UE4 VR中血条的做法 3d widget

本文地址：https://www.cnblogs.com/LynnVon/p/14113249.html

项目需要要在VR中标记物体的位置及距离等，正常情况我们做血条之类的我们可以用Widget然后Space为screen就可以，VR里就不可以了。

VR里我们将widget的space切换为world，然后还需要widget的scale跟随其与camera的距离变化（maprange）

float scale = UKismetMathLibrary::MapRangeClamped(Dis, MAXDis, MINDis, Out1, Out2);
	this->SetWorldScale3D(FVector(scale, scale, scale));

然后我们使widget始终面向camera

void UDistanceMsgComponent::LookAtPlayer()
{
    FRotator WidgetComponentRotator = GetComponentRotation();
    FRotator CameraRotator = UGameplayStatics::GetPlayerCameraManager(this, 0)->GetCameraRotation();

    this->SetWorldRotation(FRotator(-CameraRotator.Pitch, CameraRotator.Yaw + 180, WidgetComponentRotator.Roll));
}

再然后，我们需要使widget始终处于其他物体的前方，也就是渲染在最上方，否则会被其他物体挡住，可以参考https://answers.unrealengine.com/questions/207400/3d-widget-ztest-off.html

其中一下方法我觉得是最好的一个

Another option is copying the Material Widget3DPassThrough.asset from the Engine Content to your Project Content (rename it to something else like Widget3DPassThrough_2.asset), then edit the Material Widget3DPassThrough_Translucent.asset (your 3d widget material) changing its parent to Widget3DPassThrough_2.asset and disable the ZTest on Widget3DPassThrough_2.asset.