Add optional parameter to the ComputeCharacteristic method to pass a 'up direction' to compute signed roughness

Author: dgirardeau

include/GeometricalAnalysisTools.h

@@ -48,6 +48,7 @@ namespace CCCoreLib
 			\param subOption feature / curvature type / local density computation algorithm or nothing (0)
 			\param cloud cloud to compute the characteristic on
 			\param kernelRadius neighbouring sphere radius
+			\param roughnessUpDir up direction to compute signed roughness values (optional)
 			\param progressCb client application can get some notification of the process progress through this callback mechanism (see GenericProgressCallback)
 			\param inputOctree if not set as input, octree will be automatically computed.
 			\return succes
@@ -56,6 +57,7 @@ namespace CCCoreLib
 												int subOption,
 												GenericIndexedCloudPersist* cloud,
 												PointCoordinateType kernelRadius,
+												CCVector3* roughnessUpDir = nullptr,
 												GenericProgressCallback* progressCb = nullptr,
 												DgmOctree* inputOctree = nullptr);
 

include/Neighbourhood.h

@@ -194,11 +194,13 @@ namespace CCCoreLib
 		**/
 		ScalarType computeMomentOrder1(const CCVector3& P);
 
-		//! Computes the roughness of a set of point (by fitting a 2D plane)
-		/** \return roughness value at a given position P
+		//! Computes the roughness of a point (by fitting a 2D plane on its neighbors)
+		/** \param P point for which to compute the roughness value
+			\param roughnessUpDir up direction to compute a signed roughness value (optional)
+			\return roughness value at a given position P
 			\warning The point P shouldn't be in the set of points
 		**/
-		ScalarType computeRoughness(const CCVector3& P);
+		ScalarType computeRoughness(const CCVector3& P, CCVector3* roughnessUpDir = nullptr);
 
 		//! Computes the curvature of a set of point (by fitting a 2.5D quadric)
 		/** \return curvature value at a given position P or CCCoreLib::NAN_VALUE if the computation failed

src/GeometricalAnalysisTools.cpp

@@ -26,6 +26,7 @@ GeometricalAnalysisTools::ErrorCode GeometricalAnalysisTools::ComputeCharactersi
 		int subOption,
 		GenericIndexedCloudPersist* cloud,
 		PointCoordinateType kernelRadius,
+		CCVector3* roughnessUpDir/*=nullptr*/,
 		GenericProgressCallback* progressCb/*=nullptr*/,
 		DgmOctree* inputOctree/*=nullptr*/)
 {
@@ -104,7 +105,8 @@ GeometricalAnalysisTools::ErrorCode GeometricalAnalysisTools::ComputeCharactersi
 	{
 		static_cast<void*>(&c),
 		static_cast<void*>(&subOption),
-		static_cast<void*>(&kernelRadius)
+		static_cast<void*>(&kernelRadius),
+		static_cast<void*>(roughnessUpDir)
 	};
 
 	ErrorCode result = NoError;
@@ -165,12 +167,13 @@ GeometricalAnalysisTools::ErrorCode GeometricalAnalysisTools::ComputeCharactersi
 
 bool GeometricalAnalysisTools::ComputeGeomCharacteristicAtLevel(const DgmOctree::octreeCell& cell,
 																void** additionalParameters,
-																NormalizedProgress* nProgress/*=0*/)
+																NormalizedProgress* nProgress/*=nullptr*/)
 {
 	//parameters
 	GeomCharacteristic c       = *static_cast<GeomCharacteristic*>(additionalParameters[0]);
 	int subOption              = *static_cast<Neighbourhood::CurvatureType*>(additionalParameters[1]);
 	PointCoordinateType radius = *static_cast<PointCoordinateType*>(additionalParameters[2]);
+	CCVector3* roughnessUpDir  = static_cast<CCVector3*>(additionalParameters[3]);
 
 	//structure for nearest neighbors search
 	DgmOctree::NearestNeighboursSphericalSearchStruct nNSS;
@@ -257,7 +260,7 @@ bool GeometricalAnalysisTools::ComputeGeomCharacteristicAtLevel(const DgmOctree:
 
 					DgmOctreeReferenceCloud neighboursCloud(&nNSS.pointsInNeighbourhood, neighborCount - 1); //we don't take the query point into account!
 					Neighbourhood Z(&neighboursCloud);
-					value = Z.computeRoughness(nNSS.queryPoint);
+					value = Z.computeRoughness(nNSS.queryPoint, roughnessUpDir);
 
 					//swap the points back to their original position (DGM: not necessary in this case)
 					//if (localIndex+1 < neighborCount)

src/Neighbourhood.cpp

@@ -901,12 +901,24 @@ double Neighbourhood::computeFeature(GeomFeature feature)
 	return value;
 }
 
-ScalarType Neighbourhood::computeRoughness(const CCVector3& P)
+ScalarType Neighbourhood::computeRoughness(const CCVector3& P, CCVector3* roughnessUpDir/*=nullptr*/)
 {
 	const PointCoordinateType* lsPlane = getLSPlane();
 	if (lsPlane)
 	{
-		return std::abs(DistanceComputationTools::computePoint2PlaneDistance(&P, lsPlane));
+		ScalarType distToPlane = DistanceComputationTools::computePoint2PlaneDistance(&P, lsPlane);
+		if (roughnessUpDir)
+		{
+			if (CCVector3::vdot(lsPlane, roughnessUpDir->u) < 0)
+			{
+				distToPlane = -distToPlane;
+			}
+		}
+		else
+		{
+			distToPlane = std::abs(distToPlane);
+		}
+		return distToPlane;
 	}
 	else
 	{