Pflow: Spin Rate controlled by particle speed

[osukas]

Hello, I'm making a simple particle system where I want the shapes to be spinning in the air and bouncing, but when the particle stops on the floor, I want the spinning to stop.

I found this one how to change the scale of the particle based on the speed, I know nothing about scripting, is possible to do this with the object spinning by particle velocity?

https://www.scriptspot.com/bobo/mxs5/pflow/pflow__particle_Lenght_by_velocity.htm

[Diffus3d · Accepted solution]

Hello @osukas ,

Generally speaking, when you want a PFlow particle behavior to change, it needs to interact with a test node.  (Those yellow nodes shaped like warning signs.)   So if you put a collision test there and a deflector where it will hit the floor, you can drag a new rotation or spin node (however you are causing the spin) into an empty area and make that the target for passing the test by linking it up to the circle input next to the test.  In this case, for a successful deflection.  Any particle that passes the test will then go to the next event which is your override spin/rotation nodes.  

Does that make sense?  Also, you need a display node in that new event as well if you want to see the particles.  

Or, you can use mParticles instead which have certain physics built in by default.  The usage is a little different so I recommend looking up some tutorials, but the same test->new event workflow exists throughout PFlow. 

EDIT:  I mention this because linking particle rotation to speed directly will likely not look realistic and will cause weirdness with motion blur.  If you are heckbent on it, there is a speed space and speed space follow already existing as part of the Spin and Rotation 'spin axis' dropdown.  I believe those can be used for this purpose, but in my experience are finicky.  

Best Regards,

[osukas]

Thanks! Using mParticles particles makes more sense, I'm going to give it a try, luckily the render I was doing has small particles so the spinning is barely noticeable, but I'm going to try it for bigger ones in the future

[Diffus3d]

The mParticles are fun actually.  I did a commercial once with flying coffee beans slowly rotating and they slammed into each other in a pleasing way.  It's pretty great but the birth and initial motion is a bit different.  Best of luck! 

Best Regards,