Luis Miguel Mora shows how to render semi-transparent materials when using Maxwell Renderer in both 3Ds Max and Autodesk Maya.

MaxwellRender don’t have the phisical possibility to render invisible objects, but we can play with the Opacity channel in the maxwell materials to achieve the same effect

Lius notes that Maxwell understandably doesn’t have the ability to render objects that are invisible, however using an opacity trick, you are able to create the same effect, and here Luis shows how to use the Multiplier Curve in 3DS to facilitate this, and similarly, Set Driven Keys in Maya. Check out the post for Rendering Semi-Transparent Fluids with MaxwellRender in Maya and 3DSMax here.