API Reference > geometry-core > CartesianGeometry > Plane3dByOriginAndUnitNormal > velocityXYZ velocityXYZ Method Return the dot product of spaceVector with the plane's unit normal. This tells the rate of change of altitude for a point moving at speed one along the spaceVector. velocityXYZ(x: number, y: number, z: number): number Parameter Type Description x number y number z number Returns - number Defined in geometry3d/Plane3dByOriginAndUnitNormal.ts Line 229 Last Updated: 12 June, 2024