I am using Carrara 1.1 and I am trying to set up an animation of a projector projecting a movie onto a screen. I got the models for the projector and the projection screen off of the included resource disc. I then placed a spot light just in front of the projector pointing at the screen.
The first problem I had was the shape of the light being circular. I have solved that by creating a square mask and applying that to the spot. I then thought it would look best if there was some faint volumetric light coming from the projector so I added that as well. The problem I am having is that the volume lighting does not interact with the screen. It just goes on through the screen. I need it to stop at the screen. I cannot figure out how to make the lighting stop at the screen. Is there a way to adjust the length of the light? I have been looking through the maanual and the various options on the light and cannot seem to figure it out.
Is there a better way to do what I am trying to do? Is there a way to have the light actually project the movie clip or do I need to just apply the clip to the screen as a material?
Any help would be appreciated.
Thanks.

You can have the light project the clip by putting the .avi or .mov or whatever as a gel for the spot light. And you mean the light cone keeps going through the screen? If this is the case, enable 3D Shadows in the light cone properties and the light cone will stop when it hits objects.

I will give those a try when I get home. Thank you so much.

You need to turn on the shadows check box for the light cone. -Kix

Thanks. That fixed the light passing through the screen problem. I used the movie as a gel and it is projecting it onto the screen. The problem I have now is that it projects it in a circular shape on the screen. Can the shape of a spot light be change. I need it to project in the shape of the screen which would be rectangular. I had previously been using a map of a black rectangle with a white rectangle as a gel which made the spot light project as a rectangle. How can I project the movie through the spot and have it rectangular at the same time?

You can't change the shape but here's two possibilities. 1.) You could move the light source slightly inside the projector and project it through a square opening (just like the real thing). The opening would cast the square shadow and give you a square result. Turn on the soft shadows if you have the rendering time too. 2.) You can also have an object cast a shadow without it being visible. A square opening would again do the trick. Just two thoughts. -Kix

Those are great ideas. I will give those a try. Thanks.