Particle & Deflector newbie desperate for help

[depth3d]

Hi all

I have used Max for a while now but have never had to use the Particle or Deflector part of the animation facilities. I am trying to make a bunch of instanced shapes that are (in reality) already in a tank of water move. I need about 300 of these shapes to be carried to the top of the water by an air stream (air stream already built and working happily, thank goodness) and once at the top of the water the shapes disperse out towards the sides of the tank before sinking slowly to the bottom and being caught again by the air stream to be carried up once more. I need this cycle to repeat in a loop.

I don't know which particle system to use or how to make the shapes travel up and out and down and back up again. Also, I can't seem to make it appear as if they are already in the tank and, try as I might, I cannot seem to apply a udeflector to the tank to prevent the shapes passing through its wall.

I am completely stuck and would welcome any help and guidance you wonderful people might be able to give me.

Very many thanks

Patrick

depth3d

[BenBisares · Accepted solution]

I can certainly help you with that.

Off the top of my head I would do the following:

-Build a deflector representing the top of the water. This deflector would have a bounce of 0 (or close to it) and a high friction.

-Have an event ("Event001") of a wind force blowing the shapes up towards the surface. In addition I would add a drag force to make it behave more like they're underwater.

-I would have a Collision operator that would pass the particles hitting the water surface to another event ("Event002" let's say)

-Event002 will not have the wind force in it but the particles should still inherit the momentum from the previous event.

-This part would be up to you. You would then pass the particles to a 3rd event ("Event003") using, I would say, either a Speed Test or Age Test. Basically once the particles either slow past a certain speed or after a certain amount of time they will be passed to the 3rd event

-Event003 contains a gravity force to bring the particles back down, a drag to slow things down (could be the same one from Event001), and another wind force but this one is set to "Spherical" with a negative strength. This wind will "suck" the particles towards the original wind which will start the process all over again.

Again this is all after about a couple of minutes of thought. It most likely could be refined in some way. I just wanted to give you an idea to play around with. I encourage anyone else to give their 2 cents worth on this one.

    try as I might, I cannot seem to apply a udeflector to the tank to prevent the shapes passing through its wall.

Where is the problem coming from? Can you add the tank as the object source in the UDeflector?

[depth3d]

Ben

I really appreciate your taking the time to help me. I will give those methods a whirl and see how I get along. I have solved the udeflector problem. I used a standard shape from the list available and it suddenly occurred to me that the shape needs to be hollow. I cloned an edited cylinder and scaled it down to .98 boolean subtracting the smaller from the larger, applied the udeflector to the shape and hey presto! no shapes passing through the wall

I will let you know how I fare with your advice.

Again, a thousand thanks.

Kind regards

Patrick

[BenBisares]

My pleasure.

By the way, unless you are using mParticles (2013 with extension, 2014) the particle collision will only be tested against the particle centre not the shape of the particle itself. So for example if your particle is represented by a 1cm diametre sphere. 0.5cm of the sphere will pass through when it collides with a deflector because it's only the centre that collides.

You may want to create an invisible cylinder for your uDeflector that's a bit smaller than your tank (0.5cm in my example above) so you don't get particles that poke through.

[mgrass95]

Would he not want the invisible cylinder to be .5cm larger instead of smaller so that the particles can collide with it and then that .5cm radii would put the surface of the particle right on the surface of the visible and smaller tank?