Inverse Fresnel Help

jocose

I'm trying to modulate the opacity of a material based of the fresnel vector, but i want the opposite effect that fresnel is giving me. Does anyone have any idea how to achieve this? When I look directly at the surface the opacity is 100% when I look at it at an oblique angle the apacity is lowered.

Right now its doing the opposite.

I can't figure out how to flip the result

glynnsmith

Stick a One Minus node, from the math group, inbetween your fresnel node and whatever it's going into.

One Minus basically inverts

divi

scrap the 1-x.

or just do what glynn said

JordanW

Also divi in your shot the dot result should be clamped, it's actually going to -1 on the backface which causes problems for 2sided and translucent materials. And 0,0,1 is not an up vector without going through a transform node, it's actually returning the surface normal in tangent space.

jocose

Great guys, I think I got it working. Thanks for the help. I'm going to hopefully post the finished shader later

divi

JordanW wrote: »

Also divi in your shot the dot result should be clamped, it's actually going to -1 on the backface which causes problems for 2sided and translucent materials. And 0,0,1 is not an up vector without going through a transform node, it's actually returning the surface normal in tangent space.

oh, yeah, totally effed that one up not sure why i even wrote that. shot is from a while ago when i was a bit more clueless about vectors.