# NAME

GDX_RULED_SURF - Ruled Surface

# GENERAL DESCRIPTION

A GDX Ruled Surface represents a surface formed by moving a line connecting points on two parametric curves from a sart point to a terminate point on the curves.

# DDF SPECIFICATION

    entity 12:0   GDX_RULED_SURF   "Ruled Surface" {

    char
    END_FLAG;

    ptr
    FIRST_CURVE
    reftype = (P_CURVES);

    ptr
    SECOND_CURVE
    reftype = (P_CURVES);

    };

# FIELD DESCRIPTIONS

END_FLAG

Flag indicating whether the first rail curve should be reversed or not.

PDX_TRUE

The second rail curve should be reversed.

PDX_FALSE

The second rail curve should not be reversed.

FIRST_CURVE

The database pointer of the GDX curve corresponding to the first rail curve. The allowable GDX entity type/forms consists of the parametrically defined GDX curve entities as defined by the P_CURVES ptrlist variable in gdx.ddf. For reference, these entities are:

GDX_CONIC
GDX_NURB_CURVE
GDX_ARC
GDX_SPLINE_CURVE
GDX_POLYLINE
GDX_COMP_CURVE
GDX_OFFSET_CURVE
GDX_TRIM_CURVE
SECOND_CURVE

The database pointer of the GDX curve corresponding to the second rail curve. The allowable GDX entity type/forms consists of the parametrically defined GDX curve entities as defined by the P_CURVES ptrlist variable in gdx.ddf (see FIRST_CURVE field above).

# PARAMETERIZATION

The parameterization is the same as that used for the IGES Ruled Surface Entity (Type 118) and can be found in Section 4.15 of The Initial Graphics Exchange Specification (IGES) Version 5.2.

# PARAMETRIC RANGE

The GDX Ruled Surface is defined over the following parametric range: 0.0 <= u <= 1.0 0.0 <= v <= 1.0

# RESTRICTIONS

None.