Control Visibility and Procedural Workflow

[dutchpancakes]

Hi Guys,

I've just started with Houdini and watched the CMI Fundamentals video. All these procedural techniques get me really excited. The stuff I have been trying to solve scripting in Maya, and all the headaches of versioning, seem to be solved with this amazing software.

One question is, once you've build an environnement, like in the CMI Fundamentals video (the railroad), there's a lot of possibilities to change the landscape, the roads will procedurally change with it, and you can change the curve that drives the road etc. etc. I'm wondering if there's any cool way to define tweakable parameters? Would you color the nodes, or link them through to one control node? After setting up a massive scene, I can only imagine you come back after 2 months, and it's hard to oversee what were the interesting parameters to animate/tweak, without having to go inside each node and finding out what happens.

The other question is, Houdini seems to be known for doing FX work, particles, fluids. If I knew before about all these procedural modeling techniques I would have jumped on it much earlier. Are there any studios around the world that use Houdini solely for it's procedural workflow, it seems all the job postings are always FX related.

Thanks

[kgoossens]

I'm wondering if there's any cool way to define tweakable parameters? Would you color the nodes, or link them through to one control node? After setting up a massive scene, I can only imagine you come back after 2 months, and it's hard to oversee what were the interesting parameters to animate/tweak, without having to go inside each node and finding out what happens.

Have you been looking at digital assets? This allows you to create new functions/nodes by collapsing a graph into a single node and it also allows you to create an interface for it.

[dutchpancakes]

Have you been looking at digital assets? This allows you to create new functions/nodes by collapsing a graph into a single node and it also allows you to create an interface for it.

Didn't know about Digital Assets, but they seem to be exactly what I was looking for! Thanks!

[Annon]

You don't need to necessarily create a digital asset, you can just stick everything in a subnet (shift + C I think on all the nodes you want inside) and promote some parameters to this top node. Or you could scrap that and stick the parameters at the object level, so you don't even need to jump inside. If I've got something that might only be used for a certain sequence (and I have time) I'll usually just promote all the attributes to the top. Have a play with the ramp parameter in VOPs (it's a node that'll create a UI parameter), they're really easy to tweak what you want.

On modelling, yes it is used a bit for procedural stuff, but often because there's an entire modelling department who don't use houdini, it'll usually be done manually or at least tweaked by a modeller. Cities and large landscapes might be done in houdini if the 3d leads are more technically aware though...

[dutchpancakes]

I'll have to do a little more research on these things, I've created a subnet, but propagating the parameters seems to be greyed out for me. There must be a few steps and concepts I'm still missing, but I'll get there.

Thanks for your help, it's much appreciated.

[ryew]

Peter Quint posted a good HDA tutorial not too long ago here

You can also check out the 4-part Digital Asset tutorial on Jeff Wagner's Old School Blog; they're from 2007 but still good foundation:

part 1

part 2

part 3

part 4

Hope that helps

[dutchpancakes]

Awesome, that video by Peter Quint made a lot of sense.

Is there a way to connect part of a vector parameter, drag and drop style, into the edit parameter interface? In Peter's video he shows a work around where you write a channel connection (ch("../...)), is that the only way?

On that note, does that ../ mean going up one level? If I would want to connect a parameter a couple of levels down, to the subnet at the root, I would write something like ch("../../../../subnet/newlyMadeParameter"), or maybe I'm confused?

Thanks