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Iris refraction with Millennium 4, Genesis and Genesis 2

Posted: Sat May 10, 2014 11:20 am
by TRRazor
I'm posting this here because I've been working on a solution and so far couldn't come up with something useable.
Been desperately trying to achieve an effect like the one in the photo below.
Image
In reality - when viewed from the side - the iris will refract and "fill out" the "eye surface".

This is where the problem comes in: All DAZ figures are using an "eye surface" or "eye reflection" material that is coplanar meaning, that it is not suitable for realistic refraction calculation, since it has no volume and light travels only through the surface but not the volume
(a necessity for realistic refraction if I remember correctly).

The result of a Genesis 2 character pictured in the attached image, with proper light placement and the material settings as shown in OctaneRender, obviously do not deliver a realistic result.
So far so good: While googling the problem I discovered that somebody over at RuntimeDNA http://forum.runtimedna.com/showthread. ... on-Problem had the same problem and was able to solve it by increasing the "scale" (not sure which scale he means, the refraction scale maybe?) to 100.000.

Since OctaneRender is using the physically correct IOR (or just "index") value for determining the refraction of an object, this is out of the question since index values between 1.0 and 8.0 didn't get the desired effect (again: no volume)

I tried to manually place a sphere between the eye reflection material and the cornea/iris and set that to the IOR of water - no effect so far.

What would be the best solution in this case?
At best the provided solution would NOT include adding any extra geometry to the scene, since I want to incorporate this in a commercial skin shader set.

Any tips?

Any help would be greatly appreciated.

Thanks a bunch - going crazy here :(

Re: Iris refraction with Millennium 4, Genesis and Genesis 2

Posted: Tue May 13, 2014 8:13 pm
by Apophis
for victoria I've changed the eye surface with a live db material (clear glas ). opacity to greyscale color 0,5.
Is it what you mean?
Test 1.png
Test 2.png
Test 3.png

Re: Iris refraction with Millennium 4, Genesis and Genesis 2

Posted: Thu May 15, 2014 9:03 am
by TRRazor
Hey there,

thanks for your try - unfortunately this is not the result I'm aiming towards.
(ONly had the time to answer your question now)

The Iris is not bulging in the reflection of the eye surface / Cornea like it does in the photo.

As the matter of fact I found out that the Cornea material can greatly impact the result I'm achieving with this.
Check this link to see how it should be http://forum.runtimedna.com/showthread. ... post147531