[ANSWERED] Make a sand tampest with Small particles without trace

[tease]

Hello,

I'm trying to simulate a sand tampest with 3d particule for a stage effect.

My probleme is that when particule take speed they elongate a lot, and do not look like sand anymore!

When I do print screen to demonstrate this effet, the particles are not elongate. So i could be my eye that makes this or the screen...

Does somebody have an idea how to limite this effect?

I've attached the patch : sand tempest.izz

Thanks, and happy holidays to all!!!

[bonemap]

@tease

Hi, 

From my limited experience using the 3D Particles actor in Isadora, I would say, just looking at the parameters for the particles life span (fade-in, hold, fade-out), that you might try a much shorter duration. This will cause the individual particles to be generated and fade-out more frequently and therefore reduce the effect in the human eye known as ‘persistence of vision’. Making the ‘time’ parameters in fractions of seconds will most likely create a strobe effect that will reduce the perception of ‘trace’ that I would associate with a visual tail created in the eye when the particle is animated through virtual space. A 6 - 9 second lifespan, as indicated in your screen grab, is going to provide a lot of time for a visual trail to persist - so reducing these parameters to simulate a strobe effect might work to your aesthetic when animating particles.

You can also look at using a formula to optimise the processing of your particle system. For example, there is going to be a relationship between the frequency that a particle is added, the duration of each particle and the maximum number of particles. A calculation based on a particle system that has an 'add' frequency of 166 hz, theoretically will add 166 particles each second. However, if I want these particles to have a life span of 15 frames (equivalent of 0.5 sec at 30 FPS) then the maximum number of current active particles generated will be only 83 per second (166 x 0.5 = 83). But, 15 frames is still going to have the potential to produce a visible tail (a 15 frame trace) that will give the perception of an elongated particle if the particle is animated, for example using gravity properties.

Another option is to NOT apply any properties that will animate the particle and therefore not produce a tail. If you are creating new particles based on only moving the x,y 'add' parameters, then the particle can persist without moving in any coordinate direction and therefore, it can not produce a trace or tail. using this technique you can increase the number of particles based on the capacity of cycles available to Isadora. If you use a 'Pulse Generator' consider that the maximum number of trigger pulses possible is approximately equivalent to the maximum cycle rate of your computer hardware. I would be happy to hear some different views on this.

I have played around a little with these concepts in the attached patch v3.0.7.

Particle-strobe.izz

[tease]

Hello Bonemap,

Thank you for your input, its interesting to follow your string of thoughts! 

You are pointing my problem and dillema: I need to have an illusion of mouvement for the tempest, so maybe a little trail is necessary, but can't have long sand graines!

I'll play with the parameters you are suggesting, 

Thanks a lot!!!