Ola Madsen with a post looking at creating HDR environment maps from a 3D scene, showing a technique for creating a custom IBL using a chrome ball, in this case using Softimage. This is most likely transferable to other applications however, with nothing that couldn’t be done in Maya, Cinema 4D, etc. without too much trouble.
Generating a HDR environment from your 3d scene is in fact not that much different from how you would go about in real life
Ola notes that there are essentially two ways to create an HDR environment in real life, siting the chrome ball and the multiple stitched images creating a panorama. In creating them in 3D, some third party renderers will also allow you to have a lens shader that will distort the image which can also be used to create a lat-long image for HDR IBLs.
Check out the post for Creating HDR Environment Maps from a 3D Scene Using Softimage here.
