Hey all!

So I'm teaching myself houdini and I've reached a bit of an impasse. I used Digital Tutors and the great Peter Quint but the issue that keeps screwing me over is in regards to how Houdini 14's particle work flow is different to the old ones.

All the tutorials are based around houdini 9 and they way they set up particles is naturally different to how we are meant to do it now.

My main issue is this; say I use the shelf tab particles from location and then i place a grid. If I then want to use a collision detect node so that the particles will bounce off the grid, I set it up but the particles NEVER react. I even change the grid to a static object and nothing comes of it. I mess around with all the settings and I can't get it to work. I've attached a file showing an example.

if I then try and follow their workflow by using the old popnet node when it comes to collision time i get the error no particle system exists please make a particle system.

It's driving me up the wall. I feel I can't learn loads of tutorials because I'm unable to follow them with houdini 14.

I'm new so am I just being dumb? Is there something I'm missing? Hell I went to quickly make rain following a sidefx word doc tutorial and that too was using the old workflow despite it saying how to do it in houdini 14.

Any help or explanation would be much appreciated. You can treat me like a five year old if it helps!

Thanks for taking the time to help!

Okay so after slogging through this forum I found the answer that rather than making my grid or object static, I should have use the Terrain SOP.

Now my question is, why is it that terrain generates a bouncing effect from the particles when static doesn't?

When you created the static object for the grid, the default collision uses “Volume” and “Ray Intersect”. The problem is that the “Ray Intersect” won't be able to create a volume for a grid. It needs something with an actual volume, like a box. If you change the mode to “Implicit Plane”, then the collision detection would collide with the (infinitely large) plane. Take a look at the attached hip file.