Math Is Fun Forum

Hi !

I am writing a 3D shader and I got this graph and I just can't figure out the function

The result value (given in greyscale values between 0=black and 1=white) depends on the two variables a and b.

It is for example,

0.5 when a=b
1 when a=1
0 when b=1
0.5+(a/2) when b=0
0.5+(b/2) when a=0

(is there a name for this kind of graph btw.?)

I think it must be a quite simple function.

Thanks in advanced for help
Ray