How to create null objects?

[steeleb]

Hi,

I need to integrate an After Effects 5.5 layer with a 3D animation. I know how to import the Camera data through the *.ma file. But the problem is that when I import the Maya camera into AE I get completely lost and I am not able detect the right position of the 2D layer inside the 3D composition.

So. There is a video on the Adobe site explaining that there should be null objects inside the maya composition. These object should be placed at the position where exactly the 2D layer will come inside AE so we will not get lost. Could some please explain me how to create a null object?

thanks.

the video url: http://www.adobe.com/products/aftereffects/newfeatures.html

on the left.

[steeleb]

Please help. I need to learn this...

I am sure it is something simple. I have tried the maya help. But... I guess "null objects" are not called "null" in maya... because when I search for "null objects" inside the help... I do not get usefull things...

thanks.

[hnf]

simply create a locator. it has no shape and will not be rendered, so it's a null.

[steeleb]

I have tried the locator... but AE will not accept it as a null... what is wrong? I mean... when I import the *.ma file I get the correct camera motion... but in the composition there is only the camera... there should be maya null objects... so that I can replace them with AE layers... and not get lost in the AE X,Y,Z space...

any ideas?

[hnf]

i don't know exactly what you're trying to do. do you need the camera motion in AE ? do you wanna use the camera motion to place things into a 3D composite ??

as far as i can think about a null in maya it should be a locator, because everything else would be rendered within the image. maybe AE delivers a plugin for maya with a special null object ?

[steeleb]

ok... the thing that I want to do is done exactly as it should be done at the video that is located at the link I have posted in the first post. But... again... here is what I want to do:

think about a MAYA project. very simple one. there are two cubes located slightly faraway from each other. The camera flies from left to right looking exactly in the center between those cubes. At this point I want to put a 2D layer right between those cubes in After Effects... this maybe a text for example. I get the *.ma file ready and import it in After Effects... so I got the maya camera into After Effects. The camera flies just as it flies in the MAYA project. But when I want to put my new 2D layer between the cubes (the cube sequence is rendered and placed as a layer in After Effects) I do not know what are the correct coordinates... so my 2D layer gets behind the cubes... or infomt of them... or just not at the position I want it to be. At this point I need a "null object" that will be imported into After Effects with the camera... and that null object is between the two cubes in the Maya file and is representing the location of my 2D layer... that I want to put in AE. So when I import the *.ma file I should get the camera... and a null object that represents the location of my 2D layer... but I could not get this.

I know that no plugins are needed. After Effects 5.5 just gets the basic camera information and null objects form maya ASCII files... with baked keyframe.

so any help now?
...I really need learn how to do this.

thanks.

[sumo-kun]

Ok, here's what those fat cats in California don't want you to know...
It turns out that you must name the locators that you want translated to AE with the word 'null' in the objects e.g.

null_locator1

Also remember to bake your animation data (select the object and bake is a menu option found in the graph editor).
I also noticed that is there are any extra keys, you get an error regarding number of keys. you must bake all keys and have no gaps. It also seems to choke when you try to do long animations (I was unable to do 1200 frames, but I was ok at 300)

A real limitation is that you cannot use these nulls for the corner pin effect, much less things like lighting, flo motion, etc. From my initial investigation the expression language lets you get a worldspace from an object, so perhaps therin lies the solution, I will post an expression when I get it working. As glad as I am to see the expressions in AE, I have to say that they suck, and they better get it together (along with their keyframe editor) before Apple releases iComposite
-MD

[steeleb]

great... your help is just so valuable for me!!! I spent hours and hours working and trying to figure out the solution... then got stuck and tried the align the 3D sequence with the 2D layer moving it pixel by pixel in the XYZ space... and ended up completely lost...

so I have not tried your way yet... I just got so excited and wanted to thank you first for the great help. Here I will test it now and see if it works...

thanks alot MD...