# Synopsis

PDX_MSGT gdx_FaceExtractSurface(long option, double u0, double u1, double v0, double v1, double devtol, PDX_BOOL *parm_change, MDA_PTR gdx_face_ptr)

# Purpose

Extract the surface in a face.

# Description

Extract a surface in a face. The surface will be replaced in the face. The original surface will be deleted is this face is the only parent. If a parm change occurs, then the parm curves will be deleted

# Input

## option

Options (Not Used)

## u0

The u-directional extraction start parameter.

## u1

The u-directional extraction end parameter. If u0 > u1, then the surface must be closed in the u-direction, and the resulting subsurface will include the u-seam (and portions of the surface to either side of the u-seam).

## v0

The v-directional extraction start parameter.

## v1

The v-directional extraction end parameter. If u0 > v1, then the surface must be closed in the v-direction, and the resulting subsurface will include the v-seam (and portions of the surface to either side of the v-seam).

## devtol

Tolerance used during extraction of surface

## gdx_face_ptr

DB pointer of face with surface to be extracted

# Output

## parm_change

Flag indicating the parameterization of the new surface is different than the old surface. Parm curves will be deleted from the face.

## gdx_face_ptr

Face with extracted surface

# Tolerances

          MODEL_SPACE_PNT_TOL
          PARM_SPACE_PNT_TOL
          ANGLE_TOL
          ZERO_TOL
          .fi

# Return

          GDX_NOERR
          GDX_INVALIDMODEL
          Low level error return
          .fi