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UE5 C++在Cesium上给定一个坐标垂直地面射线正交的地形高度

news 来源：原创 2024/9/19 14:24:30

一.方法一：需要一个Actor里，向下垂直射线。自身高度-射线距离。

#include "CesiumGlobeAnchorComponent.h"
#include "CesiumOriginShiftComponent.h"
#include "GeoTransforms.h"
#include "CesiumGeoreference.h"

	UPROPERTY(BlueprintReadOnly, EditAnywhere, meta = (AllowPrivateAccess = "true"))UCesiumGlobeAnchorComponent* globeAnchor;//地球组件UPROPERTY(BlueprintReadOnly, EditAnywhere, meta = (AllowPrivateAccess = "true"))UCesiumOriginShiftComponent* originShift;//地球组件UWorld* world;FHitResult hitRes;ECollisionChannel colChannel;GeoTransforms* geoTrans;ACesiumGeoreference* Geo;

核心逻辑如下，Pitch为-90.，俯仰向下。射线从自身射到自身前方50000000cm,返回的FHitResult里面可以拿到距离。自身的高度-距离就是地面高度。

if (globeAnchor != nullptr) {if ((!isnan(Latitude)) && (!isnan(Longitude))){globeAnchor->MoveToLongitudeLatitudeHeight(FVector(Longitude, Latitude, Atitude));//FVector actorLoc = globeAnchor->GetLongitudeLatitudeHeight();FVector actorLoc = GetActorLocation();globeAnchor->SetEastSouthUpif (globeAnchor != nullptr) {if ((!isnan(Latitude)) && (!isnan(Longitude))){globeAnchor->MoveToLongitudeLatitudeHeight(FVector(Longitude, Latitude, Atitude));//FVector actorLoc = globeAnchor->GetLongitudeLatitudeHeight();FVector actorLoc = GetActorLocation();globeAnchor->SetEastSouthUpRotation(FRotator(-90, 0 - 90, 0).Quaternion());bool isSuccess = world->LineTraceSingleByChannel(hitRes, actorLoc, actorLoc + GetActorForwardVector() * 50000000, colChannel);// 绘制射线DrawDebugLine(GetWorld(), actorLoc, hitRes.GetActor() ? hitRes.Location : actorLoc + GetActorForwardVector() * 50000000, FColor::Red, false, 1.0f);//GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Green, actorLoc.ToString());//GEngine->AddOnScreenDebugMessage(-1,10.0f,FColor::Red, GetActorForwardVector().ToString());/*if (Geo->IsValidLowLevel()){*///float z = Geo->TransformLongitudeLatitudeHeightPositionToUnreal(hitRes.Location).Z;float z = Atitude-(hitRes.Distance/100);//GEngine->AddOnScreenDebugMessage(-1, 10.0f, FColor::Red, FString::Printf(TEXT("%f"), z));return z;/*	}*/}Rotation(FRotator(-90, 0 - 90, 0).Quaternion());bool isSuccess = world->LineTraceSingleByChannel(hitRes, actorLoc, actorLoc + GetActorForwardVector() * 50000000, colChannel);// 绘制射线DrawDebugLine(GetWorld(), actorLoc, hitRes.GetActor() ? hitRes.Location : actorLoc + GetActorForwardVector() * 50000000, FColor::Red, false, 1.0f);//GEngine->AddOnScreenDebugMessage(-1, 10.f, FColor::Green, actorLoc.ToString());//GEngine->AddOnScreenDebugMessage(-1,10.0f,FColor::Red, GetActorForwardVector().ToString());/*if (Geo->IsValidLowLevel()){*///float z = Geo->TransformLongitudeLatitudeHeightPositionToUnreal(hitRes.Location).Z;float z = Atitude-(hitRes.Distance/100);//GEngine->AddOnScreenDebugMessage(-1, 10.0f, FColor::Red, FString::Printf(TEXT("%f"), z));return z;/*	}*/}

方法二. 在某个目标，上空射线得到位置。UE位置坐标系再通过CesiumGereforce组件转化为经纬度坐标系代码如下：。UE5的TransformLongitudeLatitudeHeightPositionToUnreal的支持double，UE4蓝图只支持float的可能需要改一下Cesium源码，UE4从零开始制作数字孪生道路监测平台_ue4数字孪生-CSDN博客。

float AAltitudeChecker::GetAltitudeByLongitudeAndLatitude(const float& Longitude, const float& Latitude) {FVector actorLoc = GetActorLocation();//SetActorRotation(FRotator(-90, 0, 0));if (globeAnchor) {globeAnchor->MoveToLongitudeLatitudeHeight(FVector( Longitude, Latitude, 10000.f ));globeAnchor->SetEastSouthUpRotation(FRotator(-90, 0, 0).Quaternion());bool isSuccess = world->LineTraceSingleByChannel(hitRes, actorLoc, actorLoc + GetActorForwardVector() * 50000000, colChannel);if (isSuccess) {float floatRes = GetUEABsByLLA(hitRes.Location).Z;return floatRes;}}return -1;
}FVector AAltitudeChecker::GetUEABsByLLA(const FVector& lla) {if(Geo->IsValidLowLevel())	return Geo->TransformLongitudeLatitudeHeightPositionToUnreal(FVector(lla.X, lla.Y, lla.Z));return FVector();
}