Hi,
I have a car + exhaust pipe and smoke particles.
Particles have constant velocity x = - 4.

Particles matrix = actor.matrix();

But if i'm driving my car - particles direction is still the same, why?

What should i do to achieve the desired effect ?

Try add this under exhaust_particle->matrix:

exhaust_particle->vel_constant=actor.matrix().angles();

No, no effect.

I think particle->matrix = actor.matrix should be enough.... but it doesn't work.
:(

In my problem it worked as I want.

What was your problem ? Write about... maybe this will help...

You said : exhaust_particle->vel_constant = actor.matrix().angles();
But i don't want change vel_constant :/ vel_constant it's defined in my particle file and its only (X: -4)

I wanted make some dirt under wheels. And it's always behind car when I put this line. It isn't exactly the same situation as yours but I hoped that it help you.

vel_constant tells what direction it should point at - it takes in a vector

(02-21-2011 12:22 AM)Harry Wrote:  I wanted make some dirt under wheels. And it's always behind car when I put this line. It isn't exactly the same situation as yours but I hoped that it help you.

Just you got lucky ;]

if you put it vel_constant = -4 you're actually putting vel_constant = (-4,-4,-4) so try harrys solution.

also, exhaust_particle->matrix = actor.matrix(); just says that the particle is in the same position as the actor; it doesn't tell the particle what direction it should shoot at.

I think you put vel_constant as -4 because of its ambiguous name. To change the particles actual "velocity", i think you would use exhaust_particle->accel->set(x,y,z);

I don't need change vel_const... my smoke particle it's defined in Model Editor -> Particle and vel_cons (X= -4)

Problem is if i'm rotating my car, particle matrix is still the same, smoke direction is always the same.. :(

Look at screenshot

sorry, i edited my post. reread it

edit : ah, you said velocity x = - 4... misread, but try harrys solution anyways it should work

If you move the particles position it will effect the smoke particle as well... so the constant velocity is not needed at all what you guys want to believe... try it as test in the editor and move the particle

OK, maybe this example shows you my problem better.

I have some Dragster with two turbojet engines - engines spits flames (flames is a particle with cons_vel Z = 5.

update---------
{
flames_particle.matrix = dragster.actor.matrix();
}
update---------

If car goes up then flames is ok (because cons_vel Z = 5), but if dragster goes down then flames still the same direction?

What I should do to properly set flame ?

If you don't use the constant vel, like i said in my other post, how does it look like?

So the constant vel is the same as moving the particle itself.. depends on how fast you go of course but thats just tweaking with the amount of particles.

Right now the direction of the smoke is going, lets say, down, but you want it to be relative to the actor and not the world.

By having vel_constant to be a constant number (z=5), it will always point in that direction relative to the world ( it will not pay any attention to the direction of the car, as shown in your diagram ).

Since you want the smoke to shoot away from the direction of the car, you would use directions relative to IT ( it will not pay any attention to its direction in the world - which is what we want ).


not done reply..