universal style logo question

I’m trying to create the old text orbiting a sphere, but I want it to appear and disappear from behind the sphere. I am able to get the result I want by compositing an half the image without the text to block out the part I don’t want, but I need to do other things in the animation that make this technique difficult.
Can anyone think of how to do this in blender? Maybe a way to make the text squeeze down to hide behind the sphere? The text is actually a single object converted from an SVG, so I can’t easily hide a letter at a time or something like that.
Here’s a test I did with the manually composited part to hide the end of the text as it comes around on the right the second time.
http://bareflix.com/inaura.gif

A quick and drity way of solving that problem would be to keyframe the location of the text so in 1 frame it pops behind the sphere to start the rotation. Add a shape key or two to crush the text down so it hides behind the sphere at the beginning and end of the animation. Keyframe the location again at the end so it pops somewhere out of frame.

I am not sure why using a compositing method is not a good option? If you set it up correctly, you wont have to do much manual rotoscoping at all. The alpha channels of each layer will take care of most of that.

Here is a technique using the shrinkwrap modifier and a plane to hide the text. You could also animate the layer the text is on, so after a the text reaches a certain point you can animate it to move to a layer that is not being rendered or displayed.

Attachments

shrinkwrap_text_reveal.blend (138 KB)

That’s perfect, though I don’t really understand why it works the way it does. How did you figure that out?

The reason I don’t want to use compositing is because I’m doing this for a client who is likely to want text and timing changes, so I don’t want to have a manual step after every change if I can avoid it.

http://wiki.blender.org/index.php/User:Jaguarandi/SummerOfCode2008/ShrinkwrapModifier

The concept is that you are projecting the text to a plane. If you notice, all the vertices of the font object actually do end up projected on to the plane. It is the nature of the projection type, if you change the shrinkwrap type, the modifier behaves differently.

You will want to keep the plane and the curvecircle on a non-renderable layer.

I am attaching another example of shrinkwrap that uses and alternate shrinkwrap type. In this case, the “eyes” are projected long the surface of the sphere.