surface-trim workflow

hi all,
i am still struggling with the basics.
what is the typical workflow to trim a surface with a curve?
to be more precise:
1 planar curve in the xy-plane
2 extrusion surface in z-direction
3 trim curve, planar in yz
now the extrusion surface should be trimmed with the trim curve, projected onto the surface.
also possible: extrude the trim curve, intersect with the extrusion surf, trim
for both workflows, i cant find the appropriate components.
maybe there is a different, more effective workflow...

thanks in advance roberto

Replies to This Discussion

Permalink Reply by Bastian Wibranek on November 6, 2010 at 7:24am

I dont get it.

is it possible to get the definition that you created?

Permalink Reply by Jeff C on February 23, 2015 at 3:58pm

Hello Vicente, thanks much for your instructive post and algorithms on these subjects.

I've built and executed your def. after adding your script code to the VB Component, but received the same errors as a couple on this post, IE:

"Error (BC30451): 'rhutil' is not declared. It may be inaccessible due to its protection level."
"Error (BC30456): 'AbsoluteTolerance' is not a member of 'Rhino.RhinoDoc'."

i hoped you'd please let me know,.
1) how to "omit all the error checking" from the VB component?, AND\OR..
2) how otherwise to have the vb script run error free or complete its task?
3) or lastly, save your time by perhaps uploading your .gh, .ghx file with the working VB script?,

Thanks again for your great! work and assistance,
Jeff

Permalink Reply by maysam on May 23, 2009 at 2:43pm

thanks for the script!!!
But the grasshopper couldn’t understand the boundary of the trim. it still see the original surface. could you please take look at the following picture. Thank and let me know if I’m wrong or any Solution? thanks

Permalink Reply by Vicente Soler on May 23, 2009 at 4:45pm

A trim just 'hides' part of the surface, but it's still there. The subsrf component will extract any portion of the surface even if that specific domain is hidden by the trim.
To filter the unwanted subsurfaces you can use the 'trim inclusion' component + a 'cull patten' component. If you want the bordering subsurfaces trimmed, you can just reapply the previous trim to them.

Permalink Reply by maysam on May 25, 2009 at 12:11pm

thank you Vicente

Permalink Reply by maysam on May 26, 2009 at 4:44pm

hi Vicente, I’m sorry to disturb u, but still I’m straggling. I can’t filter the unwanted surface???!!

Permalink Reply by Vicente Soler on May 27, 2009 at 10:26am

In the following example i check to see if the middle of each subsurface is outside the trim and filter those out. You may want to use another condition for filtering the surfaces, like checking if all the 4 corners are inside/outside the trimmed area.

Permalink Reply by maysam on May 27, 2009 at 12:31pm

thanks a lot, this is great

Permalink Reply by Gabriel on May 29, 2009 at 1:39pm

let's say you wanted to include only those surfaces with all four corners as complete panels but you wanted those edge surfaces with the trims - what's a good way to go about doing this?

I am looking to maintain the curvature of those edge panels and not the UV stepped panels...

Permalink Reply by Gabriel on June 6, 2009 at 2:19pm

Vicente, just wondering if you could suggest a method for testing all four corner points - my attempts seem to test each corner and if any one of the four come up as true, the panel is included...

Permalink Reply by Vicente Soler on June 9, 2009 at 3:03am

Sorry, I've been busy lately. This is one way of doing it:

Since the merge component is broken, i had to do some weird stuff to create the 4 points. Basically I'm inputing to the point component the following sequences: x -> u0,u1,u0,u1; y -> v0,v0,v1,v1.

Permalink Reply by Arthur Mamou-Mani on October 22, 2009 at 5:47am

Hi Vincente,
Thank you very much for all your help.
I m facing a different type of problem i think:
I want to trim a polysurface with a curve that spreads on several of its surfaces...Any ideas?
Also i was just wondering why you needed use "dim" in your script as opposed to the first simpler version you did in this converstation.

Many thanks

Arthur