hello houdini people !
I started learning houdini about 2 months ago.
This is my first post here, because I ran into a problem witch I can't solve and hope you guys can help me out.
I made a nurbs surface of 3 curves. Then I tried to carve the skin surface 3 times to obtain some holes. Then I want to merge all the 3 carves intro one, and all to be visible, and it doesn't work. Each individual carve SOP works fine, but the merge I think messes things out. Is there any way to solve this problem?
I posted a file attached.
Thank you !

Hi and welcome,

I attach a hip with 3 solutions to the problem. The best one is to use a polygonal model instead of NURBS.
If you do want to stay with NURBS, then you shouldn't branch the modeling network but go in a linear fashion and just carve different primitives (you'll see in my file that different Carves have primitives specified in the Group field).

Dragos

wow thank you dude ! thank you for all three solving versions. I thought it might be a problem when branching the carves, because i think Houdini couldn't figure out in the way I did it. Multiple carves I think is confusing simultaneous, but I still think I can be solved in someway to have al the U and V independent over the surface, without being constrained by primitive groups. Anyway I'm so happy right now that I learned something. Otherwise I like nurbs far better because I can still control the position and the shape of the holes. The downside is that i can only move between the group domain of each carve. The polygon version is cool for a fixed modeling. By blasting the faces I cant slide the holes anymore across the surface. I think it can be done with nurbs and at the end of the chain somehow to add a convert to poly SOP, when a polygon structure is really needed, thus retaining the posibility to move the holes in a nurbs fashion.

Noroc Dragos ! Romanu la nevoie se cunoaste ! Mersi mult ! Ma bucur ca mai sunt si de-ai nostri pe aici . Ti-am luat id-ul de mess de pe forum si ti-am dat add. Poate apucam sa mai vorbim. Am vazut ca esti la DSG. Tot respectu ! Esti tare.

Here are two more solutions that provide a greater degree of flexibility.

The first option is to use the Paste sop instead of carve, which doesn't chop up the base surface like the carve sop does. This way you can have multiple patches on a single base surface. You declare the base surface in the second and third paste sops by assigning primitive 0 as the “Feature Group”.
I left the patches as a kind of exploded view. You can Blast those away or put them to use.

The second option is to use Surfsect sop, which provides boolean operations on an open nurbs surface. This method means you are not restricted to square shapes.