# Synopsis

PDX_MSGT igeo_Convert128ToSurface(long option, MDA_PTR db_ptr_128, EAM_STACK *stack, int model, MDA_PTR *db_ptr)

# Purpose

Convert an IGES NURBS surface (126) to an IGES surface

# Description

Converts an IGES NURBS surface to an IGES surface based on the form of the IGES NURBS surface, within the IGES Geometry subsystem. If the form of the IGES NURBS surface is 0 than the IGES NURBS surface data is tested to determine the form of the IGES NURBS surface. If the form can not be determined, then the IGES NURBS surface is created as is in the new model. By default, the IGES NURBS surface matrix is concatenated with any matrix on the attribute stack and applied to the data. If the IGES NURBS surface is determined to be a cone, cylinder, sphere, or torus, the surface is mapped to an IGES surface of revolution (120). All subordinate entity surface curves are mapped to the form of the NURBS curve for that surface type. If a conversion error occurs any data created during the conversion is deleted and no IGES surface entity is created. The IGES NURBS surface entity must be a valid IGES definition. The conversions are exact to the precision of the input data and to machine precision.

# Input

## option

### IGES_NOMATRIX

Do not apply entity matrix to data

## db_ptr_128

The valid IGES NURBS surface entity database pointer

## stack

The entity attribute stack

## model

The model to create the IGES surface in

# Output

## db_ptr

The IGES surface entity database pointer

# Tolerances

          MODEL_SPACE_PNT_TOL
          ZERO_TOL
          TANGENT_TOL
          CURVATURE_TOL
          DERIVATIVE_TOL
          COLLINEAR_TOL
          .fi

# Return

          IGEO_NOERR
          IGEO_SURFACEISNOTNURBS
          Low level error return
          .fi