Synopsis

PDX_MSGT gdx_EvalSurfaceNormal(long option, MDA_PTR db_ptr, double uval, double vval, double normal[3])

Purpose

Evaluate a normal on a GDX surface entity

Description

At U and V parameter values, evaluate a normal on the GDX surface entity.

Input

option

GDX_UNNORM

Unnormalize the parameter values

GDX_FROMLEFT

Evaluate the point location from the left

GDX_FROMLOW

Evaluate the point location from the low parameter direction

db_ptr

The GDX surface entity database pointer

uval

The U parameter value to evaluate

vval

The V parameter value to evaluate

Output

normal

The XYZ 3D evaluated normal direction vector (normalized)

Return

      GDX_DEGEN_PARM
      GDX_NOERR
      Low level error return
      .fi