/**
默认 TraceTypeQuery1 —— Visibility
默认 TraceTypeQuery2 —— Camera
*/
void ATraceCharacter::traceByChannel() {//获取该组件的拥有者AActor* MyOwner = GetOwner();//射线的开始位置和结束位置FVector Start;FRotator StartRotation;MyOwner->GetActorEyesViewPoint(Start, StartRotation);//Start = Mesh1P->GetComponentLocation();FVector End = Start + StartRotation.Vector() * 1000.0f;FHitResult Hit;//根据通道查询 在这里需要注意AddIgnoredActor添加了该射线忽略的Actor，不然会造成检测错误FCollisionQueryParams QueryParams;QueryParams.AddIgnoredActor(MyOwner);/** * 参数类型*Hit碰撞信息 起始点、结束点、碰撞通道、查询参数*/bool BIsTraced = GetWorld()->LineTraceSingleByChannel(Hit, Start, End, ECollisionChannel::ECC_Visibility, QueryParams);if (BIsTraced) {UKismetSystemLibrary::PrintString(GetWorld(), FString::Printf(TEXT("LineTraceSingleByChannel : %s"), *Hit.Actor->GetName()));}
}/**
默认 ObjectTypeQuery1 —— WorldStatic
默认 ObjectTypeQuery2 —— WorldDynamic
默认 ObjectTypeQuery3 —— Oawn
默认 ObjectTypeQuery4 —— PhysicasBody
默认 ObjectTypeQuery5 —— Vehicle
默认 ObjectTypeQuery6 —— Destructible
*/
void ATraceCharacter::traceByObjType() {//获取该组件的拥有者AActor* MyOwner = GetOwner();//射线的开始位置和结束位置FVector Start;FRotator StartRotation;MyOwner->GetActorEyesViewPoint(Start, StartRotation);FVector End = Start + StartRotation.Vector() * 4000;//碰撞对象查询FCollisionObjectQueryParams ObjectQueryParams;ObjectQueryParams.AddObjectTypesToQuery(ECollisionChannel::ECC_WorldStatic);//单通道射线根据对象类型检测FHitResult Hit;/*** 参数类型* Hit碰撞信息、起始点、结束点、对象检测参数。*/bool BIsTraced = GetWorld()->LineTraceSingleByObjectType(Hit, Start, End, ObjectQueryParams);if (BIsTraced) {UKismetSystemLibrary::PrintString(GetWorld(), FString::Printf(TEXT("LineTraceSingleByObjectType : %s"), *Hit.Actor->GetName()));}
}

以下是不常用

void ATraceCharacter::traceHit() {AMainPlayerController* PC = Cast(UGameplayStatics::GetPlayerController(GetWorld(), 0));//获取屏幕宽高int32 width = 0;int32 height = 0;PC->GetViewportSize(width, height);//将屏幕位置投影到世界FVector STMPos;FVector STMDir;//宽高/2就是屏幕中心点PC->DeprojectScreenPositionToWorld(width / 2, height / 2, STMPos, STMDir);FVector CameraPos = PC->PlayerCameraManager->GetCameraLocation();FVector CameraDir = PC->PlayerCameraManager->GetActorForwardVector() * 300;FHitResult Hit;//摄像机发射射线，单射线检查，只有一个目标//Start:CameraPos + CameraDir//End: CameraPos + STMDir * 5000 ,相机位置往世界方向发射一条5000长的射线if (GetWorld()->LineTraceSingleByChannel(Hit, CameraPos + CameraDir, CameraPos + STMDir * 5000, ECC_Camera)) {FString msg = Hit.GetActor()->GetName();GEngine->AddOnScreenDebugMessage(-1, 2.0, FColor::Red, msg + TEXT(" hitting..."));UTraceInterface* trace = Cast(Hit.Actor);if (trace) {UE_LOG(LogTemp, Warning, TEXT("**************"));}}
}void ATraceCharacter::traceFire() {AMainPlayerController* PC = Cast(UGameplayStatics::GetPlayerController(GetWorld(), 0));FVector FireStart, FireEnd;FireStart = FirstPersonCameraComponent->GetComponentLocation() + FirstPersonCameraComponent->GetForwardVector();FireEnd = FirstPersonCameraComponent->GetForwardVector() * 1500 + FireStart;FHitResult OutHit;TArray ActorsToIgnotre;UKismetSystemLibrary::LineTraceSingle(this, FireStart, FireEnd, ETraceTypeQuery::TraceTypeQuery1, false, ActorsToIgnotre, EDrawDebugTrace::ForDuration, OutHit, true);UTraceInterface* trace = Cast(OutHit.Actor);if (trace) {FString msg = OutHit.GetActor()->GetName();GEngine->AddOnScreenDebugMessage(-1, 2.0, FColor::Red, msg + TEXT(" hitting..."));}
}void ATraceCharacter::traceFire2() {FRotator cameraRotator = FirstPersonCameraComponent->GetComponentRotation();//相机向前的方向FVector cameraForward = UKismetMathLibrary::GetForwardVector(cameraRotator);UE_LOG(LogTemp, Warning, TEXT("cameraForward: (X:%f,Y:%f,Z:%f)"), cameraForward.X, cameraForward.Y, cameraForward.Z);//相机的位置 向量的取值范围在 -1 ~ 1之间FVector cameraLocation = FirstPersonCameraComponent->GetComponentLocation();UE_LOG(LogTemp, Warning, TEXT("cameraLocation: (X:%f,Y:%f,Z:%f)"), cameraLocation.X, cameraLocation.Y, cameraLocation.Z);//射线结束位置FVector endLocation = cameraLocation + cameraForward * 1500;UE_LOG(LogTemp, Warning, TEXT("endLocation: (X:%f,Y:%f,Z:%f)"), endLocation.X, endLocation.Y, endLocation.Z);FHitResult hitResult;TArrayignoreArray;bool bHit = UKismetSystemLibrary::LineTraceSingle(GetWorld(), cameraLocation, endLocation, ETraceTypeQuery::TraceTypeQuery1, false, ignoreArray, EDrawDebugTrace::Persistent, hitResult, true/*, FLinearColor::Red, FLinearColor::Green, 2.0*/);if (bHit){UKismetSystemLibrary::PrintString(GetWorld(),FString::Printf(TEXT("Name:%s"), *hitResult.Actor->GetName()));}
}void ATraceCharacter::traceByChannelDraw() {// 碰撞参数FCollisionQueryParams CollisonQueryParams(TEXT("QueryParams"), true, NULL);CollisonQueryParams.bTraceComplex = true;CollisonQueryParams.bReturnPhysicalMaterial = false;CollisonQueryParams.AddIgnoredActor(this);// 起始点和检测结果FVector BeginLoc = GetActorLocation();FVector EndLoc = BeginLoc + GetActorForwardVector() * 4000;FHitResult HitResult;// 射线检测GetWorld()->LineTraceSingleByChannel(HitResult, BeginLoc, EndLoc, ECollisionChannel::ECC_Visibility, CollisonQueryParams);// 绘制射线//DrawDebugLine(GetWorld(), BeginLoc, HitResult.GetActor() ? HitResult.Location : EndLoc, FColor::Red, false, 1.0f);if (HitResult.GetActor()) {UKismetSystemLibrary::PrintString(GetWorld(), HitResult.GetActor()->GetName());}
}

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