How to Insert IsoParm in NURBS model like in Maya?

Hey,

Refine SOP. Its not the same as in maya. Yeah thats one of the features in maya that I actually like. Houdini makes up for it with pasted NURBS though.

Cheers,
Nate Nesler

Thanks,
I am a little bit disappointed about this. It's really simple and usefull feature.
May be beter to model NURBS in Maya and via *.iges import it in Houdini?

Out of curiousity how does it work in Maya?

Hey,

Well you select the NURBS surface and then right click to select an iso param and then you can move it around on the surface of the NURBS where ever you want. When you have it where you want it then you click to place it and do the Insert Iso parm operation. I don't like putting in multiple Iso parms like the refine sop does all at once. Plus I can not control the refine sop as easily.

Cheers,
Nate Nesler

Well, I discover smth. You can also put one isoparm using Refine SOP and also can control it position. So it's work normal.
But there are interesting thing. If you model with NURBS in Houdini using order 3, like in Maya, then you'll get smooth problems in render.
order 4 is Ok.
P.S. Sorry my English

Hey,

Check out Pasted NURBS you probably won't go back to maya NURBS modeling afterwards. Its probably the coolest Houdini NURBS feature. You could even change a characters face interactively by creating a network with a switch from different nose NURBS Surface shapes to interactively switch between different characters, generate new ones or 3D morph between them. He He very cool stuff. I suspect you could even use it for crowds. Thanks for the Info on the doing just a single Iso parm with refine sop. I guess it makes it even with maya's insert Iso parm and even more powerful because you can run it through the network. If you aren't already you might try working in the flat wire shaded mode when doing the nurbs modeling or when doing a refine sop because it makes the Iso parms show up nicely.

Cheers,
Nate Nesler

You know that you can click on the isoparm inserted by the refine and drag it arounf interactively.

Yeah I didn't know that but I think I may have just found a bug in 7. When I selected First V it would not like me move it with my mouse but I could with the slider. and when I selected the Second U it would not let me move that one either. But it would let me move Second V and First U. Odd.

Cheers,
Nate Nesler

P.S. I don't know how long you have been using houdini but if you can not get things to update someday its the little red dot button in the top of the interface. If it says something other than always like say never then nothing updates. It can save you alot of headaches in the future. I knew about it back when when I must have clicked it while modeling, and I just about went nuts trying to figure out why nothing would work in the modeler. lol

Suvo
…
But there are interesting thing. If you model with NURBS in Houdini using order 3, like in Maya, then you'll get smooth problems in render.
order 4 is Ok.
…

There is nothing wrong with it. Maya is just using degrees to specify the smoothness NURBS. Remember: order = degree+1
It all has to do with polynomials. The degree is the number of the highest exponent. The order is the number of addends in a full term. E.g.:
f(x) = 3x³+5x²+2x+7
Is a polynom of degree 3 and order 4.
But remember
g(x) = 9*x³+6x
is also an order 4 curve, because you can rewite it to
g(x) = 9x³+0x²+6x+0

So Houdini order 4 curves/surfaces are the same as Maya degree 3 curves/surfaces.
I hope you enjoyed this little math lectue :-)

Actually, in the new help, go to Contents/Geometry Type/Splines and there's a fairly comprehensive yet clear section on all this. I suspect, Matrix, that there's a different GUI approach to things, but it's not less correct or flexible than Maya. It's just different. I'd try getting comfortable with the Houdini approach to it before inferring it's somehow missing something or broken.

Cheers,

J.C.

Hey J.C.,

Sorry I have been on Houdini for over 2 years now. I just never ran into being able to click to move the Iso Parms on the Houdini Refine SOP. I thought I under stood it fully but I did not. However, that said there is still a bug in it. Because when I opened houdini 7 and tried it the first time and could move only First U and Second V. I tried like 20 times to before I closed Houdini 7 and used my spacebar to move the perspective angle around too. When I opened it up the 2nd time and tried the First V decided to work via clicking. Mind you all the sliders worked on all of them. I also have to kill the houdini process after I close it in Houdini 7 because it just hangs in the background after I close it and then if you launch another houdini it makes the process hang after the interface have come up.

Cheers,
Nate Nesler

You're running a beta, consequently there will be some problems, and this should really be discussed in the v7 Early Release forum, not here.

You never mention what version you're running, the OS you're on, but I'll guess windows and the early release un-licensed version. I'm trying to do this in 7.0.141 on Linux and I can't, so hopefully it's fixed.

Cheers,

J.C.