Polysurfaces

A polysurface consists of two or more surfaces that are joined together. A polysurface that encloses a volume of space defines a solid.

Solids are created anytime a surface or polysurface is completely closed.

Some Rhino commands, such as Pyramid, Cone, and TruncatedCone, create polysurface solids.

Related commands

Select polysurfaces

SelPolysrf

Select all polysurfaces.

SelClosedPolysrf

Select all closed polysurfaces.

SelOpenPolysrf

Select all open polysurfaces.

Draw polysurfaces

Boss

Extrude closed planar curves normal to the curve plane toward a boundary surface where the boundary surface is trimmed and joined to the extruded objects.

Box

Draw a solid box.

Cone

Creates a surface cone.

Cylinder

Draw a polysurface cylinder.

Fin

Extrude a curve on a surface in the surface normal direction.

Pipe

Create a surface, polysurface, or extrusion object with a circular profile around a curve.

Pyramid

Draw a pyramid.

Rib

Extrude a curve in two directions to a boundary surface.

Ribbon

Offset a curve and create a ruled surface between the curves.

Slab

Offset a polyline, and extrude and cap the result to create a solid.

TruncatedCone

Draw a NURBS truncated cone.

TruncatedPyramid

Draw a pyramid whose apex is truncated by a plane.

Extrude curves into polysurfaces

ExtrudeCrv

Drive closed planar curves in a straight line.

ExtrudeCrvAlongCrv

Drive closed planar curves along a path curve.

ExtrudeCrvTapered

Drive closed planar curves in a straight line tapering at an angle.

ExtrudeCrvToPoint

Drive closed planar curves tapering to a point.

Extrude surfaces into polysurfaces

ExtrudeSrf

Drive surface edges in a straight line to create a solid.

ExtrudeSrfAlongCrv

Drive surface edges along a path curve to create a solid.

ExtrudeSrfTapered

Drive surface edges in a straight line tapering at an angle to create a solid.

ExtrudeSrfToPoint

Drive surface edges tapering to a point to create a solid.

Extrusion objects

The Box, Cylinder, Pipe, Slab, Tube, and ExtrudeCrv commands can create polysurface or extrusion objects.

In models containing large numbers of polysurfaces, performance can be sluggish due to the relatively high demand on resources. If the same objects are made in Rhino as lightweight extrusion objects, these models are more responsive and consume less system memory.
The UseExtrusions command controls the use of lightweight extrusion objects. To make commands that normally create extrusions create polysurfaces, select the Polysurface option.

Related commands

UseExtrusions

Specify whether extrusion objects or polysurfaces are used when extruding straight‑sided objects.

The UseExtrusions command controls the use of extrusion objects.

When UseExtrusions is turned on, Rhino commands that create simple solids and surfaces will use extrusion objects when possible.
When UseExtrusions is turned off, these commands will create surface and polysurface objects.
Turning off UseExtrusions does not change existing extrusion objects.

ConvertExtrusion

Convert extrusion objects to surfaces and polysurfaces.

Polysurfaces

Related commands

Select polysurfaces

Draw polysurfaces

Extrude curves into polysurfaces

Extrude surfaces into polysurfaces

Extrusion objects

Related commands

See also