GradeAlong

Rise over run of the ground along a horizontal direction, a central difference one edit cell either side of the point.

Declaration

double GradeAlong(const FGroundQuery& Query, double X, double Y, double DirX, double DirY,
                                          ESurface Surface, EPrecision& OutPrecision);

Header: #include "Native/GroundSampling.h"
Module: PublicDependencyModuleNames.Add("OrreryTerrainCore"); in your module’s Build.cs.
Stability: Stable: changes within a major version only add.
Thread: Any thread, lock-free.

Parameters

Name	Type	Default	Meaning
`Query`	`const FGroundQuery&`	—	The snapshot to read.
`X`	`double`	—	Position, world metres.
`Y`	`double`	—	Position, world metres.
`DirX`	`double`	—	Horizontal direction; need not be unit, only its XY direction counts.
`DirY`	`double`	—	Horizontal direction; need not be unit, only its XY direction counts.
`Surface`	`ESurface`	—	Which ground.
`OutPrecision`	`EPrecision&`	—	Worst precision of the heights read; NoData (and a result of 0) when the point has no ground or the direction is zero.

Returns

dZ/ds, positive uphill along the direction (0.1 = 10 %).

Note.

Any thread, lock-free.