Shader - Refraction

Ace-Angel

Heya peeps,

Quick question, how do you deal with refractions?

I'm trying to tackle refractions, specifically on skin, based upon this text here: http://darkvertex.com/wp/2008/06/25/sss-with-refraction/

Now the issue I mainly have is that while interpretation of refraction is not open, it is ALL OVER THE SQUID SCROTUM PLACE!

For example, in the case of Dark Vertex, the refractions looks a simple 'camera based movement which has been enlarged', so basically, a Parrallax Mapping thing with bigger scene to capture from.

On the other hand, I have seen other people tackle refection, all the way from distorting with a Fresnel to inverting their cubemap.

So my question is: Help, what should I do and know how to tackle this situation at hand? I'm kinda lost here on what constitutes a proven refraction method of usage in the game industry.

PS: This is what I currently have, please advice peeps!

haiddasalami

Wait I thought refraction was always based on Snell's law and if Im not mistaken the refract intrinsic function is based off it.

Ace-Angel

That's what I thought too, so it makes me wonder if most people are using the refraction terms in the wrong way under shaders.

Here is the term I'm using currently:
http://msdn.microsoft.com/en-us/library/windows/desktop/bb509640%28v=vs.85%29.aspx

I followed this tutorial.
http://xna-uk.net/blogs/randomchaos/archive/2009/01/06/basic-hlsl-lighting-techniques-episode-6-environment-maps-reflection-amp-refraction.aspx

I have so far I have this done:

-I have my Normal Map set to World, declared in N

-Camera Vector set to World in my I

-Index is Scalar, and Set to 0.8

That should be it, right? Nothing more or less? And plug it into my Cubemap?

haiddasalami

Yeah I think thats more or less correct assuming your using the custom node. Is the refract function supported. I never really messed about with the custom node.

Ace-Angel

Cheers! I both remade Snell's Law as a node setup and used the Custom Node too, both of them gave more or less the same results.

So guess case closed ;P