2) Yes, it works , but:
- It`s not really user friendly:
- Not always accurate due to rounding.
3)
2) It seems to work fine. You count vertical and horizontal rows. Then you divide 1 by the number.
In case of material 1 here the number was 12. 1/12=0.0833 (then you can freely randomize it horizontally)
In case of material 2 here the numbers were 16 and 6.
In case of material 2 I had to double the resulting number, otherwise I would get some visible repetitions, not sure why. Currently I am a bit too tired to figure it out, but doubling it worked. :)
3) This is a known limitation. We would love to fix it so that the UVW Randomizer would be usable with Corona Material Library materials.