Hi.
I have a torus with radius set to .6,.02, producing a thing ring. I add a copy SOP set to 6 copies with a Uniform Scale set to .7 to create concentric rings. My problem is that each copy's radius gets smaller and smaller and the gutters between each ring get closer and closer. I need the radius and gutters to remain consistent. I tried using a stamp to no avail. Anyone have a solution?

Thanks in advance for any help.

-Matt

Please post up a simple scene file showing the issue > its the quickest way to get a response

Rob

Sorry I could not resist. Sometimes with Houdini the answer lies somewhere else, try making an otl from the file !

Rob

Thanks so much for the quick replies and sample file. This is a great solution to what I was asking… I love how many ways Houdini can skin a cat.

Unfortunately it doesn't solve my problem, since I was simplifying the issue figuring if I could get a torus to work I could fix my issue. Here are more details about what I am really trying to do…

I drew an organic Nurbs curve with about 10 points and “almost” closed it. I then added a resample to add a bunch more points on the curve, then added a fuse to close the curve into an face-less closed wire. I then added a wire simulation, pinned two points, reduced gravity, and added a few fans. This produced an organically blowing wire like it is hanging from a clothes line. I then added a circle and swept/skinned it along the deforming wire to give it some thickness. Finally I add the copy sop to replicate 100 organic lines, each scaling slightly inward, to replicate the client's very specific illustration being used in their campaign.

The result is similar to what I initially brought up with the copied torus… the thickness of each wire gets progressively smaller along with the gaps. I need a way to push each copy farther apart as well as enlarge the circle's diameter being swept along each wire.

Attached is a .hipnc file I have been working on from home. Once I figure it out I will rebuild it in my commercial license at my studio… if this nc file will not work for you guys to check out, I can remote into my office and rebuild it in the commercial version later today.

Thanks a million for helping me solve this. We are new to Houdini, and I think I am going to love this forum as much as I am loving the software!

Regards,
Matt Silverman
Bonfire Labs
San Francisco

I just did a little more digging and found the root of my problem… I forgot to check on the use stamp checkbox. doh.

Now I have the gutters working right by putting a transform before the copy and using the scale from there. But I can not get the stamp to increase the radius of the rings as they go back. Attached is my updated scene.

Another thing that can solve this problem is if I could just render the wire instead of having to add the sweep. Is this possible with Mantra?

Thanks!

I just rendered the wires and they surprisingly worked. So I am good to go. Thanks again for your help!

So I thought I was there… but now I can not change the thickness of the rendered wires. I just tried to simplify the situation by making a new scene with just an open curve. I immediately hit render and get a very thick line. Any ideas on how to control this thickness?

Thanks!

your geometry needs an attribute “pscale” in order to control the thickness, you can either create that with an attribute create SOP or use the Point SOP to do that for you.

cheers,

Manu

Thanks! I found a workaround by adding a PolyWire node to control the thickness. I'll try your advice as well!

-Matt

AFAIK, use an attribute ‘width’ is more appropriate for curves. I never tried the pscale attribute, but i think a WIDTH attribute can be applied on UV of curve when pscale is only applied on points ? I will check it

Thanks! If you wouldn't mind posting your file if you get it to work that would be great. I'm not familiar with the adding a width attribute.

-Matt