SD power node

electricsauce

Stupid question. How do I get a standard power node (Base ^ exponent) in a function? Everything I can find is based on a power of 2.

NicolasW

Their is a "pow" function in the library (it does x^y).

electricsauce

I'm not sure that it's working exactly as I want it to. For example 1.5 ^ 3 = 3.375, but using the substance power formula (((log 1.5) / (log 2)) * 3) ^ 2 = 3.079. It would be nice if there was a way to debug each nodes output.

oblomov

Nope, that's 2^((log(1.5)/log(2))*3)=3.375, so it works
In general, whatever values of x,y,z (x and z > 0), you have x^y=z^((log x/log z)*y)

electricsauce

You're right. I though Pow2 was x^2 not 2^n. Thanks for the help.

oblomov

I admit it's confusing. We should rather have named it "PowOf2" or "2Pow".

electricsauce

I think I've tracked my issues down to the samplers in the pixel processor not tiling. If the x or y axis has a negative coordinate then it just shows up as black.

oblomov

Sampling at negative values works for me, so there is probably a problem somewhere else in your graph. Would it be possible to share it with us so we can have a look at it?

electricsauce

PM'd