Data operator: How to read the angle of the normals

#1

Hi, I’m working on a rain system simulation with particle flow. I have my particles travelling down on the surface of my object with a “lock and bond” operator and I would like to send my particles to another event when they reach the limits of the geometry or when they reach a polygon facing down, so the particles can leave the object and fall down to the ground by gravity force.

I though that one method would be get the angle of the normals with a data operator and if they are pointing to the ground, use this to drive the particle behavior. I’m stuck at this point because I don’t know how to get this data… any help would be really apreciated.

I thought of other method by using a manually painted texture, but I would like to automatize the process.

Thanks! :slight_smile:

#2

Should be easy enough, you can read the point normal of the object and the position of the particle on that normal, then set a condition against the latitude of the normal of the current position, any negative number should have a downward facing normal.

See attached example:
https://www.dropbox.com/s/yi8qep7tggktfhf/max2016_PF_DownwardPointNormal.zip?dl=0

#3

Thanks JohnnyRandom, it works perfect! I need to keep learning all the data operators details. I can finally continue developing the simulation, your example file was a great help :slight_smile:

Many thanks again!!!

#4

No worries, glad to help :slight_smile: