136 lines
4.0 KiB
Markdown
136 lines
4.0 KiB
Markdown
---
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title: Mass扩展笔记
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date: 2024-09-12 15:32:15
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excerpt:
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tags:
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rating: ⭐
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---
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#
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1. 创建 UMassEntityTraitBase （UMassVisualizationTrait）
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2. 相关的渲染设置逻辑位于UMassVisualizationComponent。
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# UMassVisualizationComponent
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```c++
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void UMassVisualizationComponent::ConstructStaticMeshComponents()
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{
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AActor* ActorOwner = GetOwner();
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check(ActorOwner);
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UE_MT_SCOPED_WRITE_ACCESS(InstancedStaticMeshInfosDetector);
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for (FMassInstancedStaticMeshInfo& Info : InstancedStaticMeshInfos)
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{
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// Check if it is already created
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if (!Info.InstancedStaticMeshComponents.IsEmpty())
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{
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continue;
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}
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// Check if there are any specified meshes for this visual type
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if(Info.Desc.Meshes.Num() == 0)
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{
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UE_LOG(LogMassRepresentation, Error, TEXT("No associated meshes for this intanced static mesh type"));
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continue;
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}
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for (const FStaticMeshInstanceVisualizationMeshDesc& MeshDesc : Info.Desc.Meshes)
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{
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FISMCSharedData* SharedData = ISMCSharedData.Find(MeshDesc);
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UInstancedStaticMeshComponent* ISMC = SharedData ? SharedData->ISMC : nullptr;
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if (SharedData)
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{
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SharedData->RefCount += 1;
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}
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else
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{
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ISMC = NewObject<UInstancedStaticMeshComponent>(ActorOwner);
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ISMC->SetStaticMesh(MeshDesc.Mesh);
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for (int32 ElementIndex = 0; ElementIndex < MeshDesc.MaterialOverrides.Num(); ++ElementIndex)
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{
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if (UMaterialInterface* MaterialOverride = MeshDesc.MaterialOverrides[ElementIndex])
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{
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ISMC->SetMaterial(ElementIndex, MaterialOverride);
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}
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}
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ISMC->SetCullDistances(0, 1000000); // @todo: Need to figure out what to do here, either LOD or cull distances.
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ISMC->SetupAttachment(ActorOwner->GetRootComponent());
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ISMC->SetCanEverAffectNavigation(false);
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ISMC->SetCollisionProfileName(UCollisionProfile::NoCollision_ProfileName);
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ISMC->SetCastShadow(MeshDesc.bCastShadows);
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ISMC->Mobility = MeshDesc.Mobility;
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ISMC->SetReceivesDecals(false);
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ISMC->RegisterComponent();
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ISMCSharedData.Emplace(MeshDesc, FISMCSharedData(ISMC));
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}
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Info.InstancedStaticMeshComponents.Add(ISMC);
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}
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// Build the LOD significance ranges
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TArray<float> AllLODSignificances;
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auto UniqueInsertOrdered = [&AllLODSignificances](const float Significance)
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{
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int i = 0;
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for (; i < AllLODSignificances.Num(); ++i)
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{
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// I did not use epsilon check here on purpose, because it will make it hard later meshes inside.
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if (Significance == AllLODSignificances[i])
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{
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return;
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}
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if (AllLODSignificances[i] > Significance)
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{
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break;
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}
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}
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AllLODSignificances.Insert(Significance, i);
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};
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for (const FStaticMeshInstanceVisualizationMeshDesc& MeshDesc : Info.Desc.Meshes)
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{
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UniqueInsertOrdered(MeshDesc.MinLODSignificance);
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UniqueInsertOrdered(MeshDesc.MaxLODSignificance);
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}
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Info.LODSignificanceRanges.SetNum(AllLODSignificances.Num() - 1);
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for (int i = 0; i < Info.LODSignificanceRanges.Num(); ++i)
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{
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FMassLODSignificanceRange& Range = Info.LODSignificanceRanges[i];
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Range.MinSignificance = AllLODSignificances[i];
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Range.MaxSignificance = AllLODSignificances[i+1];
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Range.ISMCSharedDataPtr = &ISMCSharedData;
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for (int j = 0; j < Info.Desc.Meshes.Num(); ++j)
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{
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const FStaticMeshInstanceVisualizationMeshDesc& MeshDesc = Info.Desc.Meshes[j];
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const bool bAddMeshInRange = (Range.MinSignificance >= MeshDesc.MinLODSignificance && Range.MinSignificance < MeshDesc.MaxLODSignificance);
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if (bAddMeshInRange)
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{
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Range.StaticMeshRefs.Add(MeshDesc);
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}
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}
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}
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}
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}
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```
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设置灯光通道：
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```c++
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void UPrimitiveComponent::SetLightingChannels(bool bChannel0, bool bChannel1, bool bChannel2)
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{
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if (bChannel0 != LightingChannels.bChannel0 ||
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bChannel1 != LightingChannels.bChannel1 ||
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bChannel2 != LightingChannels.bChannel2)
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{
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LightingChannels.bChannel0 = bChannel0;
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LightingChannels.bChannel1 = bChannel1;
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LightingChannels.bChannel2 = bChannel2;
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if (SceneProxy)
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{
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SceneProxy->SetLightingChannels_GameThread(LightingChannels);
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}
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MarkRenderStateDirty();
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}
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}
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``` |