Hey folks, I'm new into Houdini, coming from Maya and Softimage.

I emit few particles, that emits trailing particles. I made two popnets to make it, and it works OK. However, when I add a ground plane, the ground planes are filled with particles from the second popnet (trailing particles). How can I exclude the ground plane from particle emitting?

The first popnet emit particles from a location (pop Location) and the second emits from the previously emitted particles. The ground plane is connected to the second popnet, so I have no clue, how it works

Thanks for all help


Szabolcs

In the first DOP Network, under the “Object Merge” tab, you can specify which objects gets outputted. The default is set to *, which outputs all the objects from inside the DOP Network. This includes the ground plane as well. So the ground plan is being inputted into the next DOP Network. You could see this by setting the display flag on the first DOP Network. If you only want the particles, you could set the “Object” to what your POP object name is, like popobject1.

Also, instead of using two DOP Network, you could try putting both POP solvers into the same DOP Network. Then, you can use POP Source on the second POP solver to get the particles from the first POP object. See the attached .hip file for an example.

Thank you very much Andrew! Now it's OK, and quite clear how it works

And one more question. What is the best way to create smoke trails? I'm trying to use the Copy node with the Cloud object, is it OK?

Depends on what your target medium and what your visual goal is. Whatever you can make work for you is fine.


https://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=42673&highlight=deadline [sidefx.com]
This seems something similar to what you describe, but that guy apparently has some kind of jitter problem at render time. I don't know why.