geometry and material variants, instancing in solaris

Variant workflow. Use the Component builder + Geo Variants to build some variants. You'll use the Component Material node to create the mat variants, then packaged them out with the component output. Bake this as a USD.

 

Load your cached out USD. Attach an "explore variants" node and set the mode to explore. Set spacing to zero so they're all at the origin.

Then plug it into an Instancer. Specify the primitives you want to prototype (use in instancer). Make sure you UNTICK "Only Copy Specified Prototype Primitives". The rest is as normal (eg make some points inside the instancer and give it an index attribute).

Now all of your variants are in play.

This seems a bit longwinded, but I guess it does work and fits within a pipeline a bit nicer? It also works nicely with the variant systems that exist in Houdini/Solaris.

BONUS - if instead of using the Instancer in "Point Instancer" mode, you use "Instanceable Reference", you gain access to each and every instance. If you do this, you can actually use the Set Variant nodes to change particular instances, eg. you switch one of them to be a pig and make it red instead of green. Performance does take quite a big hit if you do this though. 

crowds in solaris/karma

 Bring in crowd from obj using SOP Crowd Import node (here it's still packed agents). Create Instanced SkelRoots is preferred I think

Stylesheets don't work with Karma/Solaris (as far as I know!) To target props/shapes in a crowd you're best off using Collections. Here we're making collections of the hammer prop. 

It's important to tick Allow Instance Proxies in Collection!

The syntax is %reference:/path
In the example it's %reference:/crowd/agentdefinitions/ball/shapelibrary/l_hammer

Here's the stage scene outliner thing

Assign the materials to the collection by typing in the name. Eg. %hammer

Be sure to expand the Material Binding and tick Include Descendant Primitives in Collection
You might have to change the Strength to Stronger or Weaker than Descendants too.

I couldn't see a good way to access point attributes (eg. per agent float/int values) but Material X does read them - so I guess use switch RGB and stuff like that?

This seems to be the user data equivalent-

This seems to be the best switch RGB equivalent-

Just plug em in like this - just like Arnold

And ta da...attributes and collections targeting different bits of a crowd!