初始提交: UE5.3项目基础框架

2025-10-14 11:14:54 +08:00
commit 721d9fd98e
5334 changed files with 316782 additions and 0 deletions
--- a/Plugins/CesiumForUnreal/Source/CesiumRuntime/Private/Tests/CesiumPrimitiveFeatures.spec.cpp
+++ b/Plugins/CesiumForUnreal/Source/CesiumRuntime/Private/Tests/CesiumPrimitiveFeatures.spec.cpp
@ -0,0 +1,752 @@
+// Copyright 2020-2024 CesiumGS, Inc. and Contributors
+
+#include "CesiumPrimitiveFeatures.h"
+#include "CesiumGltf/ExtensionExtMeshFeatures.h"
+#include "CesiumGltfSpecUtility.h"
+#include "Misc/AutomationTest.h"
+
+BEGIN_DEFINE_SPEC(
+    FCesiumPrimitiveFeaturesSpec,
+    "Cesium.Unit.PrimitiveFeatures",
+    EAutomationTestFlags::EditorContext | EAutomationTestFlags::ClientContext |
+        EAutomationTestFlags::ServerContext |
+        EAutomationTestFlags::CommandletContext |
+        EAutomationTestFlags::ProductFilter)
+CesiumGltf::Model model;
+CesiumGltf::MeshPrimitive* pPrimitive;
+CesiumGltf::ExtensionExtMeshFeatures* pExtension;
+END_DEFINE_SPEC(FCesiumPrimitiveFeaturesSpec)
+
+void FCesiumPrimitiveFeaturesSpec::Define() {
+  Describe("Constructor", [this]() {
+    BeforeEach([this]() {
+      model = CesiumGltf::Model();
+      CesiumGltf::Mesh& mesh = model.meshes.emplace_back();
+      pPrimitive = &mesh.primitives.emplace_back();
+      pExtension =
+          &pPrimitive->addExtension<CesiumGltf::ExtensionExtMeshFeatures>();
+    });
+
+    It("constructs with no feature ID sets", [this]() {
+      // This is technically disallowed by the spec, but just make sure it's
+      // handled reasonably.
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+      TArray<FCesiumFeatureIdSet> featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSets(
+              primitiveFeatures);
+      TestEqual("Number of FeatureIDSets", featureIDSets.Num(), 0);
+    });
+
+    It("constructs with single feature ID set", [this]() {
+      CesiumGltf::FeatureId& featureID = pExtension->featureIds.emplace_back();
+      featureID.featureCount = 10;
+
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+      const TArray<FCesiumFeatureIdSet>& featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSets(
+              primitiveFeatures);
+      TestEqual("Number of FeatureIDSets", featureIDSets.Num(), 1);
+
+      const FCesiumFeatureIdSet& featureIDSet = featureIDSets[0];
+      TestEqual(
+          "Feature Count",
+          UCesiumFeatureIdSetBlueprintLibrary::GetFeatureCount(featureIDSet),
+          static_cast<int64>(featureID.featureCount));
+      TestEqual(
+          "FeatureIDType",
+          UCesiumFeatureIdSetBlueprintLibrary::GetFeatureIDSetType(
+              featureIDSet),
+          ECesiumFeatureIdSetType::Implicit);
+    });
+
+    It("constructs with multiple feature ID sets", [this]() {
+      const std::vector<uint8_t> attributeIDs{0, 0, 0};
+      AddFeatureIDsAsAttributeToModel(model, *pPrimitive, attributeIDs, 1, 0);
+
+      const std::vector<uint8_t> textureIDs{1, 2, 3};
+      const std::vector<glm::vec2> texCoords{
+          glm::vec2(0, 0),
+          glm::vec2(0.34, 0),
+          glm::vec2(0.67, 0)};
+      AddFeatureIDsAsTextureToModel(
+          model,
+          *pPrimitive,
+          textureIDs,
+          3,
+          3,
+          1,
+          texCoords,
+          0);
+
+      CesiumGltf::FeatureId& implicitIDs =
+          pExtension->featureIds.emplace_back();
+      implicitIDs.featureCount = 3;
+
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+      const TArray<FCesiumFeatureIdSet>& featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSets(
+              primitiveFeatures);
+      TestEqual("Number of FeatureIDSets", featureIDSets.Num(), 3);
+
+      const std::vector<ECesiumFeatureIdSetType> expectedTypes{
+          ECesiumFeatureIdSetType::Attribute,
+          ECesiumFeatureIdSetType::Texture,
+          ECesiumFeatureIdSetType::Implicit};
+
+      for (size_t i = 0; i < featureIDSets.Num(); i++) {
+        const FCesiumFeatureIdSet& featureIDSet =
+            featureIDSets[static_cast<int32>(i)];
+        const CesiumGltf::FeatureId& gltfFeatureID = pExtension->featureIds[i];
+        TestEqual(
+            "Feature Count",
+            UCesiumFeatureIdSetBlueprintLibrary::GetFeatureCount(featureIDSet),
+            static_cast<int64>(gltfFeatureID.featureCount));
+        TestEqual(
+            "FeatureIDType",
+            UCesiumFeatureIdSetBlueprintLibrary::GetFeatureIDSetType(
+                featureIDSet),
+            expectedTypes[i]);
+      }
+    });
+  });
+
+  Describe("GetFeatureIDSetsOfType", [this]() {
+    BeforeEach([this]() {
+      model = CesiumGltf::Model();
+      CesiumGltf::Mesh& mesh = model.meshes.emplace_back();
+      pPrimitive = &mesh.primitives.emplace_back();
+      pExtension =
+          &pPrimitive->addExtension<CesiumGltf::ExtensionExtMeshFeatures>();
+
+      const std::vector<uint8_t> attributeIDs{0, 0, 0};
+      AddFeatureIDsAsAttributeToModel(model, *pPrimitive, attributeIDs, 1, 0);
+
+      const std::vector<uint8_t> textureIDs{1, 2, 3};
+      const std::vector<glm::vec2> texCoords{
+          glm::vec2(0, 0),
+          glm::vec2(0.34, 0),
+          glm::vec2(0.67, 0)};
+      AddFeatureIDsAsTextureToModel(
+          model,
+          *pPrimitive,
+          textureIDs,
+          3,
+          3,
+          1,
+          texCoords,
+          0);
+
+      CesiumGltf::FeatureId& implicitIDs =
+          pExtension->featureIds.emplace_back();
+      implicitIDs.featureCount = 3;
+    });
+
+    It("gets feature ID attribute", [this]() {
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+      const TArray<FCesiumFeatureIdSet> featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSetsOfType(
+              primitiveFeatures,
+              ECesiumFeatureIdSetType::Attribute);
+      TestEqual("Number of FeatureIDSets", featureIDSets.Num(), 1);
+
+      const FCesiumFeatureIdSet& featureIDSet = featureIDSets[0];
+      TestEqual(
+          "FeatureIDType",
+          UCesiumFeatureIdSetBlueprintLibrary::GetFeatureIDSetType(
+              featureIDSet),
+          ECesiumFeatureIdSetType::Attribute);
+
+      const FCesiumFeatureIdAttribute& attribute =
+          UCesiumFeatureIdSetBlueprintLibrary::GetAsFeatureIDAttribute(
+              featureIDSet);
+      TestEqual(
+          "AttributeStatus",
+          UCesiumFeatureIdAttributeBlueprintLibrary::
+              GetFeatureIDAttributeStatus(attribute),
+          ECesiumFeatureIdAttributeStatus::Valid);
+    });
+
+    It("gets feature ID texture", [this]() {
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+      const TArray<FCesiumFeatureIdSet> featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSetsOfType(
+              primitiveFeatures,
+              ECesiumFeatureIdSetType::Texture);
+      TestEqual("Number of FeatureIDSets", featureIDSets.Num(), 1);
+
+      const FCesiumFeatureIdSet& featureIDSet = featureIDSets[0];
+      TestEqual(
+          "FeatureIDType",
+          UCesiumFeatureIdSetBlueprintLibrary::GetFeatureIDSetType(
+              featureIDSet),
+          ECesiumFeatureIdSetType::Texture);
+
+      const FCesiumFeatureIdTexture& texture =
+          UCesiumFeatureIdSetBlueprintLibrary::GetAsFeatureIDTexture(
+              featureIDSet);
+      TestEqual(
+          "TextureStatus",
+          UCesiumFeatureIdTextureBlueprintLibrary::GetFeatureIDTextureStatus(
+              texture),
+          ECesiumFeatureIdTextureStatus::Valid);
+    });
+
+    It("gets implicit feature ID", [this]() {
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+      const TArray<FCesiumFeatureIdSet> featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSetsOfType(
+              primitiveFeatures,
+              ECesiumFeatureIdSetType::Implicit);
+      TestEqual("Number of FeatureIDSets", featureIDSets.Num(), 1);
+
+      const FCesiumFeatureIdSet& featureIDSet = featureIDSets[0];
+      TestEqual(
+          "FeatureIDType",
+          UCesiumFeatureIdSetBlueprintLibrary::GetFeatureIDSetType(
+              featureIDSet),
+          ECesiumFeatureIdSetType::Implicit);
+    });
+  });
+
+  Describe("GetFirstVertexFromFace", [this]() {
+    BeforeEach([this]() {
+      model = CesiumGltf::Model();
+      CesiumGltf::Mesh& mesh = model.meshes.emplace_back();
+      pPrimitive = &mesh.primitives.emplace_back();
+      pExtension =
+          &pPrimitive->addExtension<CesiumGltf::ExtensionExtMeshFeatures>();
+    });
+
+    It("returns -1 for out-of-bounds face index", [this]() {
+      const std::vector<uint8_t> indices{0, 1, 2, 0, 2, 3};
+      CreateIndicesForPrimitive(
+          model,
+          *pPrimitive,
+          CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+          indices);
+
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+      TestEqual(
+          "VertexIndexForNegativeFace",
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFirstVertexFromFace(
+              primitiveFeatures,
+              -1),
+          -1);
+      TestEqual(
+          "VertexIndexForOutOfBoundsFace",
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFirstVertexFromFace(
+              primitiveFeatures,
+              2),
+          -1);
+    });
+
+    It("returns correct value for primitive without indices", [this]() {
+      CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+      accessor.count = 9;
+      const int64 numFaces = accessor.count / 3;
+
+      pPrimitive->attributes.insert(
+          {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+      for (int64 i = 0; i < numFaces; i++) {
+        TestEqual(
+            "VertexIndexForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFirstVertexFromFace(
+                primitiveFeatures,
+                i),
+            i * 3);
+      }
+    });
+
+    It("returns correct value for primitive with indices", [this]() {
+      const std::vector<uint8_t> indices{0, 1, 2, 0, 2, 3, 4, 5, 6};
+      CreateIndicesForPrimitive(
+          model,
+          *pPrimitive,
+          CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+          indices);
+
+      CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+      accessor.count = 7;
+      pPrimitive->attributes.insert(
+          {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+      const size_t numFaces = indices.size() / 3;
+      for (size_t i = 0; i < numFaces; i++) {
+        TestEqual(
+            "VertexIndexForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFirstVertexFromFace(
+                primitiveFeatures,
+                static_cast<int64>(i)),
+            indices[i * 3]);
+      }
+    });
+  });
+
+  Describe("GetFeatureIDFromFace", [this]() {
+    BeforeEach([this]() {
+      model = CesiumGltf::Model();
+      CesiumGltf::Mesh& mesh = model.meshes.emplace_back();
+      pPrimitive = &mesh.primitives.emplace_back();
+      pExtension =
+          &pPrimitive->addExtension<CesiumGltf::ExtensionExtMeshFeatures>();
+    });
+
+    It("returns -1 for primitive with empty feature ID sets", [this]() {
+      const std::vector<uint8_t> indices{0, 1, 2, 0, 2, 3};
+      CreateIndicesForPrimitive(
+          model,
+          *pPrimitive,
+          CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+          indices);
+
+      CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+      accessor.count = 6;
+      pPrimitive->attributes.insert(
+          {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+      // Adds empty feature ID.
+      pExtension->featureIds.emplace_back();
+
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+      const TArray<FCesiumFeatureIdSet>& featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSets(
+              primitiveFeatures);
+
+      TestEqual(
+          "FeatureIDForPrimitiveWithNoSets",
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+              primitiveFeatures,
+              0),
+          -1);
+    });
+
+    It("returns -1 for out of bounds feature ID set index", [this]() {
+      std::vector<uint8_t> attributeIDs{1, 1, 1, 1, 0, 0, 0};
+      AddFeatureIDsAsAttributeToModel(model, *pPrimitive, attributeIDs, 2, 0);
+
+      const std::vector<uint8_t> indices{0, 1, 2, 0, 2, 3, 4, 5, 6};
+      CreateIndicesForPrimitive(
+          model,
+          *pPrimitive,
+          CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+          indices);
+
+      CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+      accessor.count = 7;
+      pPrimitive->attributes.insert(
+          {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+      FCesiumPrimitiveFeatures primitiveFeatures =
+          FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+      const TArray<FCesiumFeatureIdSet>& featureIDSets =
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSets(
+              primitiveFeatures);
+
+      TestEqual(
+          "FeatureIDForOutOfBoundsSetIndex",
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+              primitiveFeatures,
+              0,
+              -1),
+          -1);
+      TestEqual(
+          "FeatureIDForOutOfBoundsSetIndex",
+          UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+              primitiveFeatures,
+              0,
+              2),
+          -1);
+    });
+
+    Describe("FeatureIDAttribute", [this]() {
+      It("returns -1 for out-of-bounds face index", [this]() {
+        std::vector<uint8_t> attributeIDs{1, 1, 1};
+        AddFeatureIDsAsAttributeToModel(model, *pPrimitive, attributeIDs, 1, 0);
+
+        const std::vector<uint8_t> indices{0, 1, 2};
+        CreateIndicesForPrimitive(
+            model,
+            *pPrimitive,
+            CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+            indices);
+
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 3;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        TestEqual(
+            "FeatureIDForNegativeFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                -1),
+            -1);
+        TestEqual(
+            "FeatureIDForOutOfBoundsFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                2),
+            -1);
+      });
+
+      It("returns correct values for primitive without indices", [this]() {
+        std::vector<uint8_t> attributeIDs{1, 1, 1, 2, 2, 2, 0, 0, 0};
+        AddFeatureIDsAsAttributeToModel(model, *pPrimitive, attributeIDs, 3, 0);
+
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 9;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        const size_t numFaces = static_cast<size_t>(accessor.count / 3);
+        for (size_t i = 0; i < numFaces; i++) {
+          TestEqual(
+              "FeatureIDForFace",
+              UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                  primitiveFeatures,
+                  static_cast<int64>(i)),
+              attributeIDs[i * 3]);
+        }
+      });
+
+      It("returns correct values for primitive with indices", [this]() {
+        std::vector<uint8_t> attributeIDs{1, 1, 1, 1, 0, 0, 0};
+        AddFeatureIDsAsAttributeToModel(model, *pPrimitive, attributeIDs, 2, 0);
+
+        const std::vector<uint8_t> indices{0, 1, 2, 0, 2, 3, 4, 5, 6};
+        CreateIndicesForPrimitive(
+            model,
+            *pPrimitive,
+            CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+            indices);
+
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 7;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        const size_t numFaces = indices.size() / 3;
+        for (size_t i = 0; i < numFaces; i++) {
+          TestEqual(
+              "FeatureIDForFace",
+              UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                  primitiveFeatures,
+                  static_cast<int64>(i)),
+              attributeIDs[i * 3]);
+        }
+      });
+    });
+
+    Describe("FeatureIDTexture", [this]() {
+      It("returns -1 for out-of-bounds face index", [this]() {
+        const std::vector<uint8_t> textureIDs{0};
+        const std::vector<glm::vec2> texCoords{
+            glm::vec2(0, 0),
+            glm::vec2(0, 0),
+            glm::vec2(0, 0)};
+        AddFeatureIDsAsTextureToModel(
+            model,
+            *pPrimitive,
+            textureIDs,
+            4,
+            4,
+            1,
+            texCoords,
+            0);
+
+        const std::vector<uint8_t> indices{0, 1, 2};
+        CreateIndicesForPrimitive(
+            model,
+            *pPrimitive,
+            CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+            indices);
+
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 3;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        TestEqual(
+            "FeatureIDForNegativeFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                -1),
+            -1);
+        TestEqual(
+            "FeatureIDForOutOfBoundsFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                2),
+            -1);
+      });
+
+      It("returns correct values for primitive without indices", [this]() {
+        const std::vector<uint8_t> textureIDs{0, 1, 2, 3};
+        const std::vector<glm::vec2> texCoords{
+            glm::vec2(0, 0),
+            glm::vec2(0, 0),
+            glm::vec2(0, 0),
+            glm::vec2(0.75, 0),
+            glm::vec2(0.75, 0),
+            glm::vec2(0.75, 0)};
+        AddFeatureIDsAsTextureToModel(
+            model,
+            *pPrimitive,
+            textureIDs,
+            4,
+            4,
+            1,
+            texCoords,
+            0);
+
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 6;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                0),
+            0);
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                1),
+            3);
+      });
+
+      It("returns correct values for primitive with indices", [this]() {
+        const std::vector<uint8_t> textureIDs{0, 1, 2, 3};
+        const std::vector<glm::vec2> texCoords{
+            glm::vec2(0, 0),
+            glm::vec2(0.25, 0),
+            glm::vec2(0.5, 0),
+            glm::vec2(0.75, 0)};
+        AddFeatureIDsAsTextureToModel(
+            model,
+            *pPrimitive,
+            textureIDs,
+            4,
+            4,
+            1,
+            texCoords,
+            0);
+
+        const std::vector<uint8_t> indices{0, 1, 2, 2, 0, 3};
+        CreateIndicesForPrimitive(
+            model,
+            *pPrimitive,
+            CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+            indices);
+
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 4;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                0),
+            0);
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                1),
+            2);
+      });
+    });
+
+    Describe("ImplicitFeatureIDs", [this]() {
+      BeforeEach([this]() {
+        CesiumGltf::FeatureId& implicitIDs =
+            pExtension->featureIds.emplace_back();
+        implicitIDs.featureCount = 6;
+      });
+
+      It("returns -1 for out-of-bounds face index", [this]() {
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 6;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        TestEqual(
+            "FeatureIDForNegativeFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                -1),
+            -1);
+        TestEqual(
+            "FeatureIDForOutOfBoundsFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                10),
+            -1);
+      });
+
+      It("returns correct values for primitive without indices", [this]() {
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 6;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                0),
+            0);
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                1),
+            3);
+      });
+
+      It("returns correct values for primitive with indices", [this]() {
+        const std::vector<uint8_t> indices{2, 1, 0, 3, 4, 5};
+        CreateIndicesForPrimitive(
+            model,
+            *pPrimitive,
+            CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+            indices);
+
+        CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+        accessor.count = 4;
+        pPrimitive->attributes.insert(
+            {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+        FCesiumPrimitiveFeatures primitiveFeatures =
+            FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                0),
+            2);
+        TestEqual(
+            "FeatureIDForFace",
+            UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                primitiveFeatures,
+                1),
+            3);
+      });
+    });
+
+    It("gets feature ID from correct set with specified feature ID set index",
+       [this]() {
+         // First feature ID set is attribute
+         std::vector<uint8_t> attributeIDs{1, 1, 1, 1, 0, 0, 0};
+         AddFeatureIDsAsAttributeToModel(
+             model,
+             *pPrimitive,
+             attributeIDs,
+             2,
+             0);
+
+         const std::vector<uint8_t> indices{0, 1, 2, 0, 2, 3, 4, 5, 6};
+         CreateIndicesForPrimitive(
+             model,
+             *pPrimitive,
+             CesiumGltf::AccessorSpec::ComponentType::UNSIGNED_BYTE,
+             indices);
+
+         CesiumGltf::Accessor& accessor = model.accessors.emplace_back();
+         accessor.count = 7;
+         pPrimitive->attributes.insert(
+             {"POSITION", static_cast<int32_t>(model.accessors.size() - 1)});
+
+         // Second feature ID set is implicit
+         CesiumGltf::FeatureId& implicitIDs =
+             pExtension->featureIds.emplace_back();
+         implicitIDs.featureCount = 7;
+
+         FCesiumPrimitiveFeatures primitiveFeatures =
+             FCesiumPrimitiveFeatures(model, *pPrimitive, *pExtension);
+
+         const TArray<FCesiumFeatureIdSet>& featureIDSets =
+             UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDSets(
+                 primitiveFeatures);
+         TestEqual("FeatureIDSetCount", featureIDSets.Num(), 2);
+
+         int64 setIndex = 0;
+         for (size_t index = 0; index < indices.size(); index += 3) {
+           std::string label("FeatureIDAttribute" + std::to_string(index));
+           int64 faceIndex = static_cast<int64>(index) / 3;
+           int64 featureID = static_cast<int64>(attributeIDs[indices[index]]);
+           TestEqual(
+               FString(label.c_str()),
+               UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                   primitiveFeatures,
+                   faceIndex,
+                   setIndex),
+               featureID);
+         }
+
+         setIndex = 1;
+         for (size_t index = 0; index < indices.size(); index += 3) {
+           std::string label("ImplicitFeatureID" + std::to_string(index));
+           int64 faceIndex = static_cast<int64>(index) / 3;
+           int64 featureID = static_cast<int64>(indices[index]);
+           TestEqual(
+               FString(label.c_str()),
+               UCesiumPrimitiveFeaturesBlueprintLibrary::GetFeatureIDFromFace(
+                   primitiveFeatures,
+                   faceIndex,
+                   setIndex),
+               featureID);
+         }
+       });
+  });
+}