Store property attributes in FCesiumPrimitiveMetadata

CHANGES.md

@@ -2,6 +2,17 @@
 
 ### ? - ?
 
+##### Breaking Changes :mega:
+
+- `FCesiumPrimitiveMetadata::GetPropertyAttributeIndices` is now deprecated. Use `GetPropertyAttributes` to directly get the `FCesiumPropertyAttribute`s instead.
+
+##### Additions :tada:
+
+- Added `FCesiumPropertyAttributeProperty` to represent glTF property attribute properties and `UCesiumPropertyAttributePropertyBlueprintLibrary` to retrieve their values.
+- Added `FCesiumPropertyAttribute` to represent glTF property attributes and `UCesiumPropertyAttributeBlueprintLibrary` to act upon them with Blueprints.
+- Added `UCesiumPrimitiveMetadataBlueprintLibrary::GetPropertyAttributes` to retrieve the property attributes from a `FCesiumPrimitiveMetadata`.
+- Added `UCesiumPropertyTexturePropertyBlueprintLibrary::GetInteger64`. Although 64-bit integers aren't directly supported by property textures, this enables the lossless retrieval of 32-bit unsigned integers.
+
 ##### Fixes :wrench:
 
 - Fixed error messages in the Unreal log about uninitialized fields in `FCesiumGeocoderServiceAttribution` and `FCesiumGeocoderServiceFeature`.

Source/CesiumRuntime/Private/CesiumGltfComponent.cpp

@@ -1093,7 +1093,7 @@ static void loadPrimitiveFeaturesMetadata(
       pFeatures ? FCesiumPrimitiveFeatures(model, primitive, *pFeatures)
                 : FCesiumPrimitiveFeatures();
   primitiveResult.Metadata =
-      pMetadata ? FCesiumPrimitiveMetadata(primitive, *pMetadata)
+      pMetadata ? FCesiumPrimitiveMetadata(model, primitive, *pMetadata)
                 : FCesiumPrimitiveMetadata();
 
   PRAGMA_DISABLE_DEPRECATION_WARNINGS

Source/CesiumRuntime/Private/CesiumPrimitiveMetadata.cpp

@@ -1,26 +1,51 @@
 // Copyright 2020-2024 CesiumGS, Inc. and Contributors
 
 #include "CesiumPrimitiveMetadata.h"
-#include "CesiumGltf/AccessorView.h"
-#include "CesiumGltf/ExtensionMeshPrimitiveExtStructuralMetadata.h"
-#include "CesiumGltf/Model.h"
 #include "CesiumGltfPrimitiveComponent.h"
+#include "CesiumPropertyAttribute.h"
+
+#include <CesiumGltf/ExtensionMeshPrimitiveExtStructuralMetadata.h>
+#include <CesiumGltf/ExtensionModelExtStructuralMetadata.h>
+#include <CesiumGltf/Model.h>
 
 static FCesiumPrimitiveMetadata EmptyPrimitiveMetadata;
 
 FCesiumPrimitiveMetadata::FCesiumPrimitiveMetadata(
-    const CesiumGltf::MeshPrimitive& Primitive,
-    const CesiumGltf::ExtensionMeshPrimitiveExtStructuralMetadata& Metadata)
-    : _propertyTextureIndices(), _propertyAttributeIndices() {
-  this->_propertyTextureIndices.Reserve(Metadata.propertyTextures.size());
-  for (const int64 propertyTextureIndex : Metadata.propertyTextures) {
+    const CesiumGltf::Model& model,
+    const CesiumGltf::MeshPrimitive& primitive,
+    const CesiumGltf::ExtensionMeshPrimitiveExtStructuralMetadata& metadata)
+    : _propertyTextureIndices(),
+      _propertyAttributes(),
+      _propertyAttributeIndices() {
+  this->_propertyTextureIndices.Reserve(metadata.propertyTextures.size());
+  for (const int64 propertyTextureIndex : metadata.propertyTextures) {
     this->_propertyTextureIndices.Emplace(propertyTextureIndex);
   }
 
-  this->_propertyAttributeIndices.Reserve(Metadata.propertyAttributes.size());
-  for (const int64 propertyAttributeIndex : Metadata.propertyAttributes) {
+  // For backwards compatibility with GetPropertyAttributeIndices().
+  this->_propertyAttributeIndices.Reserve(metadata.propertyAttributes.size());
+  for (const int64 propertyAttributeIndex : metadata.propertyAttributes) {
     this->_propertyAttributeIndices.Emplace(propertyAttributeIndex);
   }
+
+  const auto* pModelMetadata =
+      model.getExtension<CesiumGltf::ExtensionModelExtStructuralMetadata>();
+  if (!pModelMetadata) {
+    return;
+  }
+
+  for (const int64 propertyAttributeIndex : metadata.propertyAttributes) {
+    if (propertyAttributeIndex < 0 ||
+        propertyAttributeIndex >=
+            int64_t(pModelMetadata->propertyAttributes.size())) {
+      continue;
+    }
+
+    this->_propertyAttributes.Emplace(FCesiumPropertyAttribute(
+        model,
+        primitive,
+        pModelMetadata->propertyAttributes[propertyAttributeIndex]));
+  }
 }
 
 const FCesiumPrimitiveMetadata&
@@ -41,6 +66,12 @@ UCesiumPrimitiveMetadataBlueprintLibrary::GetPropertyTextureIndices(
   return PrimitiveMetadata._propertyTextureIndices;
 }
 
+const TArray<FCesiumPropertyAttribute>&
+UCesiumPrimitiveMetadataBlueprintLibrary::GetPropertyAttributes(
+    UPARAM(ref) const FCesiumPrimitiveMetadata& PrimitiveMetadata) {
+  return PrimitiveMetadata._propertyAttributes;
+}
+
 const TArray<int64>&
 UCesiumPrimitiveMetadataBlueprintLibrary::GetPropertyAttributeIndices(
     UPARAM(ref) const FCesiumPrimitiveMetadata& PrimitiveMetadata) {

Source/CesiumRuntime/Private/CesiumPropertyAttribute.cpp

@@ -0,0 +1,143 @@
+// Copyright 2020-2024 CesiumGS, Inc. and Contributors
+
+#include "CesiumPropertyAttribute.h"
+#include <CesiumGltf/PropertyAttributeView.h>
+
+static FCesiumPropertyAttributeProperty EmptyPropertyAttributeProperty;
+
+FCesiumPropertyAttribute::FCesiumPropertyAttribute(
+    const CesiumGltf::Model& model,
+    const CesiumGltf::MeshPrimitive& primitive,
+    const CesiumGltf::PropertyAttribute& propertyAttribute,
+    const TSharedPtr<FCesiumMetadataEnumCollection>& pEnumCollection)
+    : _status(
+          ECesiumPropertyAttributeStatus::ErrorInvalidPropertyAttributeClass),
+      _name(propertyAttribute.name.value_or("").c_str()),
+      _className(propertyAttribute.classProperty.c_str()),
+      _elementCount(0),
+      _properties() {
+  CesiumGltf::PropertyAttributeView propertyAttributeView{
+      model,
+      propertyAttribute};
+  switch (propertyAttributeView.status()) {
+  case CesiumGltf::PropertyAttributeViewStatus::Valid:
+    _status = ECesiumPropertyAttributeStatus::Valid;
+    break;
+  default:
+    // Status was already set in initializer list.
+    return;
+  }
+
+  const CesiumGltf::ExtensionModelExtStructuralMetadata* pExtension =
+      model.getExtension<CesiumGltf::ExtensionModelExtStructuralMetadata>();
+  // If there was no schema, we would've gotten ErrorMissingSchema for the
+  // propertyAttributeView status.
+  check(pExtension != nullptr && pExtension->schema != nullptr);
+
+  propertyAttributeView.forEachProperty(
+      primitive,
+      [&properties = _properties,
+       &elementCount = _elementCount,
+       &Schema = *pExtension->schema,
+       &propertyAttributeView,
+       &pEnumCollection](
+          const std::string& propertyName,
+          auto propertyValue) mutable {
+        FString key(UTF8_TO_TCHAR(propertyName.data()));
+        const CesiumGltf::ClassProperty* pClassProperty =
+            propertyAttributeView.getClassProperty(propertyName);
+        check(pClassProperty);
+
+        TSharedPtr<FCesiumMetadataEnum> pEnumDefinition(nullptr);
+        if (pEnumCollection.IsValid() && pClassProperty->enumType.has_value()) {
+          pEnumDefinition = pEnumCollection->Get(
+              FString(UTF8_TO_TCHAR(pClassProperty->enumType.value().c_str())));
+        }
+
+        if (elementCount == 0) {
+          // Use the first non-zero property size to compare against all the
+          // others.
+          elementCount = propertyValue.size();
+        }
+
+        if (propertyValue.size() > 0 && elementCount != propertyValue.size()) {
+          UE_LOG(
+              LogCesium,
+              Error,
+              TEXT(
+                  "The size of one or more property attribute properties does not match the others."));
+        }
+
+        properties.Add(
+            key,
+            FCesiumPropertyAttributeProperty(propertyValue, pEnumDefinition));
+      });
+}
+
+/*static*/ ECesiumPropertyAttributeStatus
+UCesiumPropertyAttributeBlueprintLibrary::GetPropertyAttributeStatus(
+    UPARAM(ref) const FCesiumPropertyAttribute& PropertyAttribute) {
+  return PropertyAttribute._status;
+}
+
+/*static*/ const FString&
+UCesiumPropertyAttributeBlueprintLibrary::GetPropertyAttributeName(
+    UPARAM(ref) const FCesiumPropertyAttribute& PropertyAttribute) {
+  return PropertyAttribute._name;
+}
+
+/*static*/ const TMap<FString, FCesiumPropertyAttributeProperty>&
+UCesiumPropertyAttributeBlueprintLibrary::GetProperties(
+    UPARAM(ref) const FCesiumPropertyAttribute& PropertyAttribute) {
+  return PropertyAttribute._properties;
+}
+
+/*static*/ const TArray<FString>
+UCesiumPropertyAttributeBlueprintLibrary::GetPropertyNames(
+    UPARAM(ref) const FCesiumPropertyAttribute& PropertyAttribute) {
+  TArray<FString> names;
+  PropertyAttribute._properties.GenerateKeyArray(names);
+  return names;
+}
+
+/*static*/ const FCesiumPropertyAttributeProperty&
+UCesiumPropertyAttributeBlueprintLibrary::FindProperty(
+    UPARAM(ref) const FCesiumPropertyAttribute& PropertyAttribute,
+    const FString& PropertyName) {
+  const FCesiumPropertyAttributeProperty* property =
+      PropertyAttribute._properties.Find(PropertyName);
+  return property ? *property : EmptyPropertyAttributeProperty;
+}
+
+/*static*/ TMap<FString, FCesiumMetadataValue>
+UCesiumPropertyAttributeBlueprintLibrary::GetMetadataValuesAtIndex(
+    UPARAM(ref) const FCesiumPropertyAttribute& PropertyAttribute,
+    int64 Index) {
+  TMap<FString, FCesiumMetadataValue> values;
+  if (Index < 0 || Index >= PropertyAttribute._elementCount) {
+    return values;
+  }
+
+  for (const auto& pair : PropertyAttribute._properties) {
+    const FCesiumPropertyAttributeProperty& property = pair.Value;
+    ECesiumPropertyAttributePropertyStatus status =
+        UCesiumPropertyAttributePropertyBlueprintLibrary::
+            GetPropertyAttributePropertyStatus(property);
+    if (status == ECesiumPropertyAttributePropertyStatus::Valid) {
+      values.Add(
+          pair.Key,
+          UCesiumPropertyAttributePropertyBlueprintLibrary::GetValue(
+              pair.Value,
+              Index));
+    } else if (
+        status ==
+        ECesiumPropertyAttributePropertyStatus::EmptyPropertyWithDefault) {
+      values.Add(
+          pair.Key,
+          UCesiumPropertyAttributePropertyBlueprintLibrary::GetDefaultValue(
+              pair.Value));
+    }
+  }
+
+  return values;
+}