Creates a polyline through the control points
of a curve, or a polygon mesh through the control points of a surface.
Steps:
-
Select
curves or surfaces.
-
This creates polylines and/or meshes that have vertices at the original objects’ control points.
Notes
-
The ExtractControlPolygon command is useful if you want to extract control polygons as objects.
-
It is possible to use the ExtractControlPolygon command to create polygon data that you can export and manipulate in a program that handles mesh smoothing.
Mesh > Extract Mesh from NURBS Control Polygon
Mesh > From NURBS Control Polygon Related topics… |
Creates curves that duplicate surface isoparametric curves at specified locations on the surface.
Steps:
-
Select
a surface.
-
The cursor
is constrained to the surface, and isoparametric curve
display at cursor.The draft angle
of the surface displays at the status bar. -
Pick
to create the curve(s).
-
Note: Use the Int object snap for snapping to isoparametric curve
intersections.
Options
Direction
Specify the u-direction
, the v-direction
, or both.
Toggle
Toggles the direction between u and v
.
Notes
-
The ExtractIsocurve command creates the simplest possible curve exactly on the surface in u, v or both directions
. -
The ExtractIsocurve command is useful for creating trimming curves on surfaces. You can make surfaces trimmed along isoparametric curves into untrimmed surfaces with ShrinkTrimmedSrf
. -
You can use isoparametric curves to recreate an existing surface with different parameterization. To do this, extract several isoparametric curves, and Loft
a surface through them. -
If you need to put angled cross sections along a surface, use the Section
command instead of the ExtractIsocurve command. If you need curved cross sections, use the Project
or Intersect
commands. -
The Knot
object snap can be used to create isoparametric curves at exact knot
locations. -
In contrast to the InsertKnot
command, the ExtractIsocurve command creates separate curves that are not attached to the surface. -
If you need to place an object on a surface, use the ExtractIsocurve command to add visual cues or locations that can be snapped to on the surface area and help position the object. Using the ExtractIsocurve command does not change the surface in any way.
Curve From Object > Extract Isocurve
Curve > Curve From Objects > Extract Isocurve Related topics… |
Places point objects at curve control point
or edit point
locations, surface control point locations, and polygon mesh vertices.
Steps:
-
Select
curves, surfaces, or polygon mesh objects.
-
Rhino creates point objects for every control point in the object.
To extract selected points only
-
Turn on the control points
or the edit points
on an object. -
Select
the control or edit points to duplicate.
Point > Extract points Curve From Object > Extract Points
Curve > Curve From Objects > Extract Points Related topics… |
Separates or copies a surface or a copy of a surface from a polysurface.
Steps:
-
Select
the surfaces.
-
The surfaces are separated from the polysurfaces. The remainder of each polysurface will stay joined.
The extracted surface is also removed from any groups to which the original surface may belong.
Notes
-
When you are extracting a surface from the polysurface the ExtractSrf command can save you a lot of time (as opposed to Explode
). This is because it lets you extract only the selected surfaces from the polysurface, and so there is not as much joining work to do afterwards.
Options
Copy
Solid Tools > Extract Surface Geometry Fix > Extract Surfaces (Right click) Main2 > Extract Surfaces (Right click) Popup > Extract Surfaces (Right click)
Solid > Extract Surface Related topics… |
Separates or copies curve segments from a parent polycurve.
Steps:
-
Select
a polycurve.
-
Select curve segments.
Options
Copy
Curve Tools > Extract Sub-curve
Curve > Curve From Objects > Extract Curve Related topics… |
Removes a portion of a curve that is between two selected locations.
Steps:
-
Select
a curve.
-
Pick
a start for the deletion. -
Pick an end for the deletion or enter a length.
Curve Tools > Delete Sub-curve
Curve > Curve Edit Tools > Delete Subcurve Related topics… |
Creates curves that duplicate surface or polysurface isoparametric curves displayed in the wireframe
view.
Steps:
-
Select
surfaces or polysurfaces.
Curve From Object > Extract Wireframe
Curve > Curve From Objects > Extract Wireframe Related topics… |
Creates curves that duplicate the untrimmed boundary and trim curves of a surface as planar curves onto the world x-y plane.
Steps:
-
Select
a surface.
Note: The control polygon determines the sizes of the uv curves.
Curve From Object > Create UV Curves
Curve > Curve From Objects > Create UV Curves Related topics… |