Plugin for 3ds max, developed in maxscript.
This script allows you to create three gradients in the three X, Y, Z axes using the vertexcolor.

Video demonstration and comparison with the built-in functions of 3dsMax:
https://www.youtube.com/watch?v=l6S8-qBC9-4 

How to use:
Once the script is installed, select an object and click on start to start the script