# Create surfaces

A surface is like a rectangular stretchy rubber sheet. The NURBS form can represent simple shapes, such as planes and cylinders, as well as free-form, sculptured surfaces.

All surface creation commands in Rhino result in the same object: a NURBS surface. Rhino has many tools for constructing surfaces directly or from existing curves.

All NURBS surfaces have an inherently rectangular organization.

Even a closed surface such as a cylinder is like a rectangular piece of paper that has been rolled up so two opposite edges are touching. The place where the edges come together is called the seam. If a surface does not have a rectangular shape, either it has been trimmed or the control points on the edges have been moved.

## Closed and open surfaces

A surface can be open or closed. An open cylinder is closed in one direction.

A torus (donut shape) is closed in two directions.

## Create surface primitives

##### 3DFace

Creates mesh or SubD faces that can be standalone or added to an existing mesh or SubD.

##### Plane

Draw a rectangular planar surface.

##### Box

Draw a solid box.

##### Sphere

Draw a solid sphere.

##### Ellipsoid

Draw a solid ellipsoid.

##### Cone

Creates a surface cone.

##### TruncatedCone

Draw a NURBS truncated cone.

##### Cylinder

Draw a polysurface cylinder.

##### Torus

Draw a NURBS torus (donut shape).

## Create a surface from points

##### PlaneThroughPt

Fit a rectangular planar surface through points.

##### SrfControlPtGrid

Draw a surface from a grid of points that represent surface control points.

##### SrfPt

Draw a surface from three or four corner points.

##### SrfPtGrid

Draw a surface from a grid of points that lie on the surface.

## Create a surface from curves

##### DevLoft

Creates a single developable surface between two rails.

##### ExtrudeCrv

Drive closed planar curves in a straight line.

##### EdgeSrf

Create a surface from two, three, or four curves.

##### Fin

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

##### Loft

Fit a surface through profile curves that define the surface shape.

##### NetworkSrf

Fit a surface through a network of crossing curves.

##### Patch

Fit a surface through curves and point objects.

##### PlanarSrf

Create a planar surface from planar curves.

##### RailRevolve

Revolve a profile curve around an axis and along a rail curve.

##### Revolve

Create a surface or SubD by revolving a profile curve around an axis.

##### Ribbon

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

##### Sweep1

Fit a surface through profile curves and one edge curve.

##### Sweep2

Fit a surface through profile curves and two edge curves.

## Create a surface from other surfaces

##### CutPlane

Create planar surfaces through objects at specified locations.

##### Drape

Create a surface through the intersections of objects and points projected toward the construction plane.

##### OffsetSrf

Copy a surface parallel to the original.

##### VariableOffsetSrf

Copies a surface in the normal direction with different distances at specified locations.

##### UnrollSrf

Flatten (develop) a surface or polysurface with curvature in one direction to a planar surface.

## Other methods

##### Heightfield

Create a surface based on gray-scale color values in an image file.

##### MeshToNURB

Duplicate each mesh face with a NURBS surface.

##### Symmetry

Mirror a copy of a curve or surface with continuity.