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.
- Selecting Polysurface in the UseExtrusions command turns off Use extrusions when possible in Options > General.
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.