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View Full Version : Turbulence Field - I cant tell the difference between PhaseX, PhaseY and PhaseZ.


torebjerkan
12-27-2006, 08:41 AM
I've tried to apply the same animation(expressions) on all three phase attributes to see if I there's a difference. According to the help file I'm supposed to see a noise disturbance move along the dimension I've chosen to animate. As far as my keen eye can tell there's no difference between either. For clarity's sake I set up a particle emitter with cycle emission turned on to study more precise how particles travel through a turbulence field. Still, I cannot spot a difference between the phase attributes. It would be nice if somebody could tell me how to set up a scene that would vizualise the difference, or at least give me some pointers. Thanks.

Ge-ZUS
12-28-2006, 06:04 AM
What values did you use for phaseXYZ? Did you use a constant value? Alvarez from gnomon always used an expression depending on frame count ("phaseX = (frame * 5)" or so...). Do you see any difference now?

sunit
12-28-2006, 08:33 AM
the easiest way i find to visualize turbulence is as a noise field - think of it as a 3d noise texture where each pixel represents a velocity rather than just an intensity. as you change a phase value, you're basically translating the noise field along that axis. moving the actual turbulence field transform will also get you a similar effect.

in the same way that actual air turbulence doesn't stay fixed, expressing phase in terms of time means that you've got a moving turbulence field.

a good way to check the effect is to create a particle grid, with the conserve at 0 on the particleShape. set the turbulence magnitude to 10 or so ( turn on attenuation ), and see what happens. this way your particles don't inherit any velocity ( they don't carry momentum ), and you can see what the phase is doing. working with an emitter is difficult because you're already dealing with velocity/direction/speed from the emitter.

-sunit

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