I want to build this in studio room, fixed, nothing portable.
That changes everything. You only need a modulator if it's portable.
You have to rotate the filter on the camera 90 degree, and this is really hard to do on the portable version, since it's inside a box. With a modulator you just hit the on/off switch.
For your stationary build I would recommend getting some linear polarization sheets, don't even bother with circular polarizers. You take the first picture, turn the circular polarizer on your camera, and everything is unaligned. Just a little wind breeze is enough to ruin the 100% specular picture. You have to use manual focus too, and the circular polarizers messes everything up when you turn them, damn circular polarizers.
But was the issue in the nature of the setup or just the way you had it ?
It was because I used the other normalmap method where you take a picture from each side.
The method above would need fixing the bellow ball part for nicely tiled texture.
The ball is only needed if you don't have any fixed lights, so you can calculate the position based on the highlight.
Since the lights will be fixed on the rig, I only have to tell the program where the lights are (x,y,z). This is done with a .txt file.
I guess you want to build something like this and just turn the ceiling lights off.
