3ds Max :: Rendering 3D Models - Height Maps With 766 Values Not Enough

I am currently rendering 3D models' height maps using a gradient ramp with an UVW map. The models can be trees, characters etc, it's not terrain.

I would really like to know how to use all 16,777,216 colors so that my height maps have that many different values.

So far I only managed to used the gradient ramp and gain a total of 766 different height values. I use 4 colors in the gradient, here is how:

- First gradient ramp color is full black, and placed at position 0
- Second one is at position 33 and is RGB(0, 0, 255)
- Third one is at position 67 and is RGB(0, 255, 255)
- Fourth one is full white at position 100

This totals 766 different height values retrieved using R+G+B (0 to 255+255+255). What should I do to use the full 16 millions colors?

With my current gradient ramp I cannot use the whole RGB value (i.e. a 24 bits integer, 0 - 16,777,215). I have to separate channels into 8 bits integers (0-255), because with 24 bits a higher value is not necessarily representing a higher height. That's due to the way my gradient is made, and I couldn't find better than what I use.