Power Shelling

Power Shelling (Power Shell) enables the user to offset, inset, and shell a open or
closed polysurfaces in Rhino.  Shelling enables the user to Preview the result before
accepting it.  If the result is not what is desired the Wall Thickness can be changed
or the operation can be Canceled.  Shelling doesn't modify the original object but
creates a new object.  You may want to delete or hide the original object after
shelling or offsetting.

Power Shelling Tip

  1. Don't shell objects with lots of NURBS fillets (precise torii and cylindrical fillets are fine).
  2. Don't shell a NURBS surface with a radius so large that it self-intersects unless it is a
    precise extruded or revolved NURBS surface.
  3. Don't expect Power Shelling to work on all objects.
  4. You need to use the Offset - Extended Surfaces option to offset polysurfaces that are not
    closed (i.e. open shells).

Power Shelling Usage:

  1. To start the command either select "PowerShell" from the menu or type "PowerShell" into the
    Rhino command line.
  2. Pick a surface or polysurface. 
  3. If doing a Hollow operation then pick one or more shell faces.
  4. Type in the radius of the offset/inset/shell.  Note that positive and negative values are
    acceptable.  Negative values are interpreted as insets.
  5. Select the Operation Type:
  6. Select the History option and then the OK button.


Original Object


Power Shell Dialog Box.  Note that you may
preview the results.

 


Here is a shell with a 0.2 radius offset and the front face selected as the shell face. 

 


Here is a shell with a -0.3 radius inset.

 


Offset (not shell) with a radius of 1.0.

 


Inset (not shell) with a radius of 0.2.


Lower Left Original Object.  Lower Right is shell with surface extension.  Top images is
shell with rounded edges.

Offset Solids:

With version 2.0 of PowerShell, you can also created Offset Solids.  Offset Solids are basically
surfaces with a thickness.  To create an Offset Solid, use the following steps.

  1. Start the PowerShell command.
  2. Pick a surface or polysurface. 
  3. Choose the "Hollow w/Extension" option.
  4. Type in the value for the offset.  Note that positive and negative values are
    acceptable.  Negative values are interpreted as insets.
  5. Select the History option and then the OK button.


Original surface (with no offset thickness).


PowerShell dialog box.  Choose Hollow w/Extension option.

 


Offset Solid result.  Notice thickness of object.  A rotated version of the object is shown below.