[ue4] Black Spots and Normal Flipping Bug Fixes By CCW Resolve (Old Title : Normal Generation Improvement) (#2096)

* [ue4] Normal Generation Improvement

All the vertex normals now face correct direction. It will prevent some of the flicker in some occasions.

* [ue4] A Huge Rendering Improvement

A really huge upgrade for the rendering.
Now the renderer can resolving CCW of the triangles to remove the black spot of some parts, and it now has much more simple normal generation.
There is no need to restrict the movement of the joint / bone to avoid some ugly black spots being rendered from now, just do it without even thinking about it!
And also the flicking bug that caused by the normal flipping bug has been fixed with it, so now you can use lit material more practically with spine. Try to create some cool scenes with a great light setting!

spine-ue4/Plugins/SpinePlugin/Source/SpinePlugin/Private/SpineSkeletonRendererComponent.cpp

@@ -1,371 +1,403 @@
-/******************************************************************************
- * Spine Runtimes License Agreement
- * Last updated January 1, 2020. Replaces all prior versions.
- *
- * Copyright (c) 2013-2020, Esoteric Software LLC
- *
- * Integration of the Spine Runtimes into software or otherwise creating
- * derivative works of the Spine Runtimes is permitted under the terms and
- * conditions of Section 2 of the Spine Editor License Agreement:
- * http://esotericsoftware.com/spine-editor-license
- *
- * Otherwise, it is permitted to integrate the Spine Runtimes into software
- * or otherwise create derivative works of the Spine Runtimes (collectively,
- * "Products"), provided that each user of the Products must obtain their own
- * Spine Editor license and redistribution of the Products in any form must
- * include this license and copyright notice.
- *
- * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
- * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
- * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
- * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
- * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
- * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
- * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
- * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *****************************************************************************/
-
-#include "Engine.h"
-#include "SpinePluginPrivatePCH.h"
-#include "spine/spine.h"
-#include <stdlib.h>
-
-#define LOCTEXT_NAMESPACE "Spine"
-
-using namespace spine;
-
-USpineSkeletonRendererComponent::USpineSkeletonRendererComponent(const FObjectInitializer &ObjectInitializer)
-	: UProceduralMeshComponent(ObjectInitializer) {
-	PrimaryComponentTick.bCanEverTick = true;
-	bTickInEditor = true;
-	bAutoActivate = true;
-
-	static ConstructorHelpers::FObjectFinder<UMaterialInterface> NormalMaterialRef(TEXT("/SpinePlugin/SpineUnlitNormalMaterial"));
-	NormalBlendMaterial = NormalMaterialRef.Object;
-
-	static ConstructorHelpers::FObjectFinder<UMaterialInterface> AdditiveMaterialRef(TEXT("/SpinePlugin/SpineUnlitAdditiveMaterial"));
-	AdditiveBlendMaterial = AdditiveMaterialRef.Object;
-
-	static ConstructorHelpers::FObjectFinder<UMaterialInterface> MultiplyMaterialRef(TEXT("/SpinePlugin/SpineUnlitMultiplyMaterial"));
-	MultiplyBlendMaterial = MultiplyMaterialRef.Object;
-
-	static ConstructorHelpers::FObjectFinder<UMaterialInterface> ScreenMaterialRef(TEXT("/SpinePlugin/SpineUnlitScreenMaterial"));
-	ScreenBlendMaterial = ScreenMaterialRef.Object;
-
-	TextureParameterName = FName(TEXT("SpriteTexture"));
-
-	worldVertices.ensureCapacity(1024 * 2);
-}
-
-void USpineSkeletonRendererComponent::FinishDestroy() {
-	Super::FinishDestroy();
-}
-
-void USpineSkeletonRendererComponent::BeginPlay() {
-	Super::BeginPlay();
-}
-
-void USpineSkeletonRendererComponent::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction *ThisTickFunction) {
-	Super::TickComponent(DeltaTime, TickType, ThisTickFunction);
-
-	AActor *owner = GetOwner();
-	if (owner) {
-		UClass *skeletonClass = USpineSkeletonComponent::StaticClass();
-		USpineSkeletonComponent *skeleton = Cast<USpineSkeletonComponent>(owner->GetComponentByClass(skeletonClass));
-
-		UpdateRenderer(skeleton);
-	}
-}
-
-void USpineSkeletonRendererComponent::UpdateRenderer(USpineSkeletonComponent *skeleton) {
-	if (skeleton && !skeleton->IsBeingDestroyed() && skeleton->GetSkeleton() && skeleton->Atlas) {
-		skeleton->GetSkeleton()->getColor().set(Color.R, Color.G, Color.B, Color.A);
-
-		if (atlasNormalBlendMaterials.Num() != skeleton->Atlas->atlasPages.Num()) {
-			atlasNormalBlendMaterials.SetNum(0);
-			pageToNormalBlendMaterial.Empty();
-			atlasAdditiveBlendMaterials.SetNum(0);
-			pageToAdditiveBlendMaterial.Empty();
-			atlasMultiplyBlendMaterials.SetNum(0);
-			pageToMultiplyBlendMaterial.Empty();
-			atlasScreenBlendMaterials.SetNum(0);
-			pageToScreenBlendMaterial.Empty();
-
-			for (int i = 0; i < skeleton->Atlas->atlasPages.Num(); i++) {
-				AtlasPage *currPage = skeleton->Atlas->GetAtlas()->getPages()[i];
-
-				UMaterialInstanceDynamic *material = UMaterialInstanceDynamic::Create(NormalBlendMaterial, this);
-				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
-				atlasNormalBlendMaterials.Add(material);
-				pageToNormalBlendMaterial.Add(currPage, material);
-
-				material = UMaterialInstanceDynamic::Create(AdditiveBlendMaterial, this);
-				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
-				atlasAdditiveBlendMaterials.Add(material);
-				pageToAdditiveBlendMaterial.Add(currPage, material);
-
-				material = UMaterialInstanceDynamic::Create(MultiplyBlendMaterial, this);
-				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
-				atlasMultiplyBlendMaterials.Add(material);
-				pageToMultiplyBlendMaterial.Add(currPage, material);
-
-				material = UMaterialInstanceDynamic::Create(ScreenBlendMaterial, this);
-				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
-				atlasScreenBlendMaterials.Add(material);
-				pageToScreenBlendMaterial.Add(currPage, material);
-			}
-		} else {
-			pageToNormalBlendMaterial.Empty();
-			pageToAdditiveBlendMaterial.Empty();
-			pageToMultiplyBlendMaterial.Empty();
-			pageToScreenBlendMaterial.Empty();
-
-			for (int i = 0; i < skeleton->Atlas->atlasPages.Num(); i++) {
-				AtlasPage *currPage = skeleton->Atlas->GetAtlas()->getPages()[i];
-				UTexture2D *texture = skeleton->Atlas->atlasPages[i];
-
-				UpdateRendererMaterial(currPage, texture, atlasNormalBlendMaterials[i], NormalBlendMaterial, pageToNormalBlendMaterial);
-				UpdateRendererMaterial(currPage, texture, atlasAdditiveBlendMaterials[i], AdditiveBlendMaterial, pageToAdditiveBlendMaterial);
-				UpdateRendererMaterial(currPage, texture, atlasMultiplyBlendMaterials[i], MultiplyBlendMaterial, pageToMultiplyBlendMaterial);
-				UpdateRendererMaterial(currPage, texture, atlasScreenBlendMaterials[i], ScreenBlendMaterial, pageToScreenBlendMaterial);
-			}
-		}
-		UpdateMesh(skeleton->GetSkeleton());
-	} else {
-		ClearAllMeshSections();
-	}
-}
-
-void USpineSkeletonRendererComponent::UpdateRendererMaterial(spine::AtlasPage *CurrentPage, UTexture2D *Texture,
-															 UMaterialInstanceDynamic *&CurrentInstance, UMaterialInterface *ParentMaterial,
-															 TMap<spine::AtlasPage *, UMaterialInstanceDynamic *> &PageToBlendMaterial) {
-
-	UTexture *oldTexture = nullptr;
-	if (!CurrentInstance || !CurrentInstance->GetTextureParameterValue(TextureParameterName, oldTexture) ||
-		oldTexture != Texture || CurrentInstance->Parent != ParentMaterial) {
-
-		UMaterialInstanceDynamic *material = UMaterialInstanceDynamic::Create(ParentMaterial, this);
-		material->SetTextureParameterValue(TextureParameterName, Texture);
-		CurrentInstance = material;
-	}
-	PageToBlendMaterial.Add(CurrentPage, CurrentInstance);
-}
-
-void USpineSkeletonRendererComponent::Flush(int &Idx, TArray<FVector> &Vertices, TArray<int32> &Indices, TArray<FVector> &Normals, TArray<FVector2D> &Uvs, TArray<FColor> &Colors, TArray<FVector> &Colors2, UMaterialInstanceDynamic *Material) {
-	if (Vertices.Num() == 0) return;
-	SetMaterial(Idx, Material);
-
-	bool bShouldCreateCollision = false;
-	if (bCreateCollision) {
-		UWorld* world = GetWorld();
-		if (world && world->IsGameWorld()) {
-			bShouldCreateCollision = true;
-		}
-	}
-	
-	GetBodySetup()->bGenerateMirroredCollision = GetComponentScale().X < 0 || GetComponentScale().Y < 0 || GetComponentScale().Z < 0;
-	CreateMeshSection(Idx, Vertices, Indices, Normals, Uvs, Colors, TArray<FProcMeshTangent>(), bShouldCreateCollision);
-
-	Vertices.SetNum(0);
-	Indices.SetNum(0);
-	Normals.SetNum(0);
-	Uvs.SetNum(0);
-	Colors.SetNum(0);
-	Colors2.SetNum(0);
-	Idx++;
-}
-
-void USpineSkeletonRendererComponent::UpdateMesh(Skeleton *Skeleton) {
-	TArray<FVector> vertices;
-	TArray<int32> indices;
-	TArray<FVector> normals;
-	TArray<FVector2D> uvs;
-	TArray<FColor> colors;
-	TArray<FVector> darkColors;
-
-	int idx = 0;
-	int meshSection = 0;
-	UMaterialInstanceDynamic *lastMaterial = nullptr;
-
-	ClearAllMeshSections();
-
-	// Early out if skeleton is invisible
-	if (Skeleton->getColor().a == 0) return;
-
-	float depthOffset = 0;
-	unsigned short quadIndices[] = {0, 1, 2, 0, 2, 3};
-
-	for (size_t i = 0; i < Skeleton->getSlots().size(); ++i) {
-		Vector<float> *attachmentVertices = &worldVertices;
-		unsigned short *attachmentIndices = nullptr;
-		int numVertices;
-		int numIndices;
-		AtlasRegion *attachmentAtlasRegion = nullptr;
-		spine::Color attachmentColor;
-		attachmentColor.set(1, 1, 1, 1);
-		float *attachmentUvs = nullptr;
-
-		Slot *slot = Skeleton->getDrawOrder()[i];
-		Attachment *attachment = slot->getAttachment();
-
-		if (slot->getColor().a == 0 || !slot->getBone().isActive()) {
-			clipper.clipEnd(*slot);
-			continue;
-		}
-
-		if (!attachment) {
-			clipper.clipEnd(*slot);
-			continue;
-		}
-		if (!attachment->getRTTI().isExactly(RegionAttachment::rtti) && !attachment->getRTTI().isExactly(MeshAttachment::rtti) && !attachment->getRTTI().isExactly(ClippingAttachment::rtti)) {
-			clipper.clipEnd(*slot);
-			continue;
-		}
-
-		if (attachment->getRTTI().isExactly(RegionAttachment::rtti)) {
-			RegionAttachment *regionAttachment = (RegionAttachment *) attachment;
-
-			// Early out if region is invisible
-			if (regionAttachment->getColor().a == 0) {
-				clipper.clipEnd(*slot);
-				continue;
-			}
-
-			attachmentColor.set(regionAttachment->getColor());
-			attachmentAtlasRegion = (AtlasRegion *) regionAttachment->getRendererObject();
-			regionAttachment->computeWorldVertices(slot->getBone(), *attachmentVertices, 0, 2);
-			attachmentIndices = quadIndices;
-			attachmentUvs = regionAttachment->getUVs().buffer();
-			numVertices = 4;
-			numIndices = 6;
-		} else if (attachment->getRTTI().isExactly(MeshAttachment::rtti)) {
-			MeshAttachment *mesh = (MeshAttachment *) attachment;
-
-			// Early out if region is invisible
-			if (mesh->getColor().a == 0) {
-				clipper.clipEnd(*slot);
-				continue;
-			}
-
-			attachmentColor.set(mesh->getColor());
-			attachmentAtlasRegion = (AtlasRegion *) mesh->getRendererObject();
-			mesh->computeWorldVertices(*slot, 0, mesh->getWorldVerticesLength(), *attachmentVertices, 0, 2);
-			attachmentIndices = mesh->getTriangles().buffer();
-			attachmentUvs = mesh->getUVs().buffer();
-			numVertices = mesh->getWorldVerticesLength() >> 1;
-			numIndices = mesh->getTriangles().size();
-		} else /* clipping */ {
-			ClippingAttachment *clip = (ClippingAttachment *) attachment;
-			clipper.clipStart(*slot, clip);
-			continue;
-		}
-
-		// if the user switches the atlas data while not having switched
-		// to the correct skeleton data yet, we won't find any regions.
-		// ignore regions for which we can't find a material
-		UMaterialInstanceDynamic *material = nullptr;
-		switch (slot->getData().getBlendMode()) {
-			case BlendMode_Normal:
-				if (!pageToNormalBlendMaterial.Contains(attachmentAtlasRegion->page)) {
-					clipper.clipEnd(*slot);
-					continue;
-				}
-				material = pageToNormalBlendMaterial[attachmentAtlasRegion->page];
-				break;
-			case BlendMode_Additive:
-				if (!pageToAdditiveBlendMaterial.Contains(attachmentAtlasRegion->page)) {
-					clipper.clipEnd(*slot);
-					continue;
-				}
-				material = pageToAdditiveBlendMaterial[attachmentAtlasRegion->page];
-				break;
-			case BlendMode_Multiply:
-				if (!pageToMultiplyBlendMaterial.Contains(attachmentAtlasRegion->page)) {
-					clipper.clipEnd(*slot);
-					continue;
-				}
-				material = pageToMultiplyBlendMaterial[attachmentAtlasRegion->page];
-				break;
-			case BlendMode_Screen:
-				if (!pageToScreenBlendMaterial.Contains(attachmentAtlasRegion->page)) {
-					clipper.clipEnd(*slot);
-					continue;
-				}
-				material = pageToScreenBlendMaterial[attachmentAtlasRegion->page];
-				break;
-			default:
-				if (!pageToNormalBlendMaterial.Contains(attachmentAtlasRegion->page)) {
-					clipper.clipEnd(*slot);
-					continue;
-				}
-				material = pageToNormalBlendMaterial[attachmentAtlasRegion->page];
-		}
-
-		if (clipper.isClipping()) {
-			clipper.clipTriangles(attachmentVertices->buffer(), attachmentIndices, numIndices, attachmentUvs, 2);
-			attachmentVertices = &clipper.getClippedVertices();
-			numVertices = clipper.getClippedVertices().size() >> 1;
-			attachmentIndices = clipper.getClippedTriangles().buffer();
-			numIndices = clipper.getClippedTriangles().size();
-			attachmentUvs = clipper.getClippedUVs().buffer();
-			if (clipper.getClippedTriangles().size() == 0) {
-				clipper.clipEnd(*slot);
-				continue;
-			}
-		}
-
-		if (lastMaterial != material) {
-			Flush(meshSection, vertices, indices, normals, uvs, colors, darkColors, lastMaterial);
-			lastMaterial = material;
-			idx = 0;
-		}
-
-		SetMaterial(meshSection, material);
-
-		uint8 r = static_cast<uint8>(Skeleton->getColor().r * slot->getColor().r * attachmentColor.r * 255);
-		uint8 g = static_cast<uint8>(Skeleton->getColor().g * slot->getColor().g * attachmentColor.g * 255);
-		uint8 b = static_cast<uint8>(Skeleton->getColor().b * slot->getColor().b * attachmentColor.b * 255);
-		uint8 a = static_cast<uint8>(Skeleton->getColor().a * slot->getColor().a * attachmentColor.a * 255);
-
-		float dr = slot->hasDarkColor() ? slot->getDarkColor().r : 0.0f;
-		float dg = slot->hasDarkColor() ? slot->getDarkColor().g : 0.0f;
-		float db = slot->hasDarkColor() ? slot->getDarkColor().b : 0.0f;
-
-		float *verticesPtr = attachmentVertices->buffer();
-		for (int j = 0; j < numVertices << 1; j += 2) {
-			colors.Add(FColor(r, g, b, a));
-			darkColors.Add(FVector(dr, dg, db));
-			vertices.Add(FVector(verticesPtr[j], depthOffset, verticesPtr[j + 1]));
-			uvs.Add(FVector2D(attachmentUvs[j], attachmentUvs[j + 1]));
-		}
-
-		int firstIndex = indices.Num();
-		for (int j = 0; j < numIndices; j++) {
-			indices.Add(idx + attachmentIndices[j]);
-		}
-
-		FVector normal = FVector(0, -1, 0);
-		if (numVertices > 2 &&
-			FVector::CrossProduct(
-					vertices[indices[firstIndex + 2]] - vertices[indices[firstIndex]],
-					vertices[indices[firstIndex + 1]] - vertices[indices[firstIndex]])
-							.Y > 0.f) {
-			normal.Y = 1;
-		}
-		for (int j = 0; j < numVertices; j++) {
-			normals.Add(normal);
-		}
-
-		idx += numVertices;
-		depthOffset += this->DepthOffset;
-
-		clipper.clipEnd(*slot);
-	}
-
-	Flush(meshSection, vertices, indices, normals, uvs, colors, darkColors, lastMaterial);
-	clipper.clipEnd();
-}
-
-#undef LOCTEXT_NAMESPACE
+/******************************************************************************
+ * Spine Runtimes License Agreement
+ * Last updated January 1, 2020. Replaces all prior versions.
+ *
+ * Copyright (c) 2013-2020, Esoteric Software LLC
+ *
+ * Integration of the Spine Runtimes into software or otherwise creating
+ * derivative works of the Spine Runtimes is permitted under the terms and
+ * conditions of Section 2 of the Spine Editor License Agreement:
+ * http://esotericsoftware.com/spine-editor-license
+ *
+ * Otherwise, it is permitted to integrate the Spine Runtimes into software
+ * or otherwise create derivative works of the Spine Runtimes (collectively,
+ * "Products"), provided that each user of the Products must obtain their own
+ * Spine Editor license and redistribution of the Products in any form must
+ * include this license and copyright notice.
+ *
+ * THE SPINE RUNTIMES ARE PROVIDED BY ESOTERIC SOFTWARE LLC "AS IS" AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL ESOTERIC SOFTWARE LLC BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES,
+ * BUSINESS INTERRUPTION, OR LOSS OF USE, DATA, OR PROFITS) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THE SPINE RUNTIMES, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *****************************************************************************/
+
+#include "Engine.h"
+#include "SpinePluginPrivatePCH.h"
+#include "spine/spine.h"
+#include <stdlib.h>
+
+#define LOCTEXT_NAMESPACE "Spine"
+
+using namespace spine;
+
+USpineSkeletonRendererComponent::USpineSkeletonRendererComponent(const FObjectInitializer& ObjectInitializer)
+	: UProceduralMeshComponent(ObjectInitializer) {
+	PrimaryComponentTick.bCanEverTick = true;
+	bTickInEditor = true;
+	bAutoActivate = true;
+
+	static ConstructorHelpers::FObjectFinder<UMaterialInterface> NormalMaterialRef(TEXT("/SpinePlugin/SpineUnlitNormalMaterial"));
+	NormalBlendMaterial = NormalMaterialRef.Object;
+
+	static ConstructorHelpers::FObjectFinder<UMaterialInterface> AdditiveMaterialRef(TEXT("/SpinePlugin/SpineUnlitAdditiveMaterial"));
+	AdditiveBlendMaterial = AdditiveMaterialRef.Object;
+
+	static ConstructorHelpers::FObjectFinder<UMaterialInterface> MultiplyMaterialRef(TEXT("/SpinePlugin/SpineUnlitMultiplyMaterial"));
+	MultiplyBlendMaterial = MultiplyMaterialRef.Object;
+
+	static ConstructorHelpers::FObjectFinder<UMaterialInterface> ScreenMaterialRef(TEXT("/SpinePlugin/SpineUnlitScreenMaterial"));
+	ScreenBlendMaterial = ScreenMaterialRef.Object;
+
+	TextureParameterName = FName(TEXT("SpriteTexture"));
+
+	worldVertices.ensureCapacity(1024 * 2);
+}
+
+void USpineSkeletonRendererComponent::FinishDestroy() {
+	Super::FinishDestroy();
+}
+
+void USpineSkeletonRendererComponent::BeginPlay() {
+	Super::BeginPlay();
+}
+
+void USpineSkeletonRendererComponent::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) {
+	Super::TickComponent(DeltaTime, TickType, ThisTickFunction);
+
+	AActor* owner = GetOwner();
+	if (owner) {
+		UClass* skeletonClass = USpineSkeletonComponent::StaticClass();
+		USpineSkeletonComponent* skeleton = Cast<USpineSkeletonComponent>(owner->GetComponentByClass(skeletonClass));
+
+		UpdateRenderer(skeleton);
+	}
+}
+
+void USpineSkeletonRendererComponent::UpdateRenderer(USpineSkeletonComponent* skeleton) {
+	if (skeleton && !skeleton->IsBeingDestroyed() && skeleton->GetSkeleton() && skeleton->Atlas) {
+		skeleton->GetSkeleton()->getColor().set(Color.R, Color.G, Color.B, Color.A);
+
+		if (atlasNormalBlendMaterials.Num() != skeleton->Atlas->atlasPages.Num()) {
+			atlasNormalBlendMaterials.SetNum(0);
+			pageToNormalBlendMaterial.Empty();
+			atlasAdditiveBlendMaterials.SetNum(0);
+			pageToAdditiveBlendMaterial.Empty();
+			atlasMultiplyBlendMaterials.SetNum(0);
+			pageToMultiplyBlendMaterial.Empty();
+			atlasScreenBlendMaterials.SetNum(0);
+			pageToScreenBlendMaterial.Empty();
+
+			for (int i = 0; i < skeleton->Atlas->atlasPages.Num(); i++) {
+				AtlasPage* currPage = skeleton->Atlas->GetAtlas()->getPages()[i];
+
+				UMaterialInstanceDynamic* material = UMaterialInstanceDynamic::Create(NormalBlendMaterial, this);
+				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
+				atlasNormalBlendMaterials.Add(material);
+				pageToNormalBlendMaterial.Add(currPage, material);
+
+				material = UMaterialInstanceDynamic::Create(AdditiveBlendMaterial, this);
+				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
+				atlasAdditiveBlendMaterials.Add(material);
+				pageToAdditiveBlendMaterial.Add(currPage, material);
+
+				material = UMaterialInstanceDynamic::Create(MultiplyBlendMaterial, this);
+				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
+				atlasMultiplyBlendMaterials.Add(material);
+				pageToMultiplyBlendMaterial.Add(currPage, material);
+
+				material = UMaterialInstanceDynamic::Create(ScreenBlendMaterial, this);
+				material->SetTextureParameterValue(TextureParameterName, skeleton->Atlas->atlasPages[i]);
+				atlasScreenBlendMaterials.Add(material);
+				pageToScreenBlendMaterial.Add(currPage, material);
+			}
+		}
+		else {
+			pageToNormalBlendMaterial.Empty();
+			pageToAdditiveBlendMaterial.Empty();
+			pageToMultiplyBlendMaterial.Empty();
+			pageToScreenBlendMaterial.Empty();
+
+			for (int i = 0; i < skeleton->Atlas->atlasPages.Num(); i++) {
+				AtlasPage* currPage = skeleton->Atlas->GetAtlas()->getPages()[i];
+				UTexture2D* texture = skeleton->Atlas->atlasPages[i];
+
+				UpdateRendererMaterial(currPage, texture, atlasNormalBlendMaterials[i], NormalBlendMaterial, pageToNormalBlendMaterial);
+				UpdateRendererMaterial(currPage, texture, atlasAdditiveBlendMaterials[i], AdditiveBlendMaterial, pageToAdditiveBlendMaterial);
+				UpdateRendererMaterial(currPage, texture, atlasMultiplyBlendMaterials[i], MultiplyBlendMaterial, pageToMultiplyBlendMaterial);
+				UpdateRendererMaterial(currPage, texture, atlasScreenBlendMaterials[i], ScreenBlendMaterial, pageToScreenBlendMaterial);
+			}
+		}
+		UpdateMesh(skeleton->GetSkeleton());
+	}
+	else {
+		ClearAllMeshSections();
+	}
+}
+
+void USpineSkeletonRendererComponent::UpdateRendererMaterial(spine::AtlasPage* CurrentPage, UTexture2D* Texture,
+	UMaterialInstanceDynamic*& CurrentInstance, UMaterialInterface* ParentMaterial,
+	TMap<spine::AtlasPage*, UMaterialInstanceDynamic*>& PageToBlendMaterial) {
+
+	UTexture* oldTexture = nullptr;
+	if (!CurrentInstance || !CurrentInstance->GetTextureParameterValue(TextureParameterName, oldTexture) ||
+		oldTexture != Texture || CurrentInstance->Parent != ParentMaterial) {
+
+		UMaterialInstanceDynamic* material = UMaterialInstanceDynamic::Create(ParentMaterial, this);
+		material->SetTextureParameterValue(TextureParameterName, Texture);
+		CurrentInstance = material;
+	}
+	PageToBlendMaterial.Add(CurrentPage, CurrentInstance);
+}
+
+void USpineSkeletonRendererComponent::Flush(int& Idx, TArray<FVector>& Vertices, TArray<int32>& Indices, TArray<FVector>& Normals, TArray<FVector2D>& Uvs, TArray<FColor>& Colors, TArray<FVector>& Colors2, UMaterialInstanceDynamic* Material) {
+	if (Vertices.Num() == 0) return;
+	SetMaterial(Idx, Material);
+
+	bool bShouldCreateCollision = false;
+	if (bCreateCollision) {
+		UWorld* world = GetWorld();
+		if (world && world->IsGameWorld()) {
+			bShouldCreateCollision = true;
+		}
+	}
+
+	GetBodySetup()->bGenerateMirroredCollision = GetComponentScale().X < 0 || GetComponentScale().Y < 0 || GetComponentScale().Z < 0;
+	CreateMeshSection(Idx, Vertices, Indices, Normals, Uvs, Colors, TArray<FProcMeshTangent>(), bShouldCreateCollision);
+
+	Vertices.SetNum(0);
+	Indices.SetNum(0);
+	Normals.SetNum(0);
+	Uvs.SetNum(0);
+	Colors.SetNum(0);
+	Colors2.SetNum(0);
+	Idx++;
+}
+
+void USpineSkeletonRendererComponent::UpdateMesh(Skeleton* Skeleton) {
+	TArray<FVector> vertices;
+	TArray<int32> indices;
+	TArray<FVector> normals;
+	TArray<FVector2D> uvs;
+	TArray<FColor> colors;
+	TArray<FVector> darkColors;
+
+	int idx = 0;
+	int meshSection = 0;
+	UMaterialInstanceDynamic* lastMaterial = nullptr;
+
+	ClearAllMeshSections();
+
+	// Early out if skeleton is invisible
+	if (Skeleton->getColor().a == 0) return;
+
+	float depthOffset = 0;
+	unsigned short quadIndices[] = { 0, 1, 2, 0, 2, 3 };
+
+	for (size_t i = 0; i < Skeleton->getSlots().size(); ++i) {
+		Vector<float>* attachmentVertices = &worldVertices;
+		unsigned short* attachmentIndices = nullptr;
+		int numVertices;
+		int numIndices;
+		AtlasRegion* attachmentAtlasRegion = nullptr;
+		spine::Color attachmentColor;
+		attachmentColor.set(1, 1, 1, 1);
+		float* attachmentUvs = nullptr;
+
+		Slot* slot = Skeleton->getDrawOrder()[i];
+		Attachment* attachment = slot->getAttachment();
+
+		if (slot->getColor().a == 0 || !slot->getBone().isActive()) {
+			clipper.clipEnd(*slot);
+			continue;
+		}
+
+		if (!attachment) {
+			clipper.clipEnd(*slot);
+			continue;
+		}
+		if (!attachment->getRTTI().isExactly(RegionAttachment::rtti) && !attachment->getRTTI().isExactly(MeshAttachment::rtti) && !attachment->getRTTI().isExactly(ClippingAttachment::rtti)) {
+			clipper.clipEnd(*slot);
+			continue;
+		}
+
+		if (attachment->getRTTI().isExactly(RegionAttachment::rtti)) {
+			RegionAttachment* regionAttachment = (RegionAttachment*)attachment;
+
+			// Early out if region is invisible
+			if (regionAttachment->getColor().a == 0) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+
+			attachmentColor.set(regionAttachment->getColor());
+			attachmentAtlasRegion = (AtlasRegion*)regionAttachment->getRendererObject();
+			regionAttachment->computeWorldVertices(slot->getBone(), *attachmentVertices, 0, 2);
+			attachmentIndices = quadIndices;
+			attachmentUvs = regionAttachment->getUVs().buffer();
+			numVertices = 4;
+			numIndices = 6;
+		}
+		else if (attachment->getRTTI().isExactly(MeshAttachment::rtti)) {
+			MeshAttachment* mesh = (MeshAttachment*)attachment;
+
+			// Early out if region is invisible
+			if (mesh->getColor().a == 0) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+
+			attachmentColor.set(mesh->getColor());
+			attachmentAtlasRegion = (AtlasRegion*)mesh->getRendererObject();
+			mesh->computeWorldVertices(*slot, 0, mesh->getWorldVerticesLength(), *attachmentVertices, 0, 2);
+			attachmentIndices = mesh->getTriangles().buffer();
+			attachmentUvs = mesh->getUVs().buffer();
+			numVertices = mesh->getWorldVerticesLength() >> 1;
+			numIndices = mesh->getTriangles().size();
+		}
+		else /* clipping */ {
+			ClippingAttachment* clip = (ClippingAttachment*)attachment;
+			clipper.clipStart(*slot, clip);
+			continue;
+		}
+
+		// if the user switches the atlas data while not having switched
+		// to the correct skeleton data yet, we won't find any regions.
+		// ignore regions for which we can't find a material
+		UMaterialInstanceDynamic* material = nullptr;
+		switch (slot->getData().getBlendMode()) {
+		case BlendMode_Normal:
+			if (!pageToNormalBlendMaterial.Contains(attachmentAtlasRegion->page)) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+			material = pageToNormalBlendMaterial[attachmentAtlasRegion->page];
+			break;
+		case BlendMode_Additive:
+			if (!pageToAdditiveBlendMaterial.Contains(attachmentAtlasRegion->page)) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+			material = pageToAdditiveBlendMaterial[attachmentAtlasRegion->page];
+			break;
+		case BlendMode_Multiply:
+			if (!pageToMultiplyBlendMaterial.Contains(attachmentAtlasRegion->page)) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+			material = pageToMultiplyBlendMaterial[attachmentAtlasRegion->page];
+			break;
+		case BlendMode_Screen:
+			if (!pageToScreenBlendMaterial.Contains(attachmentAtlasRegion->page)) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+			material = pageToScreenBlendMaterial[attachmentAtlasRegion->page];
+			break;
+		default:
+			if (!pageToNormalBlendMaterial.Contains(attachmentAtlasRegion->page)) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+			material = pageToNormalBlendMaterial[attachmentAtlasRegion->page];
+		}
+
+		if (clipper.isClipping()) {
+			clipper.clipTriangles(attachmentVertices->buffer(), attachmentIndices, numIndices, attachmentUvs, 2);
+			attachmentVertices = &clipper.getClippedVertices();
+			numVertices = clipper.getClippedVertices().size() >> 1;
+			attachmentIndices = clipper.getClippedTriangles().buffer();
+			numIndices = clipper.getClippedTriangles().size();
+			attachmentUvs = clipper.getClippedUVs().buffer();
+			if (clipper.getClippedTriangles().size() == 0) {
+				clipper.clipEnd(*slot);
+				continue;
+			}
+		}
+
+		if (lastMaterial != material) {
+			Flush(meshSection, vertices, indices, normals, uvs, colors, darkColors, lastMaterial);
+			lastMaterial = material;
+			idx = 0;
+		}
+
+		SetMaterial(meshSection, material);
+
+		uint8 r = static_cast<uint8>(Skeleton->getColor().r * slot->getColor().r * attachmentColor.r * 255);
+		uint8 g = static_cast<uint8>(Skeleton->getColor().g * slot->getColor().g * attachmentColor.g * 255);
+		uint8 b = static_cast<uint8>(Skeleton->getColor().b * slot->getColor().b * attachmentColor.b * 255);
+		uint8 a = static_cast<uint8>(Skeleton->getColor().a * slot->getColor().a * attachmentColor.a * 255);
+
+		float dr = slot->hasDarkColor() ? slot->getDarkColor().r : 0.0f;
+		float dg = slot->hasDarkColor() ? slot->getDarkColor().g : 0.0f;
+		float db = slot->hasDarkColor() ? slot->getDarkColor().b : 0.0f;
+
+		float* verticesPtr = attachmentVertices->buffer();
+		for (int j = 0; j < numVertices << 1; j += 2) {
+			colors.Add(FColor(r, g, b, a));
+			darkColors.Add(FVector(dr, dg, db));
+			vertices.Add(FVector(verticesPtr[j], depthOffset, verticesPtr[j + 1]));
+			uvs.Add(FVector2D(attachmentUvs[j], attachmentUvs[j + 1]));
+		}
+
+		int firstIndex = indices.Num();
+		for (int j = 0; j < numIndices; j++) {
+			indices.Add(idx + attachmentIndices[j]);
+		}
+
+
+
+		//Calculate total triangle to add on this loof.
+
+		int TriangleInitialCount = firstIndex / 3;
+
+		int TriangleToAddNum = indices.Num() / 3 - TriangleInitialCount;
+
+		int FirstVertexIndex = vertices.Num() - numVertices;
+
+		//loof through all the triangles and resolve to be reversed if the triangle has winding order as CCW.
+
+		for (int j = 0; j < TriangleToAddNum; j++) {
+
+			const int TargetTringleIndex = firstIndex + j * 3;
+
+			if (FVector::CrossProduct(
+				vertices[indices[TargetTringleIndex + 2]] - vertices[indices[TargetTringleIndex]],
+				vertices[indices[TargetTringleIndex + 1]] - vertices[indices[TargetTringleIndex]]).Y < 0.f)
+			{
+
+				const int32 targetVertex = indices[TargetTringleIndex];
+				indices[TargetTringleIndex] = indices[TargetTringleIndex + 2];
+				indices[TargetTringleIndex + 2] = targetVertex;
+
+			}
+		}
+
+
+
+		FVector normal = FVector(0, 1, 0);
+
+		//Add normals for vertices.
+
+		for (int j = 0; j < numVertices; j++) {
+
+			normals.Add(normal);
+
+		}
+
+		idx += numVertices;
+		depthOffset += this->DepthOffset;
+
+		clipper.clipEnd(*slot);
+	}
+
+	Flush(meshSection, vertices, indices, normals, uvs, colors, darkColors, lastMaterial);
+	clipper.clipEnd();
+}
+
+#undef LOCTEXT_NAMESPACE