Hello all,

first of all, i am new to Houdini.

I am currently planning a more complex project.
Most of it(if not anything) should be done in Houdini and it is, simply said, pretty much a set of PyroFX.
In view of the rendering process, i would like to split the scene in different parts, so i can easily adjust most of it in Nuke in compositing. As an example i think about having shattered stones on the ground, levitation up at a given point in the scene. Those stones should be lit by an fire kind of orb floating around.
Right to the point, my main question here is the stuff regarding the lighting information.
In case i do want to render out the floating stones for themselves, will i need to have them in the same houdini scene to get the lighting information from the pyro orb? I guess it is possible to render out just the stones WITH the correct lighting from the orb but WITHOUT the orb itself?
What would be the best way to do so? Because i am going to have more PyroFX all intendet to light up the scene as a whole.
Do i need to set up anything in one hipfile? Or is there some kind of cool stuff i do not know about, yet?
I'm afraid(almost sure^^) the scene could get too big and not to be handled anymore soon…
Generally said i am asking if there is a good way to split up my scene in different stuff/models and when it comes to rendering each model for itself, i of course do want the lighting take effect for every part of the scene.

That really puzzles me and i hope, someone can help me!

Thank you and
cheers!

you can keep everything in the same scene if you are using packed disk/packed alembic workflow
or for tidiness you can create lighting scene
bring in all your geo and all the caches as packed disk/packed alembics, keep them as bbox or none for viewport if they are heavy, just set up your material, light relationships, different mantras for individual layers, with other objects as matte or phantom

you scene will be super light as it contains just references to the heavy assets and caches, nothing has to be displayed in the viewport unless you need to, mantra will load whatever needed at rendertime

Like tamte I definitely lean towards creating a lighting scene with everything brought in as packed.

Houdini offers many tools aimed towards managing complex scenes, although unfortunately there's not one method to rule them all. Some possible ways of organising things:

Bundles
Use bundles for managing groups of light and objects. This is one of the most straightforward ways to control what objects and lights are assigned in a Mantra node. You can also use smart bundles to automatically assign nodes (e.g. all nodes with RENDER* in their name), however use that one with care; heavy scenes plus wildcards = bad things). So you can create a bundle for floating stones, environment, pyro, environment lights etc

Data Tree
If all your objects are packed you can use the object appearance data tree to organise, display and assign materials to your packed objects. It's really nice as you can assign packed edit nodes by right clicking on the object in the data tree and also group object in network boxes, so for example all the environment objects and lights appear in one network box, fx in another etc. Purely visual, but a nice way of organising things. You can also do light linking for the objects.

You can also use the Light bank to organise the lighting, however this is the part of the light bank that I find the most flaky; going to the pane replaces light categories, and the tag field is kinda broken as it automatically appends a digit to your category. So kind of edge towards saying, done use this one,


Categories
The final way of organising thing which springs to mind is categories, so you can group lights into categories and then use the categories rather than the individual lights for light linking. While in theory this sounds useful, and the docs suggest that this will be the future, there's no nice interface for assigning and managing categories as yet so I'd steer away from them for now.


So many ways to skin the proverbial cat in terms of managing complexity. Form my 2cents I'd suggest:

• Create a separate lighting scene.
  
• Load all the objects in as packed.
  
• Assign materials to the packed objects
  
• Use bundles to manage lights and objects
  
• Use the Object Appearance to manage visibility in the viewport.
  

TLDR: I agree with tamte

You guys are awesome, this really is helping me.
I will definitely take a deeper look at your suggestions.
Thank you so much!

Sebastian