Auto-orient layers in Pre-comp Help.

[redwards 0]

Okay here's what I am trying to do in After Effects...

 

I have a grid layout of square layers. I want to have each of these auto-orient individually towards a camera.

But when I pre-comp them it just auto-orients the entire pre-comp of the grid towards the camera.

 

I am trying to hide the fact that these layers a paper-thin by having them always look at the camera.

Is there any work-around, expression, any thing to get it to work?

 

Auto-orient works fine before I pre-comp but I would ideally want to pre-comp the grid because it consists of a lot of squares.

 

Thanks in advance for reading/your help.

 

-Ryan

[thomwill 0]

you should just have to collapse your pre-comp.

[kitkats 0]

No, that doesn't work. The auto-orient property only applies to cameras in the comp the layer it is applied to is in.

 

What you need to do is this. Make a new camera in the precomp, and 'parent' it to the camera in your main comp via an expression for position with something like:

 

comp("Main Comp").layer("Camera 1").transform.position

 

If you like to use the expression pickwhip, you can temporarily pull one of the comps out of the timeline and have two timelines, one on top of the other, then pickwhip from one comp to the other.

 

Setting up a Master Cam like this can be useful in other ways depending on your workflow. If you want to flatten several copies of a 3D scene and layer them up with transfer modes, you can achieve stacks this way not possible with adjustment layers.

Edited October 19, 2007 by Steven Kirby

[YKo 0]

good stuff

thanks

[basilisk 0]

this reminds me of a similar technique to make Trapcode Particular particles individually to respond to camera movement (in this case to prevent them auto-aligning to the camera) by nesting a camera in a precomp and linking it to the main camera. Graymachine did a great tute on this

 

(edited for American English spelling of grey)

Edited October 19, 2007 by basilisk

[graymachine 0]

this reminds me of a similar technique to make Trapcode Particular particles individually to respond to camera movement (in this case to prevent them auto-aligning to the camera) by nesting a camera in a precomp and linking it to the main camera. Greymachine did a great tute on this

 

This reminds me, I need to fix the shortcoming on this where distance is applied to the particles twice.

 

But yeah, this tut would be a good reference for what you are trying to achieve. I use this on occasion when I 'd like to precompose Invigorator elements in a scene, and still follow the camera in the main comp.

[redwards 0]

Thank you so much, I really appreciate all the feedback.

[spritelyjim 0]

Harry, I sent you a fix for the auto-orienting particle scaling, but you may not have seen it. Or you don't want to rip someone elses solution. I would understand that. Anyway, for everyone else, this is the email I sent graymachine:

 

Well, I finally posted the inquiry at the Cow, but with an extremely

simplified example. Colin Braley gave me the following expression that

I'm using to link the camera's position in the particle comp to the

camera in the main comp. The dist parameter maintains a fixed distance

from the particle camera's point-of-interest, which works great. I've

been able to use it to make particles from 2.5D setups, CC cylinder,

shatter, and even another instance of particular. Hope this helps!

 

Jim

 

 

cameraPoi = thisComp.layer("Main Cam").transform.pointOfInterest;

cameraPos = thisComp.layer("Main Cam").transform.position;

dist = 100;//distance from point of interest

//--

vec = normalize( cameraPos - cameraPoi );

vec * dist + cameraPoi

 

just pick whip cameraPoi to the camera's point of interest, and

cameraPos to the camera's position. Change distance to change the

layer's distance away from the point of interest.