Basic nParticle rotationPP?

#1

Here is a video link of me failing to solve the problem:
//youtu.be/1JgbEk2oY70

I am trying to get instanced nParticles to rotate using themenu options and without expressions. There are a number of video tutorials that
show how this is easy to do. I have followed these examples and yet my
particles will not rotate. This video documents the process I followed which
was unsuccessful. Please let me know what step I am missing. Under nParticle
shape options I checked compute rotations and then another nParticle shape
options under instancer/ rotation options I chose rotationPP. I get no rotation
to my nParticles.

#2

From the docs:
If the particle has collisions or uses the liquid solver then compute rotations per particle.

Do your particles collide or use the liquid solver?

#3

I have tried it with nParticle collision on and off. Liquid solver is not on. I followed a number of video tutorials that made it successfully work and it appears they did not use liquid solver. Here is an example of one of the videos I followed.

//youtu.be/LiUup6HDVKg

#4

What I tried to say is: Do your particles collide? In the video do not seem to collide with anything. No collision, no rotation. The automatic rotation only works if a particle hits something so that the rotation can be calculated from the collision angle. If you simply emit particles, the particle system does not know how to roatate particles.

#5

Yes, to need to define an initial rotation speed if you want them to start rotating. The following creation expression should do the trick:
nParticleShape1.angularVelocityPP =<<rand(0.5),rand(0.5),rand(0.5)>>;

(change 0.5 to larger values if you want faster rotation)

Also in the create expression you could also use a similar expression to set the rotationPP if you want that to start at a random value:
nParticleShape1.rotationPP =<<rand(360),rand(360),rand(360)>>;

#6

You are the principal scientist for autodesk ? Wow! Thanks for taking the time to answer my question. Your solution completely worked.