Maxwell Render can render in Deep image format, which stores not just color but also depth information per pixel, making it much easier to composite rendered objects together as well as eliminating troublesome edge artifacts. 

The image formats that support Deep information are .Exr and .DTex, and both are supported by Maxwell. 

You can save all the RGBA channels with Deep information or just the Alpha channel. 

• Minimum distance (m): closer distance to the camera for taking the first depth sample. 
• Maximum samples: number of depth information samples stored per pixel.