UE4 FindCollisionUV

FindCollisionUV可以做碰撞或击中某物件上碰撞点对应的UV坐标，我们可以基于该UV坐标作为材质参数传入到该物件材质中做一些碰撞或击中材质效果。注意：碰撞或射线检测，必须开启复杂检测，该物件设置开启物理。

/** 
	 *	Try and find the UV for a collision impact. Note this ONLY works if 'Support UV From Hit Results' is enabled in Physics Settings.
	 */
	UFUNCTION(BlueprintPure, Category = "Collision")
	static bool FindCollisionUV(const struct FHitResult& Hit, int32 UVChannel, FVector2D& UV);


bool UGameplayStatics::FindCollisionUV(const struct FHitResult& Hit, int32 UVChannel, FVector2D& UV)
{
	bool bSuccess = false;

	if (!UPhysicsSettings::Get()->bSupportUVFromHitResults)
	{
		FMessageLog("PIE").Warning(LOCTEXT("CollisionUVNoSupport", "Calling FindCollisionUV but 'Support UV From Hit Results' is not enabled in project settings. This is required for finding UV for collision results."));
	}
	else
	{
		UPrimitiveComponent* HitPrimComp = Hit.Component.Get();
		if (HitPrimComp)
		{
			UBodySetup* BodySetup = HitPrimComp->GetBodySetup();
			if (BodySetup)
			{
				const FVector LocalHitPos = HitPrimComp->GetComponentToWorld().InverseTransformPosition(Hit.Location);

				bSuccess = BodySetup->CalcUVAtLocation(LocalHitPos, Hit.FaceIndex, UVChannel, UV);
			}
		}
	}

	return bSuccess;
}

基于官方第一人称例子工程，使用如下图：