Creating foot down state and using it for emission

[starlighter]

Hi all!

I am a fairly new user of Houdini, and was wondering if anyone can help me out or point me into a good direction on how to create a foot down state, or anything similar to that, that i can use further down as an emission for particles or just creating simple geo.

In case i didn't explain well above, i'll give you an example. I have a horse running across the field and i need to emit/generate content only on the first contact when the hoofs touch the ground and not through the entire time when they are touching it.

Many thanks for any help.

Cheers!

[Atom]

One way is to use an attribute transfer to transfer color from one surface to another when they are close, such as footprints. The result is you will have a bright color on the ground only at the places where the foot once touched. Then you can delete non-bright points and supply those remaining bright points to a particle system for emission.

Check out this video for more details or download the example files.

https://www.sidefx.com/tutorials/geometry-solver-footprints/

 

Edited July 21, 2017 by Atom

[starlighter]

Hey Atom, thanks a lot for your reply. Yes, i did check that tutorial, but somehow still haven't managed to adapt it to my needs. Not sure if i misunderstood you, but in my case i need to emit particles only on the first frame of the contact between the foot/hoof and the ground, and for the next 4-5 frames when there is a contact i don't need any emission.

I'll go again through your post however, maybe i missed something.

Thanks!

[Atom]

Here is an example file mixing two techniques. The footprints solver from the video mentioned above and the tire spray particles from this link.

 

footprints_solver.zip