So, I'm new to Houdini Engine and I'm a little confused as to how inter-asset connections are made. For example: I want to make an asset the creates a pyro sim. I want to then make an emitter asset that connects to the pyro sim that feeds it emission data. I would also want to make a collision asset that feeds the sim collision data. As I understand Houdini Engine assets should be able to connect with each other, but so far I can't get them to do that. Is a set up like this possible or is my approach to concept wrong?

Houdini Engine supports Object and SOP assets. And those assets can be interconnected. When the assets are connected, geometry data is passed from one asset to the next. So it's not possible to connect DOP assets together.

If your emitter and collision asset can be made as an Object or SOP asset, then it should be possible to do what you want. This means your emission data and collision data have to be in the form of some kind of geometry. The pyro sim would also have to be a Object or SOP asset.

You'd then expose two inputs from the pyro asset, which is typically done through Object Merge. Through Houdini Engine, connect emitter asset to one input, and collision asset to another input. This gives you access to the emission and collision geometries inside the pyro asset. You can then use those geometries to affect your pyro sim.