LidarScannerLibrary.h

// Copyright Mars Rover 2025
 
#pragma once
 
#include "Async/ParallelFor.h"
#include "CoreMinimal.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "Engine/World.h"
#include "LidarScannerLibrary.generated.h"
 
 
class AGeoReferencingSystem;
 
USTRUCT(BlueprintType)
struct FLidarPoint
{
  GENERATED_BODY()
 
  UPROPERTY(BlueprintReadOnly, Category = "Lidar Point")
  double Easting;
 
  UPROPERTY(BlueprintReadOnly, Category = "Lidar Point")
  double Northing;
 
  UPROPERTY(BlueprintReadOnly, Category = "Lidar Point")
  double Altitude;
 
  UPROPERTY(BlueprintReadOnly, Category = "Lidar Point")
  uint8 Classification;
};
 
/**
 * @brief Blueprintable library to simulate Lidar Scanning for Autonomy
 */
UCLASS()
class ROVESOSIMULATOR_API ULidarScannerLibrary : public UBlueprintFunctionLibrary
{
  GENERATED_BODY()
 
public:
  /**
   * Performs a grid-based ray trace over a specified area to generate a point cloud.
   * @param WorldContextObject The world context.
   * @param ScanBoundsMin The minimum corner of the 2D scan area (X, Y).
   * @param ScanBoundsMax The maximum corner of the 2D scan area (X, Y).
   * @param TraceZ_Start The Z-height to start traces from.
   * @param TraceZ_End The Z-height to end traces at.
   * @param Density The desired number of points per square meter.
   * @return An array of FVectors representing the hit locations.
   */
  UFUNCTION(BlueprintCallable, Category = "Lidar Tools")
  static TArray<FVector> ScanForLidarPoints(
  //static TArray<FLidarPoint> ScanAndGeoreferencePoints(
    UObject* WorldContextObject,
    FVector2D ScanBoundsMin,
    FVector2D ScanBoundsMax,
    float TraceZ_Start,
    float TraceZ_End,
    float Density
  );
 
  /**
   * Performs a grid-based ray trace over a specified area to generate a georeferenced point cloud.
   * @param WorldContextObject The world context.
   * @param ScanBoundsMin The minimum corner of the 2D scan area (X, Y).
   * @param ScanBoundsMax The maximum corner of the 2D scan area (X, Y).
   * @param TraceZ_Start The Z-height to start traces from.
   * @param TraceZ_End The Z-height to end traces at.
   * @param Density The desired number of points per square meter.
   * @return An array of FLidarPoint structs containing georeferenced coordinates and classification.
   */
  UFUNCTION(BlueprintCallable, Category = "Lidar Tools")
  static TArray<FLidarPoint> ScanAndGeoreferencePoints(
    UObject* WorldContextObject,
    FVector2D ScanBoundsMin,
    FVector2D ScanBoundsMax,
    float TraceZ_Start,
    float TraceZ_End,
    float Density
  );
 
  /**
   * Exports an array of LidarPoint data to a simple CSV text file.
   * @param LidarPoints The array of points to export.
   * @param FilePath The full path where the file will be saved (e.g., "C:/LidarScans/MyScan.csv").
   * @return True if the file was written successfully, false otherwise.
   */
  UFUNCTION(BlueprintCallable, Category = "Lidar Tools")
  static bool ExportLidarDataToCSV(const TArray<FLidarPoint>& LidarPoints, const FString& FilePath);
 
  /**
   * Scans a large area in manageable chunks and exports each chunk's data to separate CSV files.
   * @param WorldContextObject The world context.
   * @param ScanBoundsMin The minimum corner of the overall 2D scan area (X, Y).
   * @param ScanBoundsMax The maximum corner of the overall 2D scan area (X, Y).
   * @param TraceZ_Start The Z-height to start traces from.
   * @param TraceZ_End The Z-height to end traces at.
   * @param Density The desired number of points per square meter.
   * @param ChunkSizeMeters The size of each chunk in meters (e.g., 200 for 200x200m chunks).
   * @param OutputDirectory The directory where all chunk files will be saved.
   */
  UFUNCTION(BlueprintCallable, Category = "Lidar Tools")
  static void ScanWorldInChunks(
    UObject* WorldContextObject,
    FVector2D ScanBoundsMin,
    FVector2D ScanBoundsMax,
    float TraceZ_Start,
    float TraceZ_End,
    float Density,
    float ChunkSizeMeters, // User-defined size for each chunk (e.g., 200 meters)
    const FString& OutputDirectory // The FOLDER where all chunk files will be saved
  );
 
private:
  // This is our "Worker" function. It's not exposed to Blueprints,
  // as it's only called by our manager function.
  static bool ScanAndExportChunkToCSV(
    const UWorld* World,
    /*class AGeoReferencingSystem* GeoSystem,*/
    const AGeoReferencingSystem* GeoSystem,
    FVector2D ChunkBoundsMin,
    FVector2D ChunkBoundsMax,
    float TraceZ_Start,
    float TraceZ_End,
    float Density,
    const FString& FilePath // The full path for this specific chunk's output file
  );
 
};