Interactive Falling tool || Houdini Tutorial

This video will show how to make a python tool that spawns rocks and let them fall down. It can be a fun and fast way to create scenes with a lot of debris and destruction. In the video I will start from scratch so you can follow along, I do recommend that you have a good understanding of Houdini before following the video.

This tool was made during the Houly challenge and took around 2 hours to build. It was a real fun tool to make and has a lot of potential. The tool is more a prototype of an idea, this shows how to make interactive tools with Houdini.

If you want to challenge yourself this can be a cool tool to keep improving on. Like adding more debris details, better collision detection, more interactive options,.....

More resources for Python states

[NGee]

So awesome, thanks Simon - I've been trying to figure out how to track a start frame for a python state tool and this is very helpful.

[hitman]

Thanks Simon for sharing this tutorial!

[DimiShimi]

Have you found a way to make it independent of the timeline? - I can think of a way to reset the timeline with python when it reaches the end and then do a bit of math and additional parameter to keep track of the offset, but that just does not seem very elegant.

[speculart]

The add point python state does not work for me in 18.5.351. Following your exact steps.

[PeterJansen]

Damn that's cool. Time to learn Hython apparently.

[artmeld]

Very good video, thank you.
Do you know if this kind of hda could be used with Houdini Engine in Unity?

[junzheshen]

I am using Houdini 17.5 and I did not find the "Interactive Tab"

[ReinaldoFuregato]

Nice! I've never ventured into the python interactive so far. It looks very nice and very .. hummm... interactive!
One question: I don't get the need of the "for each loop". Can't you just use the "w" attribute on the wrangler or does this has anything to do with the python way of working? (I only use VEX)