From: Michael Powers <MPowers@cramer.com>
To: After Effects Mail List <AE-List@media-motion.tv>
Subject: RE: [AE] 3D ribbon with Particular
Thread-Topic: [AE] 3D ribbon with Particular
Thread-Index: AQHPLqA6aDXQh/G1pUWh98201UH9TJq/yh+w
Date: Fri, 21 Feb 2014 14:46:41 +0000
Message-ID: <8C6FE228180FE143B942B993AE2E1C74A85D528A@EXCHANGEMBX.cramerdom.com>
References: <list-5385503@media-motion.tv>
In-Reply-To: <list-5385503@media-motion.tv>
Accept-Language: en-US
Content-Language: en-US
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0

Nice Share.

-----Original Message-----
From: After Effects Mail List [mailto:AE-List@media-motion.tv] On Behalf Of=
 Chris Zwar
Sent: Thursday, February 20, 2014 8:00 PM
To: After Effects Mail List
Subject: Re: [AE] 3D ribbon with Particular

Forget the obscuration layer, you need to create and use a Z depth map.  I =
do this a fair bit with particular within AE.

There are 2 ways - you can buy a plugin (which is accurate but very slow) o=
r you can use an expression, which is fast and free but a bit of a pain and=
 not always 100% perfect (because the corners of a layer are a different di=
stance to camera than the centre).

To do it in AE, you need to duplicate your main composition with all your 3=
D layers and make a Z-depth version.  Strip out everything that isn't a 3D =
layer and isn't going to interact with the ribbon.  Add the fill effect to =
each layer, apply an expression to the colour to fill it with a shade of gr=
ey based on the distance to the camera:


camp=3DthisComp.layer("Camera 1").toWorld([0,0,0]); // camera position // l=
p=3DthisLayer.toWorld(thisLayer.anchorPoint); // layer position // d=3Dleng=
th(camp,lp); // distance from camera to layer //

min=3D0; // this this number for white in particular // max=3D20000; // use=
 this number for black in particular //

v=3Dlinear(d,min,max,1,0); // convert distance to value 0 - 1 //

[v,v,v,1]


To keep things speedy I would pre-render the z depth map, import it and use=
 it with particular -use the same camera distance value in particular as th=
e min and max values in the expression.


-Chris
-----Original Message-----
From: Teddy Gage [mailto:teddygage@gmail.com]
Sent: Friday, February 21, 2014 10:58 AM
To: 'After Effects Mail List'
Subject: [AE] 3D ribbon with Particular

     So I am working for a fashion brand asking for a 3D ribbon effect that=
 twists through fields of photos and video, going in front of and behind th=
e images. My first thought was 3D stroke, but it didn't work, as I need it =
to have some shading from the comp lights. There's also the issue of painfu=
lly retiming the stroke moves using percentages of completion, and not actu=
ally having full "3D" control. (I can't draw a path that goes in all dimens=
ions, just postcard transforms on the 2D mask paths, AFAIK.) I may however =
use it for some simple bending and repeating elements.

     My next idea is to use a particular 2.0 layer with 0 emit velocity, an=
d having the emitter tied to a null that I can then fully animate through 3=
D space. So far this is working pretty well. Comp lights work, it is easy t=
o control.  However I am having some of the classic issues with Particular =
where it crosses other 3D objects in the scene and doesn't respect the stac=
king order. The ribbon is either completely in front of or completely behin=
d the images.

- now I could add 1 or 2 "obscuration layers" but it is not reasonable to d=
o this for over a hundred layers individually

- Would I need to precomp the entire layout, collapse transformations, and =
THEN use the precomp as an obscuring layer? Is this even possible? It would=
 be a difficult way to work, I'd need to have every element layed out in 3D=
 first. Doable, but I'd prefer to create both at once.

- is there another solution I'm not thinking of? A good script for Particul=
ar maybe?

Thanks,
-TG


--
_____________________________
VFX & Motion Graphic Artist
teddygage dot com


+---End of message---+
To unsubscribe send any message to <ae-list-off@media-motion.tv>