# Synopsis

PDX_MSGT gdx_EvalExtSurfPnt(long option, T_GDX_EXT_SURF *gdx_ext_surf, double uval, double vval, MTH_3DPNT point)

# Purpose

Evaluate a point on a GDX extruded surface

# Description

At a given pair of parameters, evaluates a point on a GDX_EXT_SURF entity.

# Input

## option

(not used)

## gdx_ext_surf

The GDX extruded surface structure pointer

## uval

The surface U parameter value to evaluate

## vval

The surface V parameter value to evaluate

# Output

## point

The XYZ 3D evaluated point location

# Return

          Low level error return
          .fi