NME procedural texture question

the texture left bottom coordinate is (0,0)
right top coordinate is (1, 1)
when we get the length of the coordinate vector
Something like this

I expected get this texture when I connect the value to red channel

but when I play with NME i got this

It looks like the value in the center of the circle is 0 , not 1/sqrt(2)

Did I think something wrong?
Babylon.js Node Material Editor


screen.position (vec2) block is in [-1,1] range. So you need to convert it to [0, 1] for your thing to work. Check it out here