OdDbRay::getFirstDeriv Method

Syntax

C++

virtual OdResult getFirstDeriv(double param, OdGeVector3d& firstDeriv) const;

Parameters	Description
double param	[in] Parameter value specifying the point on the ray as a Double value.
OdGeVector3d& firstDeriv	[out] Reference to a variable in which this method must save the first derivative as three-dimensional vector instance.

Description

Computes the first derivative for the specified parameter of the ray entity and returns the three-dimensional vector instance. The first derivative is constant for any point of the ray.