# Synopsis

PDX_MSGT gdx_NurbSurfImproveParams(long option, MDA_PTR gdx_ns_ptr, int *mod_flag)

# Purpose

Improve parameter uniformness of certain Nurb surfaces.

# Description

This function attempts to improve the uniformness of the parameterization of a Nurb surface which has internal knots of multiplicity equal to or greater than degree. That is, it looks at surface segments (u and v strips) between knots of multiplicity equal to or greater than degree, and it changes (scales/translates) the knot values to better reflect the model space length of the surface segment in the corresponding direction. This is a precise reparameterization; no approximation is done. Hence, the geometry does not change, but the surface derivatives and parameterization do change. This function is particularly useful to apply to Nurb surfaces which were originally created as a quilt of polynomial patches in a non-Nurbs system, and then converted to Nurbs.

# Input

## option

Not used.

## gdx_ns_ptr

The Nurb surface.

# Output

## mod_flag

Flag indicating whether or not surface knots and bounds were modified: = 0 : Nothing modified. = 1 : u-knots and possibly u-bounds modified. = 2 : v-knots and possibly v-bounds modified. = 3 : both u-knots and v-knots were modified, and possibly the corresponding bounds.

# Return

          GDX_NOERR
          Low level error return
          .fi