Add test for the mesh optimizer's ability to weld nearby vertices

Signed-off-by: Chris Burel <burelc@amazon.com>

Code/Tools/SceneAPI/SceneData/Groups/MeshGroup.h

@@ -29,27 +29,27 @@ namespace AZ
         }
         namespace SceneData
         {
-            class MeshGroup
+            class SCENE_DATA_CLASS MeshGroup
                 : public DataTypes::IMeshGroup
             {
             public:
                 AZ_RTTI(MeshGroup, "{07B356B7-3635-40B5-878A-FAC4EFD5AD86}", DataTypes::IMeshGroup);
                 AZ_CLASS_ALLOCATOR(MeshGroup, SystemAllocator, 0)
 
-                MeshGroup();
-                ~MeshGroup() override = default;
+                SCENE_DATA_API MeshGroup();
+                SCENE_DATA_API ~MeshGroup() override = default;
 
-                const AZStd::string& GetName() const override;
-                void SetName(const AZStd::string& name);
-                void SetName(AZStd::string&& name) override;
-                const Uuid& GetId() const override;
-                void OverrideId(const Uuid& id) override;
+                SCENE_DATA_API const AZStd::string& GetName() const override;
+                SCENE_DATA_API void SetName(const AZStd::string& name);
+                SCENE_DATA_API void SetName(AZStd::string&& name) override;
+                SCENE_DATA_API const Uuid& GetId() const override;
+                SCENE_DATA_API void OverrideId(const Uuid& id) override;
 
-                Containers::RuleContainer& GetRuleContainer() override;
-                const Containers::RuleContainer& GetRuleContainerConst() const override;
+                SCENE_DATA_API Containers::RuleContainer& GetRuleContainer() override;
+                SCENE_DATA_API const Containers::RuleContainer& GetRuleContainerConst() const override;
 
-                DataTypes::ISceneNodeSelectionList& GetSceneNodeSelectionList() override;
-                const DataTypes::ISceneNodeSelectionList& GetSceneNodeSelectionList() const override;
+                SCENE_DATA_API DataTypes::ISceneNodeSelectionList& GetSceneNodeSelectionList() override;
+                SCENE_DATA_API const DataTypes::ISceneNodeSelectionList& GetSceneNodeSelectionList() const override;
 
                 static void Reflect(AZ::ReflectContext* context);
                 static bool VersionConverter(SerializeContext& context, SerializeContext::DataElementNode& classElement);

Gems/SceneProcessing/Code/CMakeLists.txt

@@ -113,6 +113,7 @@ if(PAL_TRAIT_BUILD_TESTS_SUPPORTED)
                 PRIVATE
                     Gem::SceneProcessing.Editor.Static
                     AZ::AzTest
+                    AZ::SceneData
         )
         ly_add_googletest(
             NAME Gem::SceneProcessing.Editor.Tests

Gems/SceneProcessing/Code/Tests/MeshBuilder/MeshOptimizerComponentTests.cpp

@@ -0,0 +1,100 @@
+/*
+ * Copyright (c) Contributors to the Open 3D Engine Project. For complete copyright and license terms please see the LICENSE at the root of this distribution.
+ *
+ * SPDX-License-Identifier: Apache-2.0 OR MIT
+ *
+ */
+
+#include <gtest/gtest.h>
+
+#include <AzCore/Component/ComponentApplication.h>
+#include <AzCore/Component/Entity.h>
+#include <AzCore/Jobs/JobManagerComponent.h>
+#include <AzCore/Memory/MemoryComponent.h>
+#include <AzCore/UnitTest/TestTypes.h>
+#include <AzCore/std/smart_ptr/shared_ptr.h>
+#include <AzCore/std/smart_ptr/unique_ptr.h>
+#include <SceneAPI/SceneCore/Containers/Scene.h>
+#include <SceneAPI/SceneCore/Containers/SceneGraph.h>
+#include <SceneAPI/SceneCore/Events/GenerateEventContext.h>
+#include <SceneAPI/SceneCore/Utilities/SceneGraphSelector.h>
+#include <SceneAPI/SceneData/GraphData/MeshData.h>
+#include <SceneAPI/SceneData/Groups/MeshGroup.h>
+#include <Generation/Components/MeshOptimizer/MeshOptimizerComponent.h>
+
+#include <InitSceneAPIFixture.h>
+
+namespace SceneProcessing
+{
+    using VertexDeduplicationFixture = SceneProcessing::InitSceneAPIFixture;
+
+    TEST_F(VertexDeduplicationFixture, CanDeduplicateVertices)
+    {
+        AZ::ComponentApplication app;
+        AZ::Entity* systemEntity = app.Create({}, {});
+        systemEntity->AddComponent(aznew AZ::MemoryComponent());
+        systemEntity->AddComponent(aznew AZ::JobManagerComponent());
+        systemEntity->Init();
+        systemEntity->Activate();
+
+        AZ::SceneAPI::Containers::Scene scene("testScene");
+        AZ::SceneAPI::Containers::SceneGraph& graph = scene.GetGraph();
+
+        // Create a simple plane with 2 triangles, 6 total vertices, 2 shared vertices
+        // 0 --- 1
+        // |   / |
+        // |  /  |
+        // | /   |
+        // 2 --- 3
+        const AZStd::array planeVertexPositions = {
+            AZ::Vector3{0.0f, 0.0f, 0.0f},
+            AZ::Vector3{0.0f, 0.0f, 1.0f},
+            AZ::Vector3{1.0f, 0.0f, 1.0f},
+            AZ::Vector3{1.0f, 0.0f, 1.0f},
+            AZ::Vector3{1.0f, 0.0f, 0.0f},
+            AZ::Vector3{0.0f, 0.0f, 0.0f},
+        };
+        {
+            auto mesh = AZStd::make_unique<AZ::SceneData::GraphData::MeshData>();
+            {
+                int i = 0;
+                for (const AZ::Vector3& position : planeVertexPositions)
+                {
+                    mesh->AddPosition(position);
+                    mesh->AddNormal(AZ::Vector3::CreateAxisY());
+
+                    // This assumes that the data coming from the import process gives a unique control point
+                    // index to every vertex. This follows the behavior of the AssImp library.
+                    mesh->SetVertexIndexToControlPointIndexMap(i, i);
+                    ++i;
+                }
+            }
+            mesh->AddFace({0, 1, 2}, 0);
+            mesh->AddFace({3, 4, 5}, 0);
+
+            // The original source mesh should have 6 vertices
+            EXPECT_EQ(mesh->GetVertexCount(), planeVertexPositions.size());
+
+            graph.AddChild(graph.GetRoot(), "testMesh", AZStd::move(mesh));
+        }
+
+        auto meshGroup = AZStd::make_unique<AZ::SceneAPI::SceneData::MeshGroup>();
+        meshGroup->GetSceneNodeSelectionList().AddSelectedNode("testMesh");
+        scene.GetManifest().AddEntry(AZStd::move(meshGroup));
+
+        AZ::SceneGenerationComponents::MeshOptimizerComponent component;
+        AZ::SceneAPI::Events::GenerateSimplificationEventContext context(scene, "pc");
+        component.OptimizeMeshes(context);
+
+        AZ::SceneAPI::Containers::SceneGraph::NodeIndex optimizedNodeIndex = graph.Find(AZStd::string("testMesh").append(AZ::SceneAPI::Utilities::OptimizedMeshSuffix));
+        ASSERT_TRUE(optimizedNodeIndex.IsValid()) << "Mesh optimizer did not add an optimized version of the mesh";
+
+        const auto& optimizedMesh = AZStd::rtti_pointer_cast<AZ::SceneAPI::DataTypes::IMeshData>(graph.GetNodeContent(optimizedNodeIndex));
+        ASSERT_TRUE(optimizedMesh);
+
+        // The optimized mesh should have 4 vertices, the 2 shared vertices are welded together
+        EXPECT_EQ(optimizedMesh->GetVertexCount(), 4);
+
+        systemEntity->Deactivate();
+    }
+} // namespace SceneProcessing

Gems/SceneProcessing/Code/sceneprocessing_editor_tests_files.cmake

@@ -8,6 +8,7 @@
 
 set(FILES
     Tests/InitSceneAPIFixture.h
+    Tests/MeshBuilder/MeshOptimizerComponentTests.cpp
     Tests/MeshBuilder/MeshBuilderTests.cpp
     Tests/MeshBuilder/MeshVerticesTests.cpp
     Tests/MeshBuilder/SkinInfluencesTests.cpp