# Synopsis

PDX_MSGT gdx_SurfaceGetRevolveAxis(long option, MDA_PTR gdx_surf_ptr, PDX_BOOL *rev_flag, PDX_BOOL *v_revolve, MTH_3DPNT center, MTH_3DVEC vec)

# Purpose

Find the revolve axis of a surface

# Description

The revolve axis of a GDX surface will be found if the surface is a revolve one. The surface can be any GDX surface.

If not a revolve surface, the function returns GDX_NOERR and rev_flag = PDX_FALSE.

# Input

## option

Options (not used)

## gdx_surf_ptr

The valid GDX surface database pointer

# Output

## rev_flag

Flag indicating whether or not the surface is a revolution (could not compute the defining data)

## v_revolve

Flag indicating if the revolve direction is the surface's v-direction.

## center

A point on the revolve axis

## vec

The vector of the revolve axis

# Return

          GDX_NOERR
          GDX_ENTITYNOTSURFACE
          Low level error return
          .fi