Hi!

I need some insight into the Houdini's NURBS experience…

I'm proficient in the use of Rhino 3D for NURBS modeling of industrial design type objects. I then generally export meshes to Lightwave for poly object cleanup, basic part naming and materials, and then Messiah for animation and rendering (and Fusion for compositing).

I'm tired of running various specialist apps and would really like to have these things integrated so that when changes are made upstream, then it all just gets factored in instantly and you hit render again and have yourself a life!

Years ago 3DS Max did this rather well for me, and the modifier stack was often beneficial (I did not do NURBS back then). Today 3DS Max still does not do NURBS in any way I can use and I'm not that keen on investing into 3DS Max after which I must still add a $1,000 NURBS modeling plugin.

Maya seems to be a fairly good all-rounder tool, but I just can't get my mind unglued from the procedural benefits Houdini offers. Not to mention the effects of Houdini Master. And I can't say that I'm not drawn to using Mantra for rendering.

Question is: If I do become proficient with Houdini, can I make it fly through advanced NURBS modeling tasks? I understand the incredible benefit of procedural modeling, but if it comes at such a hit to modeling efficiency as to be restrictive…

It's not about the software's ability to do something but how it does it: how efficient, how editable, how stable, how well it then integrates into the scene setup and animation and effects, how easy to control details, etc., etc.

Anyone have experience, or know some pros using Houdini for NURBS?

I know I can try Houdini for myself, but what I need to know I can only know once I'm proficient with it and that will obviously not be the case while trying it out. That's why I'm asking others who may have experienced NURBS success with Houdini?

Hi Paul,

I have bad news for you, sorry about that - NURBS in houdini are ok only for simple modeling projects. When it comes to complex operations such as trims or surface intersections it lacks accuracy and speed. The limitations very quickly drove me mad and I was forced to use Rhino only for those two. (btw. Houdini doesn't support multiple trims on one surface). In addition viewport it's not imho as intuitive as in Rhino (especially selections).
On the other hand you can improve tools yourself (as I did in the end with python and sops tweaks), unfortunately you can't workaround everything, it tends to be slow in heavier scenes. The only solution then is to port the code to HDK. Sadly I wouldn't expect any improvements in the next major builds down the road, since NURBS have very low priority in the houdini development and after all it is mainly a vfx software.
:?

kuba
NURBS in houdini are ok only for simple modeling projects.

Thanks for sharing your experience!

Anyone here routinely export NURBS from other apps to Houdini? Or is mesh export the standard workflow?

Iges is currently the best option. From rhino if I remember correctly softimage settings gave good results.

kuba
Hi Paul,
(btw. Houdini doesn't support multiple trims on one surface).
:?

You have some good points but are you sure about just that? I´m working with a nurbs model right now with what seems like multiple trims but perhaps I misunderstand you.

Hmmm, could you post a hip file, i submitted an RFE over a year ago so maybe it's been improved. What i meant is that you will not be able to trim again a surface (project a new curve and trim) if it is already trimmed.

I think you just need to do all your projections first and then apply one trim.
But you are basically right Houdini Nurbs lack accuracy and need some love.
Not expecting it to happen though. Your best route for complex models is via rhino.

Simon
Your best route for complex models is via rhino.

But the path from Rhino to Houdini using IGES is fine no matter what you modeled in Rhino?

Are there problems with imported IGES parts? For example an IGES file I imported has 5 parts which I'm doing stuff to in Houdini. Now I need to go back to make a serious change on the base NURBS object in Rhino and then export again, but this time there are 7 parts. Will the object replacement in Houdini behave correctly? Or will I need to manually sort and assign nodes to the parts again? That sort of thing.

The biggest problems we've had is with CAD models at very high precision, when they come in even to Rhino you get failed trim curves, that gets worse once imported into Houdini. Can't comment about what would happen if you are building from scratch in Rhino.

Kuba , I do as Simon meaning I first project everything that needs to be trimmed then do it all in one trip sop.

Paul,

Don't know if this is still relevant, but I found that importing an iges model into Houdini quickly bogged it. It seemed that every single little patch was it's own nurbs object. Made it very difficult to work with. Using the Nurbs modeling tool to export an OBJ file worked much better.

jimc
Paul,

Don't know if this is still relevant, but I found that importing an iges model into Houdini quickly bogged it. It seemed that every single little patch was it's own nurbs object. Made it very difficult to work with. Using the Nurbs modeling tool to export an OBJ file worked much better.

Thank you for posting your experience! It is relevant for any future plans involving Houdini, but not right now. I have for now reverted to using separate packages which specialize. For instance, using Silo for subD modeling and importing that into messiah Studio for staging and rendering.

I have all but given up on finding a suitable all-round package which truly excels at most aspects of 3D. Modo, although still lacking animation features, seems to be making steady progress. The closest I have seen must be Maya. I do entertain similar hopes for Houdini, but perhaps in a future version?

I do not know exactly what the vision of the Side Effects team is for Houdini.

Very often our thoughts in these matters are misplaced because we do not share the vision and challenges of the software creators. Sadly and practically, we need to work with what is at hand instead of fumbling with dreams of what tools might someday be.

Pardon my drama… I've just read two exciting chapters of The Three Musketeers to my family. ops:

Paul_Newman
Very often our thoughts in these matters are misplaced because we do not share the vision and challenges of the software creators. Sadly and practically, we need to work with what is at hand instead of fumbling with dreams of what tools might someday be.

I love your salad dressing.

spoogicus
I love your salad dressing.

Thanks! Nice to know!

Paul_Newman

spoogicus
I love your salad dressing.

Thanks! Nice to know!

Is that code for something?