterialType : uint8
UENUM()
enum class EglTFRuntimeSubstrateMaterialType : uint8
{
SimpleOpaque,
SimpleOpaqueTwoSided,
SimpleTransmittance,
SimpleTransmittanceTwoSided,
SimpleAlphaComposite,
SimpleAlphaCompositeTwoSided,
SimpleMasked,
SimpleMaskedTwoSided,
Opaque,
OpaqueTwoSided,
Transmittance,
Expand Down Expand Up @@ -2202,6 +2210,19 @@ struct FglTFRuntimeMaterial
FglTFRuntimeTextureTransform SheenRoughnessTextureTransform;
FglTFRuntimeTextureSampler SheenRoughnessTextureSampler;

bool bKHR_materials_iridescence;
double IridescenceFactor;
double IridescenceIor;
double IridescenceThicknessMaximum;
double IridescenceThicknessMinimum;
UTexture2D* IridescenceTextureCache;
TArray<FglTFRuntimeMipMap> IridescenceTextureMips;
FglTFRuntimeTextureSampler IridescenceTextureSampler;
FglTFRuntimeTextureTransform IridescenceTextureTransform;
UTexture2D* IridescenceThicknessTextureCache;
TArray<FglTFRuntimeMipMap> IridescenceThicknessTextureMips;
FglTFRuntimeTextureSampler IridescenceThicknessTextureSampler;
FglTFRuntimeTextureTransform IridescenceThicknessTextureTransform;

FglTFRuntimeMaterial()
{
Expand Down Expand Up @@ -2253,6 +2274,13 @@ struct FglTFRuntimeMaterial
SheenRoughnessFactor = 0;
SheenColorTextureCache = nullptr;
SheenRoughnessTextureCache = nullptr;
bKHR_materials_iridescence = false;
IridescenceFactor = 0;
IridescenceIor = 1.3;
IridescenceThicknessMaximum = 400;
IridescenceThicknessMinimum = 100;
IridescenceTextureCache = nullptr;
IridescenceThicknessTextureCache = nullptr;
}
};

Expand Down