From: "Chris Zwar" <chris@chriszwar.com>
To: "After Effects Mail List" <AE-List@media-motion.tv>
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Date: Fri, 21 Feb 2014 04:54:36 +0000
Subject: Re:  [AE] 3D ribbon with Particular
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I haven't used cineware but it sounds like you're heading towards headach=
e territory.  What you're wanting to do is z-depth compositing and that's=
 not really easy in After Effects.  Particular has its own 3D world and o=
utputs a 2D image, my guess is that's how cineware works too - there's th=
e chinaware 3D world which is different and separate to the After Effects=
 3D world.  

So basically - you have 3 different 3D worlds and you want to composite t=
hem together.  If your camera is either static or not moving much then yo=
u can do it manually by splitting layers, but if you have a dynamic camer=
a move then it will get too hard, too quickly.  In theory each 3D world c=
ould spit out a z-depth matte and you would use that to composite everyth=
ing together, but that's not simple.  I haven't googled around but there =
are probably a few tutorials around on how to fudge it - I know I tried a=
 setup once using the extract plugin to pull luma mattes - so maybe see w=
hat you can find.

The approach I suggested is a bit of a fudge that is really using particu=
lar as a z-depth compositor.  But that works with only 1 other source, an=
d if you're combining chinaware, after effects and particular then you ha=
ve 2.

(BTW if your camera isn't moving much then it won't be too bad.  I'm thin=
king of a project I worked on which involved a 3D particular ribbon being=
 comped into a city flythrough, which was more involved)

-Chris

-----Original Message-----
From: Teddy Gage [mailto:teddygage@gmail.com]
Sent: Friday, February 21, 2014 02:50 PM
To: 'After Effects Mail List'
Subject: Re: [AE] 3D ribbon with Particular

Nice Chris, I'm gonna try that. Will definitely give sParticular a look a=
s
well. Would there be a way to integrate a 3D element from cineware into 3=
d
AE layers? dealing with hundreds of photos mixed with video is much slowe=
r
in cinema
-TG


On Thu, Feb 20, 2014 at 7:59 PM, Chris Zwar <chris@chriszwar.com> wrote:

> 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 slo=
w)
> or you can use an expression, which is fast and free but a bit of a pai=
n
> and not always 100% perfect (because the corners of a layer are a diffe=
rent
> distance to camera than the centre).
>
> To do it in AE, you need to duplicate your main composition with all yo=
ur
> 3D 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 o=
f
> grey based on the distance to the camera:
>
>
> camp=3DthisComp.layer("Camera 1").toWorld([0,0,0]); // camera position =
//
> lp=3DthisLayer.toWorld(thisLayer.anchorPoint); // layer position //
> d=3Dlength(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 particula=
r as
> the 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=
 the
> images. My first thought was 3D stroke, but it didn't work, as I need i=
t to
> have some shading from the comp lights. There's also the issue of painf=
ully
> 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 dimensi=
ons,
> just postcard transforms on the 2D mask paths, AFAIK.) I may however us=
e it
> for some simple bending and repeating elements.
>
>      My next idea is to use a particular 2.0 layer with 0 emit velocity=
,
> and having the emitter tied to a null that I can then fully animate thr=
ough
> 3D space. So far this is working pretty well. Comp lights work, it is e=
asy
> to control.  However I am having some of the classic issues with Partic=
ular
> where it crosses other 3D objects in the scene and doesn't respect the
> stacking order. The ribbon is either completely in front of or complete=
ly
> behind the images.
>
> - now I could add 1 or 2 "obscuration layers" but it is not reasonable =
to
> do 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 w=
ould
> 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
> Particular maybe?
>
> Thanks,
> -TG
>
>
>
> --
> _____________________________
> VFX & Motion Graphic Artist
> teddygage dot com
>
>
>
> +---End of message---+
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>


-- 
_____________________________
VFX & Motion Graphic Artist
teddygage dot com