When creating a fluid sim,I see in the scene level that a DOP network is created with a bunch of attributes for vel, density etc…

I can reference this information is a volume shader, so I get its adding an attribute that can be used.

1. Is this its only function?

2. Can I use these attributes to influence another RBD sim or something, how do you go about that?

3. Can I do similar things with POP nets and use Particle AGE attibutes within shaders etc…?


Sorry so many questions…so many Houdini discoveries still to make!

BTW, I really do appreciate all the help from this forum in learning Houdini - I would be in dark about so many things with it - many thanks!

I've made an attempt to get the velocity from my smoke object to affect some geometry, but for some reason I'm getting an error when I try to merge in the field force.

Maybe it because my source object is a missing something? :?

The problem is that you cannot merge data with objects. In order to apply the field force, you need to wire the rbd object steam into the field force. Also, I recommend you alter the input order of the merge so that the smoke solver is connected last. There was a bug fixed recently where the smoke object wasn't ordered correctly.

Thanks Graham!

That's got things moving, although not how I expected. Is there a guidline as to how big your forces should be compared to the size of your objects?