Files
UnrealEngine/Engine/Plugins/Runtime/MeshModelingToolset/Source/ModelingComponents/Private/AssetUtils/MeshDescriptionUtil.cpp
2025-05-18 13:04:45 +08:00

119 lines
4.7 KiB
C++

// Copyright Epic Games, Inc. All Rights Reserved.
#include "AssetUtils/MeshDescriptionUtil.h"
#include "Components/StaticMeshComponent.h"
#include "Engine/StaticMesh.h"
#include "StaticMeshAttributes.h"
#include "StaticMeshOperations.h"
void UE::MeshDescription::InitializeAutoGeneratedAttributes(FMeshDescription& Mesh, const FMeshBuildSettings* BuildSettings)
{
check(BuildSettings);
bool bHasValidNormals = false;
bool bHasValidTangents = false;
FStaticMeshConstAttributes Attributes(Mesh);
TArrayView<const FVector3f> VertexInstanceNormals = Attributes.GetVertexInstanceNormals().GetRawArray();
TArrayView<const FVector3f> VertexInstanceTangents = Attributes.GetVertexInstanceTangents().GetRawArray();
for (const FVertexInstanceID VertexInstanceID : Mesh.VertexInstances().GetElementIDs())
{
bHasValidNormals |= (!VertexInstanceNormals[VertexInstanceID].IsNearlyZero() && !VertexInstanceNormals[VertexInstanceID].ContainsNaN());
bHasValidTangents |= (!VertexInstanceTangents[VertexInstanceID].IsNearlyZero() && !VertexInstanceTangents[VertexInstanceID].ContainsNaN());
if (bHasValidNormals && bHasValidTangents)
{
break;
}
}
// rebuild normals/tangents if there are any invalid ones or the build settings request it
if (!bHasValidNormals || !bHasValidTangents || BuildSettings->bRecomputeNormals || BuildSettings->bRecomputeTangents)
{
bool bRecomputeNormals = !bHasValidNormals || BuildSettings->bRecomputeNormals;
bool bRecomputeTangents = !bHasValidTangents || BuildSettings->bRecomputeTangents;
if (!Attributes.GetTriangleNormals().IsValid() || !Attributes.GetTriangleTangents().IsValid())
{
// If these attributes don't exist, create them and compute their values for each triangle
FStaticMeshOperations::ComputeTriangleTangentsAndNormals(Mesh);
}
EComputeNTBsFlags ComputeNTBsOptions = EComputeNTBsFlags::BlendOverlappingNormals;
ComputeNTBsOptions |= bRecomputeNormals ? EComputeNTBsFlags::Normals : EComputeNTBsFlags::None;
ComputeNTBsOptions |= bRecomputeTangents ? EComputeNTBsFlags::Tangents : EComputeNTBsFlags::None;
ComputeNTBsOptions |= BuildSettings->bUseMikkTSpace ? EComputeNTBsFlags::UseMikkTSpace : EComputeNTBsFlags::None;
ComputeNTBsOptions |= BuildSettings->bComputeWeightedNormals ? EComputeNTBsFlags::WeightedNTBs : EComputeNTBsFlags::None;
ComputeNTBsOptions |= BuildSettings->bRemoveDegenerates ? EComputeNTBsFlags::IgnoreDegenerateTriangles : EComputeNTBsFlags::None;
FStaticMeshOperations::ComputeTangentsAndNormals(Mesh, ComputeNTBsOptions);
}
}
void UE::MeshDescription::InitializeAutoGeneratedAttributes(FMeshDescription& Mesh, UStaticMesh* StaticMesh, int32 SourceLOD)
{
#if WITH_EDITOR
if (ensureMsgf(SourceLOD < StaticMesh->GetNumSourceModels(), TEXT("InitializeMeshDescription requested LOD index greater than num available in UStaticMesh")))
{
const FStaticMeshSourceModel& SourceModel = StaticMesh->GetSourceModel(SourceLOD);
InitializeAutoGeneratedAttributes(Mesh, &SourceModel.BuildSettings);
}
#else
ensureMsgf(false, TEXT("InitializeMeshDescription requires Editor-only SourceModel field of UStaticMesh"));
#endif
}
void UE::MeshDescription::InitializeAutoGeneratedAttributes(FMeshDescription& Mesh, UActorComponent* StaticMeshComponent, int32 SourceLOD)
{
#if WITH_EDITOR
if (Cast<UStaticMeshComponent>(StaticMeshComponent) != nullptr)
{
UStaticMesh* StaticMesh = Cast<UStaticMeshComponent>(StaticMeshComponent)->GetStaticMesh();
if (ensure(StaticMesh != nullptr))
{
InitializeAutoGeneratedAttributes(Mesh, StaticMesh, SourceLOD);
}
}
#else
//ensureMsgf(false, TEXT("InitializeMeshDescription requires Editor-only SourceModel field of UStaticMesh"));
#endif
}
void UE::MeshDescription::ConfigureBuildSettings(UStaticMesh* StaticMesh, int32 SourceLOD, FStaticMeshBuildSettingChange NewSettings)
{
#if WITH_EDITOR
if (ensureMsgf(SourceLOD < StaticMesh->GetNumSourceModels(), TEXT("ConfigureBuildSettings requested LOD index greater than num available in UStaticMesh")))
{
FStaticMeshSourceModel& SourceModel = StaticMesh->GetSourceModel(SourceLOD);
if (NewSettings.AutoGeneratedNormals != EBuildSettingBoolChange::NoChange)
{
SourceModel.BuildSettings.bRecomputeNormals =
(NewSettings.AutoGeneratedNormals == EBuildSettingBoolChange::Disable) ? false : true;
}
if (NewSettings.AutoGeneratedTangents != EBuildSettingBoolChange::NoChange)
{
SourceModel.BuildSettings.bRecomputeTangents =
(NewSettings.AutoGeneratedTangents == EBuildSettingBoolChange::Disable) ? false : true;
}
if (NewSettings.UseMikkTSpaceTangents != EBuildSettingBoolChange::NoChange)
{
SourceModel.BuildSettings.bUseMikkTSpace =
(NewSettings.UseMikkTSpaceTangents == EBuildSettingBoolChange::Disable) ? false : true;
}
}
#else
// just ignore?
#endif
}