creating fresnel effect?

[leigh]

Does Maya not have a Fresnel shader?

If it does not, it's easy to create the effect using gradient ramps. Does Maya have gradient ramps? I'm sure it should have some kind of similar function.

All you do is place incidence angle gradient ramps of opposing values inside your reflection and transparency channels ;)

In other words, you place, for instance, a gradient which is 10% reflective at 90 degrees and 100% reflective at 0% in your reflection channel, and then one which is 10% transparent at 0% degrees, and 100& transparent at 90 degrees.

[jnxdrcg]

no to my knowledge maya does not have a fresnel shader however it is abundant in gradient ramps. thanks for the advice, i played around with it for quite a bit and acheived some neat effects and a hell of a lot closer to the way i wanted it. when connected to a sampler info node through its facing ratio channel i was able to get the basic effect i was looking for from whatever angle the camera was rendering from. looks really good, thanks again for the advice!

[Per-Anders]

fresnel in maya is done (prior to 4.5 that is) using a surface sampler node... ok let me explain what teh setup should be to get good fresnel...

in the chanel that you want a fresnel add a Ramp, then go to hypergraph, look atyour material with up&downstream nmodes, so taht you can see the ramp, then add a SamplerInfo node. then mmdrag the sampler node onto teh ramp, in the connection editor connect the Facing Ratio value in teh sampler info node to the U &V co-ordinates of teh ramp... and voila... you have a fresnel gradient... now play to your hearts content with the gradient (if you want to you can just ocnnect teh facingration directly into whatever attribute you want of your material, but ramps give so much more control.

edit [ so re-reading]

now what you want to do to make this effect better...
fresnel corectly should be used in the reflection channel, but to make it better still you need to make it work on the backfacing polys or the backside of any surface... how to do this in maya i don' know... however you want it to be on teh inside as it's reall the effect within glass. s getting a single side mapped is covered in the manuals, and this is what you need to do, with a simple transparent material on the outside... you should then be able to get a pretty good glass etc...

[lricho]

if you dont want to think about how to set it all up, you can get a script from highend3d called ambiramp. it works nicely.

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