# How to set the direction of particle?

Good day everyone.
In Harmony 10 I’m trying to create a system particle depicting flying clouds during the flight of the aircraft. But I could not figure out which parameter is responsible for the direction of motion of the particles, so that they were moving away from the camera.
As an example, we can consider the speed-lines from the standard library. But again, I do not understand how to invert the direction of their movement.

Are you referring to weather clouds passed by as the aircraft moves through the sky or clouds of engine blast emitted from the aircraft?

There is also the Integrated Help Window available off the Network Window menu (down arrow/+ button) that explains the functions of each module component. Directional control will be within one of the purple modules. The specific module will depend on which of the two scenarios you are aiming to create.

This.
I tried to set the direction through Z in velocity, but the clouds spiraling, losing the top and bottom.

Are you going to attach a Peg to the clouds to participate in the illusion?

And what will happen? Just before I did not use pegs for particles

Animating a Peg attached to the particle system would allow you to animate the position of the particle activity in the scene.

Just as the plane might fly from one side to the other the clouds would move in the opposite direction facilitating the illusion.

Which modules do have you in mind to use for this effect?

A Peg may not have any influence depending on how you approach this.

something like this (if I understand you correctly)
http://images.gameru.net/image/direct/3ace9865a2.png

There is more than one way to direct particles, but one that’s easy to remember is applying a gravity effect node and setting the direction to what you need. Since clouds don’t need to drop like a canon ball, this would work easy enough. Don’t forget to play with the mass settings in your particle emitter. Things like that might affect what you’re trying to do.

What are you aiming to accomplish by using particles instead of flat cartoon clouds?

I finally figured out the direction of motion of the particles, but got more questions:

1. large and variable speed generated particles.
2. The particles are always on top of imported 3D models.

To make it clearer what I mean, I attaching a link to a file.

chanyuan0811