Surface trimming / boolean difference in Alias?

So I’ve been learning Alias on my own by forcing myself to do it for my projects. Currently, we are doing a 3d printing project, and I am making a hand tool for filing charcoal pencils for figure drawing.

Is there an easy way to do surface trimming? In rhino, I know you can do boolean difference and easily get rid of these protruding spikes. However, I’m having to carefully draw a curve that matches exactly onto the surface intersection (near impossible), projecting, then trimming, and I’m thinking of sanding it off when I get it printed (counter productive).

Any helps?

If there is surface intersecting to all those ribs…just intersect them together ( surface& ribs) & trim

That’s right, you have to first intersect them and then trim. Trimming straight away is to tricky for Alias :laughing:

oh thanks. i just did it, but there are still tiny little nubs poking out. :confused:

increase surface degree…

sorry, I’m not exactly sure what that means/how to do that. I’m trying to digest all this modeling terminology that I see in tutorials, but it’s really not processing that well right now.

INTERSECT : Palette > surface edit > curve on surface > intersect
(reading the prompt line at the top gives you the basic workflow)

  1. select the bulk of the surfaces that you want to intersect and eventually trim(the spikes)
  2. hit GO or the space bar(short cut for active options)
  3. select the intersecting surface(s).

not to scare you as a newbie, but be careful not to select a surface twice. it will create multiple curve on surfaces(trimming curves) and that tends to be bad.


its a shame this is not obvious… but there is a newer feature in the trimming tools called “3d trim” it was a plug in for years and now its part of the software… it removes the project a COS step onto the surface. unfortunately this does not work for intersecting but its a time saver.

  1. go to to view that you would normally project a curve from.
  2. select surfaces
  3. select curves
  4. tag the surface with a keep, discard, divide
  5. hit enter

oh yeah, … booleans.
Alias has booleans but highly NOT recommended. :smiley:

its not that it cant do it, it just requires you to work in a different way from the typical NURBS modeling. no real advantage.

the tools can be found in the surface edit tab of the palette. (stitch and Shell)
first you would have to stitch the surfaces then use the shell tools to subtract, intersect or union.