Extrude curve does not make lightweight extrusion

In my Rhino 5 - there is no Extrusion objects, there is only polysurfaces. Is there a way to add this option ? I attach a file for example (from user manuel level 1 page 112) Move.3dm (200.5 KB)

Hi @rachelre, it works here. Try out if globally enabled using _UseExtrusions command.


Hi Clement, Thank you very much. I have tried UseExtrusions command, and it is working, but next time again I have same problem. Is this command is one time using?

Hi Rachel, normally this setting should stick between sessions, so if you set i once from the commandline it always should use extrusions if you extrude. Please try this:

  1. Set _UseExtrusions to Extrusion from the commandline
  2. Extrude a rectangle
  3. Select the result and run _Properties and click on the Details button
  4. It should list that the object is an extrusion
  5. Close Rhino, reopen it and do step 1-4 again

Is the result an extrusion or polysurface ?

Sometimes Rhino cannot create an extrusion, but with a rectangle it should always work. Maybe you should post the curves when it does not work with a specific curve.