Command: polymerge

Syntax

{ <entity> = } polymerge <elist>

Description

Create one or more polygon graphic entities from the result of a merge of other polygon entities.

Parameters

• <entity>
  An entity or gstructure identifier. The resulting polygon entities will be given this name. This can be an entity array for multiple entity assignment.

• <elist>
  A group/entity list defining the operands of the Boolean operation. Only polygon entities are considered.

Switches

• -alph=<num>
  An alpha transparency factor between 0 and 1. A value 1 implies fully opaque, 0 means fully transparent (therefore invisible). The default is 1.

• -br=<num>
  A brightness factor between -1 and +1. A value 0 means normal, -1 means very dark (black), +1 means very bright (white). The default is 1.

• -col=<color>
  The color of the polygons. If included, this will override any color defined in the linestyle (-ls) or fillstyle (-fil). If omitted, the value no_change is used.

• -ff
  Fix the fill color of created polygons so that they are unaffected by subsequent modifications to the entity color.

• -fil=<fillstyle>
  The fill characteristics of the polygon interiors.If omitted, the polygons are not filled. Note: <fillstyle> can be a fillstyle, color, tile, hatchstyle or graduation.

• -fr=<num>
  Define a fragment number for the entity. If omitted, the default fragment def_fragment is used.

• -g=<groups>
  The graphic groups of which the entities are to be member.

• -h
  Without this switch all polygons with holes are assumed to be valid and are not checked for consistency. Add this switch to resolve polygon/hole anomalies with suspected overlapping edges. The hole polygons will be merged using the boolean difference operator.

• -k=
  By default, when new polygons are created, vertices between consecutive parallel edges are automatically removed to create one single edge. The addition of this switch will suppress this action thus retaining original vertices.

• -ls=<linestyle | color>
  The linestyle of the polygon edges. This can be a linestyle or a color. If omitted, the current modeling color def_color is used.

• -pc
  Compute the para-centroid of any created polygon and make it the polygon’s origin.

• -ra=<num>
  Define a rank for the entity. If omitted, the default rank def_rank is used.

• -sub
  Create any resulting polygons which are islands within holes as sub-polygons of the holes. This is the default behavior. To create islands within holes as top-level polygons use -no_sub.

• -th=<num>
  The thickness of the polygon edges. If included, this will override any thickness defined in the linestyle (-ls) or hatchstyle (-fil) if applicable.

• -tol=<num>
  A closeness tolerance for edge and vertex matching. If omitted, a suitable tolerance is merged. Care should be taken to ensure that any supplied tolerance is not too big, since polygon vertices are sometimes adjusted to a grid of this tolerance during edge intersection causing unpredictable results.

• -xg=<group>
  Compute polygons created by the intersection of the polygons being merged, and add them to <group>.
  This is useful for determining whether or not any of the merged polygons overlap.

Notes

This command creates one or more graphic entities of type polygon. Any input polygons with coincident or crossover edges will produce undefined (probably incorrect) results.

The Boolean operation used to produce the merge is a union of all polygons in <elist>.

Any holes resulting from the boolean operation will be created as unnamed child holes.

All polygons (including holes and islands) created by a polymerge command form the contents of the group these.

Polygons which reduce to a line for one reason or another are ignored.

The system numeric found records the number of polygons created by the polymerge command. Holes and islands are excluded from the count.

Examples

Merge all polygons in a group ga (into these).

polymerge ga

See Also