Trim

Deletes selected portions of an object inside or outside where they are intersected with another object.

Steps:

  1. Select the cutting objects.

  2. Select the parts of objects to trim away.

Options

ExtendLines

When line objects are used as cutting objects, imaginary extensions of the line are used.

This makes it unnecessary to manually extend lines that do not intersect the objects to trim.

UseApparentIntersections

Curves are trimmed in relation to the view. They do not need to intersect in 3-D space. They only need to appear to intersect in the active viewport.

This option does not apply to surfaces.

Notes

Trimmed Surfaces

A trimmed surface has two parts: a surface that underlies everything that defines the geometric shape, and trimming curves that either trim away the outside portion of the surface or cut holes in its interior.

Those trimming curves exist on the underlying surface. The underlying surface may be larger than the trim curves, but you won't see the underlying surface because Rhino doesn't draw anything for the part of the surface that is outside the trim curves.

Only the underlying surface defines the actual geometry of the shape. The trim curves do not define a surface -- they only mark which part of the surface is to be considered trimmed away.

If you have a trim curve that runs diagonally across a surface, the trim curve itself doesn't have any real relationship to the control point structure of the surface. You can see this if you select such a trimmed surface and turn its control points on. You'll see the control points for the whole underlying surface, which doesn't necessarily have any connection with the trim curves.

You can remove the trim curves and get back to the underlying surface using the Untrim commands to remove holes or outside boundaries.

When you have a trimmed surface whose underlying surface is much larger than the outside trimming boundary, you can use the ShrinkTrimmedSrf command to shrink the surface back so that it is only large enough to hold the trimming boundaries and doesn't have a large extra unused area.

trim.png

Main1 > Trim

Geometry Fix > Trim

Menu2.png

Edit > Trim

key-008.gif

Keyboard Shortcut: Ctrl + T

Gray_Book_Open.gif Related topics…

WireCut

Trims a polysurface with a curve similar to cutting foam with a heated wire.

Steps:

  1. Select the cutting curve.

  2. Select a surface or polysurface face.

  3. Pick the first cut depth or press Enter to cut through the object.

  4. Pick the second cut depth, or press Enter to cut through the object.

  5. Select the part to cut away.

Options

Direction (first cut)

X/Y/Z

Constrains the direction for the wire curve extrusion to world x, y, or z.

NormalToCurve

Constrains the direction for the wire curve extrusion to the curve plane normal.

CPlaneNormal

Constrains the direction for the wire curve extrusion to the construction plane z-direction.

Pick

Pick two points to specify the wire curve extrusion direction.

AlongCurve (closed curves only)

Constrains the direction for the hole extrusion along a curve.

Direction (second cut - open curves only)

X/Y/Z

Constrains the direction for the second cut extrusion to world x, y, or z.

NormalToFirstExtrusion

Constrains the direction for the second cut extrusion to the first cut extrusion normal.

Pick

Pick two points to specify the second cut extrusion direction.

Flip

If Yes, changes the selected and highlighted part that will be cut away and deleted from the currently highlighted part to the other part.

KeepAll

If Yes, keeps all parts of the solid.

wirecut.png

Solid Editing > Wire cut

Menu2.png

Solid > Solid Edit Tools > Wire Cut

Gray_Book_Open.gif Related topics…

Untrim

Removes trims and surfaces joined at the trim curves from a surface.

Steps:

Options

KeepTrimObjects

Yes

The original trimming objects are separated and retained.

No

The trimming objects are deleted. This also deletes any geometry attached to the edges of the boundary.

All

Removes all trimming curves if selecting an edge of a trimmed surface.  If a hole edge is selected, then all holes on the same face will be deleted.

untrim.png

Main1 > Untrim Surface (Right click)

Geometry Fix > Untrim Surface (Right click)

Menu2.png

Surface > Surface Edit Tools > Untrim

Gray_Book_Open.gif Related topics…

RemoveEdge

Untrims selected surface edges.

Steps:

Options

KeepTrimObjects

If Yes, the original trimming objects are separated and retained.

Mode

ReplaceWithLine

Replace the edge with a line between the edge end points.

ExtendSideEdges

The two surrounding edges extend.

The edges must meet within surface boundary to give successful results.

RemoveEdge.png

Surface Tools > Remove Surface Edge

Menu2.png

Surface > Edge Tools > Remove Edge

Gray_Book_Open.gif Related topics…

SubCrv

Trims a curve by specifying two points on the curve.

Steps:

  1. Select a curve.

  2. Pick a new start for the curve.

  3. Pick a new end or type a length for the curve.

subcrv.png

Curve Tools > Sub Curve

Menu2.png

Curve > Curve Edit Tools > Subcurve

Gray_Book_Open.gif Related topics…

MeshTrim

Deletes selected portions of a mesh inside or outside where they are intersected with another object.

MeshTrim.png

Mesh > Mesh Trim

Menu2.png

Mesh > Mesh Edit Tools > Mesh Trim

Gray_Book_Open.gif Related topics…