Loop Points Element (LOOPTS)

Primitive Element

Description:

A LOOPTS element holds a set of pointers to the individual Point (POIN) elements which define each vertex of a Polyhedron Loop (POLOOP). These pointers are stored in the VXREFS attribute of the LOOPTS. The POINs referenced are themselves stored under a Polygon Point List (POLPTL) element.

The points referenced by VXREFS must be stored under a POLPTL under the relevant POLYHE or NPOLYH. To preserve the integrity of the primitive, points stored elsewhere will not be considered.

A POLOOP can hold multiple LOOPTS elements, each LOOPTS being limited to a maximum of 500 POINs. The order of points round a loop is in member list order of each LOOPTS in turn.

The INVIS logical array determines the visibility of edges. The points referenced by this array correspond to those referenced by the VXREFS array. If the INVIS pointer is set to False for any point (or, by default, is unset), the edge between that point and the preceding point will be visible; if set to True, the edge will be invisible.

Attributes:

Legal Owners:

Polyhedron Loop Element (POLOOP)

Legal Members:

None

A POIN referenced from a LOOPTS with the INVIS flag set to True behaves like an IPOIN in a POGO, for further information, refer to Polygon Element (POGON).