This script converts a panoramic image into a 3D cylinder that can be used as a background in a 3D composition. Requires After Effects CS3 or later.Download pt_Panorama from aescripts.com
The full help is included with the script, but here are the basics:
1. Drop a panoramic image into your comp and select it.
2. Launch pt_Panorama and review the options. Choose whether to create a full or partial cylinder (60-360 degrees), the number of sides and whether the sides overlap (prevents gaps when using motion blur).
3. Click Apply and the 3D panorama will be generated and precomposed. The layer is scaled to 20000% in order to simulate a distant background, which means you should be able to freely fly the camera around without ever hitting the sides.