Particular – aiming

[Mike Park]

When I need precise control over particular, I usually create a null object for the particular source and a null object for the target. I then picwip the rotational values of the particular emitter to the source null rotation. (make sure the source null and the particular emitter occupy the same space) Next, I use the lookat function to make the source null always rotate toward the target null in 3d space. Then, just position the target null anywhere you want and the particle emitter will shoot towards the target.

Hope this helps.

[Roland R. kahlenberg]

Mark has a few good pointers for particles to follow a motion path. But for something like what you’re looking for, I’ll likely look at using Trapcode Particular’s Air>Wind properties.

HTH
RoRK

broadcastGEMs – AEPro Volume 02 (Professional Adobe After Effects Project Files – Now Available).

Adobe After Effects Training in South East Asia.

[Mike Park]

John,

What version of particular and After Effects are you using. I currently have CS4 installed on this machine with the latest version of Particular, 1.5.1. If you have these, I will send you a project file with the emitter all linked up. All you have to do is move the target null anywhere in 3d space and the particular emitter will automatically orient toward the target null. Positive values in z space go back, negative values of the target null in z space come towards you out of the screen. Just give me your email, and I will send it your way.

Mike

[Mike Park]

In response to Roland’s post, you could use the wind paramaters to control direction. However, in order to get a straight line, you would have to have the velocity of the particles start at 0 and then the wind would accelerate the particles in the direction you wanted. This will require some trial and error and won’t be super precise. Also, it does not allow the particles to have any initial velocity, unless you correctly orient the particles in the direction of the wind, which defeats the purpose of your original post.

If you really dont want to use expressions and picwip, you could cheat and create a camera in the scene, create a 3d null, parent the camera to the null and use the null’s rotation to control the relative direction of the particles. Obviously, this only works if you are not using any other cameras in the scene. If so, you will have to precompose the Particular solid layer with the orientation camera…and that can get messy if you need to make many adjustments or the main camera in your scene changes. I like the expression method the best.

Mike

[John Hammond]

Hi Mike,

I have CS3 and Particular 1.5.0,

That would be great if you could send me the file, may not work but I can try it anyway.

If not, I think I can re make it from your earlier description -I am confident with the pickwhip and simple expressions. The only thing I’m unsure about is the ‘lookat function’. Is that an expression, or a button I don’t know about? If it’s an expression I think I have Dan Ebberts’ version saved on my machine which I could pilfer.

Roland – thanks, I will play with the Air/Wind options, But it’s the aiming I have real trouble with. It may work fine for this project actually, but I think Mike’s set up would be a good thing for me to have in my arsenal.

My email: burnt.toast AT ntlworld DOT com

Thanks for all the help
John

[Michael Szalapski]

You can also use an AE light as the emitter for your particles. The direction, cone width and all that stuff controls the particle emitter.

– The Great Szalam
(The ‘Great’ stands for ‘Not So Great, in fact, Extremely Humble’)

No trees were harmed in the creation of this message, but several thousand electrons were mildly inconvenienced.

[Kevin Camp]

yep, using a spot light as an emitter (just name it ’emitter’) may be the easiest way to go.

you’d then point the emitter by manipulating the light’s point of interest. to make that a bit easier you can use the expression pickwhip to link the poi to a 3d null and then manipulate the null.

Kevin Camp
Senior Designer
KCPQ, KMYQ & KRCW

[John Hammond]

I had never spotted the option to use a light as an emitter – that’s awsome