nParticles: Goals UVs Distribution


#1

Hi,

Couldn’t find any easy/working method around the internet hopefully I could get an answer now.

I have several nParticle emitters which has one goal object.

Problem is all particles goes to specific vertices, while all the rest of the object left uncover…

I know there’s a way to play with goal UVs but couldn’t figure it out…

PLEASE HELP.


#2

Hi,

by default goaled particles will aim for the vertices. On the nParticle in the “Add Dynamic Attributes” tab > “General” > “Particle” add the attributes “goalU” and “goalV”. Now you need a creation expression on these attributes to give randomness to it:

nParticleShape1.goalU = rand(0,1); nParticleShape1.goalV = rand(0,1);

This depends on your UV layout. You may run into problems with overlapping UVs or poor layouts.

Regards


#3

Thanks for the reply!

I’ve tried that before but the particles stuck when they go.

I’ve created a “0” text letter filled it with nParticles and set initial state. then when applying the goal with expression UV, the O particles make 1 step as an O shape and stop moving…

Any ideas?


#4

Hi,

As a workaround I just extracted the goals object to several geometries and set each to every goal.

Thanks


#5

Hi,

the reason is, that creation expressions won’t work on existing particles. You may try to assign the goalU and goalV in the runtime before dynamics:

if(frame < 2){
goalU = rand(0,1);
goalV = rand(0,1);
}

Regards


#6

Interesting. But when I’m adding the goal U,V attributes it’s already stops emitting, so where and how do I add the script exactly?

Thanks!


#7

Hi.

Does the particle count increase? Maybe the particles move within two frames from the emitter to the goal target.

Regards


#8

Yes, it does on its way to the goal, but then stop after 1 step of calculations. No increasing particles because I set the rate to 0 after applying initial state.

Thanks.


#9

HI.

how to do goal Specify polygon UV positions