Hi ..

I have a group of geometry pieces that I unwrap. then, in a for each loop, I want to offset each piece's UVs by a random value with rand(1) in u and v.

But that does not work correctly. There is some random transformation going on, but not for each piece individually (that's why I assign it in the for each sop), but ALL pieces get the same random value assigned ('globally').

What could be the issue ?

Any input ?

Thanks..

m.

Actually, rand(1) will always return you the same value because of its deterministic nature. To get different random values you must use different seeds. In your case, something like rand(a*u) and rand(b*v) may be reasonable, where a and b are any real numbers of your choice, except zero. You can try a=b=1 as a starting point.

I see .. thanks ..

but can those numbers (a,b) be created in the expression I use for the UV transformation ?

I thought about changing the seed, but I am not sure where to set it ‘per piece’..

In a for each loop you can use an expression like rand(stamp(“../”, “FORVALUE”, 0)*733.73).
This way the rand function will generate a random offset using the iteration number times some other number (for variation) as a seed.
So you can have for U rand(stamp(“../”, “FORVALUE”, 0)*733.73)
and for V rand(stamp(“../”, “FORVALUE”, 0)*328.42)

thanks for those great inputs, guys !!

m.