I'v been figured out to make a fall off effect in ai surface shader, but I haven't found out.
I'm using MtoA 3.2.0 / Arnold Core 5.3.0.0 on Maya 2017 on window.
I've tried to use the same method to Vray and Software then it worked on them.
2 way I used to make a fall off are
1. make 'sample info' then connect 'facing ratio' of 'sample info' into 'input R' of 'clamp'. set to 1 on 'max' then connect 'output R' of 'clamp' into 'v coord' of 'ramp' and connect it to color node of 'ai surface shader'.
2. make 'ai facing ratio' into 'output R' of 'clamp' into 'v coord' of 'ramp' and connect it to color node of 'ai surface shader'..
is that the bug or did i make something wrong?
You have to connect the aiFacingRatio outValue to aiClamp.inputR aiClamp.inputG aiClamp.inputB
or use aiRampRgb