3 Replies Latest reply on Jun 5, 2016 10:49 PM by trey38647

# Will a 2D circle shape gradually change into an ellipse?

Hi all, let us assume one shot a live action footage plate in their garden, where the scene is the camera looking straight ahead at a tree for example and then the camera operator walks from left to right with the camera still looking ahead. That plate is then brought into AE and the 2D tracker is applied. What if one then creates a solid circle shape in AE as shown by 'A' in the picture below. The question is, as the camera moves from left to right, would that solid cicle shape gradually change from a full circle to an elliptical type shape as shown in 'B'? I ask because if one were to place a Hula hoop (which is circular as we know) on a 4 feet stand and stuck the stand on the ground, if one were to move left or right while looking at the hoop, our vision combined with optical physics changes or bends the shape of the full circle and then transforms the hoop into more of an ellipse/oval.

I just wanted to know if AE will treat the digital 2D circle shape in the same way when footage is brought into AE and 2D camera tracked.

• ###### 1. Re: Will a 2D circle shape gradually change into an ellipse?

Why should it? Pixels are pixels and 2D is 2D. AE doesn't care. Any perception of perspective will have to be achieved using other means like 3D tracking (which of course in your case probably won't work) and using 3D layers or animating the shape. And even then there may be extra work required, since realworld lenses are rarely just simple spherical lenses and distortions are more complex than just scaling on one axis, anyway.

Mylenium

• ###### 2. Re: Will a 2D circle shape gradually change into an ellipse?

You would Camera Track and parent a 3D layer to a null or you would Corner Pin Track and composite that way. These are basics. The answer is yes, you can do composite about anything you have ever seen in a commercial or movie in AE if you use the right procedures.

Not a circle, but for example:

In the future please just drag your sample images into the reply field on this forum. It couldn't be easier and we will spend less time trying to answer your questions.

• ###### 3. Re: Will a 2D circle shape gradually change into an ellipse?

Thank you Mylenium.

Also, thanks again Mr Gerard. Glad for the tip. Sorry about the picture; I selected the picture icon and entered the URL but I think it is better to embed the picture in the actual post the next time.