Eyeball Modeling help

[Houkah]

looks ok. I would take polySurface6 and make it convex though. (i think that's the iris). What u can do is take the cornea model and just flip it and make that the iris. Maybe scale it a little so it's not quite so rounded. Oh and some textures. What i like to do is use a nurbs sphere. Detach it at an isoparm (one that's large enough to make a good iris) then duplicate that detached surface and flip it (or just a -1 scale in the appropriate axis). Then add the shape for the pupil.

[erwin1978]

I'm trying to get the physics right when raytrace lighting is on. What you describe wouldn't work for me since there will be air between the cornea and the iris.

The cornea is a lens and fluid is between it and the iris. What I did is combined the fluid area and the cornea to form the single piece.

[DesignDawg]

Why are you trying to create a physically accurate model for an eyeball? An eyeball shouldn't be something you have to raytrace.
If this is for a character, or future character work, your primary goal should be to get a good-LOOKING eyeball render, with minimum render time. Honestly, that eyeball doesn't render very nicely, and certainly not realistically at all. You're trying to get refraction from the cornea? Why?
I've attached a scene file that uses just a simple sphere, and a simple procedural shader network to create an eyeball. Now, I didn't spend much time on it, so I know the iris texture can be improved, etc... But this is a good example of how the lighting, refraction, shadowing, etc. of an eyeball can be created ALL in-sahder, with no special geometry. There's certainly room for tweaking, but at the base of it all, it's a solid technique. This is how Pixar does it. ("this" meaning, not necessarily THIS VERY WAY, but rather, to say, Pixar eyes are create all in-shader. No special geometry, and certainly no raytracing.)
I think you'll agree that this eye is more visually pleasing, and even much more realistic-looking than the one you posted. --And the fact that it's no a model, so to speak, but rather just a simple sphere.... That's an added bonus.

Hope this is helpful.

Ricky

[DesignDawg]

Sorry about the double-post. The server, in all its glory, was too busy to give me the time of day, and it ended up taking me 10 minutes to post this. When I had succeeded, I noticed it had done it twice.
:thumbsup:

Ricky

[erwin1978]

That eyeball is fantastic. That's exactly what I'm trying to make. Unbelievable.

[erwin1978]

I just realized the eye is not realistic when viewed from side. So, I'm back with my original eye. The radiosity and refraction settings were for testing. I haven't even textured the eye. I just wanted a general feedback on the structure of the eye

[S. J. Tubbrit]

The Structure of your eye is ok, and fine enough for what you need it to do, I did a bit research on the eye, you can see some of my research here : -

http://www.computerarts.co.uk/tutorials/type/tutorial.asp?id=23082

and here mostly, which has been updated : -

http://users.tinyworld.co.uk/steven_tubbrit/Workshop/Nurbs/Eye/Photorealistic_Eye_01.htm

http://users.tinyworld.co.uk/steven_tubbrit/Workshop/Nurbs/Eye/Eye_Main.jpg

[DesignDawg]

Yeah, the eye is a little unrealistic from the side... Like I said, it's the way pixar does it. If you watch Monsters, Inc. and others, you will see that the iris and pupil are visible form the side. That is, however, unacceptable for a lot of people. The alternative is to use the concave iris, with a clear high-specular sphere over it. --Sorta more along the lines of what you were doing, but with a concave iris, instead of flat. You're not going to get that nice shadowing like a real eye without concavity in there (unless somehow you COULD tweak the raytracing to get it, which would be unnecessary.

Ricky

[erwin1978]

I keep hearing about the pupil being concaved, but studying my own I makes me say it's not concaved in. Even pictures on the net doesn't have it concaved in.

[S. J. Tubbrit]

have u looked at the second link I posted, the one on my own site? That was isn't concaved, the concave issue is only done to give the eye depth, so that it looks good from every angle, true raytracing and refraction of the eye doesn't look right, in 'ANY' package, so you need to learn how to fake it in your own way.

[DesignDawg]

Erwin,

I just had a thought: You're obviously looking for that depth in the shadows that my eye has. Though SJ's eye is nicely textured, it doesn't have it either... But if you are convinced that your model is the correct way to build it, and will look best from the side, then here's the solution: The way I created the depth in my eye was with a simple linear ramp. You can do the same thing, except use it only on your iris geometry. That way, your model stays intact, doesn't go concave, but you still get the concave "look" in the lighting like mine.
I think I remember your eye (or at least parts of it) being made out of polys? In order for that ramp to work best, easiest, etc., you'll want to make your iris out of NURBS.
--And I would question the neccessity of having a pupil "hole" with a modeled cavity behind it. That's really not necessary, I wold imagine. You can't see "into" people's pupils like that without very special equipment. You should just make that a matte black part of your texture. (Rendering concerns)

Anyway, I hope I've helped. You can take the shaders from my eyeball to use on yours, or at least to get a better idea of exactly how I was using them. Post an image when you get some results you like!

Ricky

[erwin1978]

I made a nurbs cornea by splitting a sphere. How do I close it so it's a solid like a lens?

[erwin1978]

DesignDawg, do you have a tutorial on how you created that eye?

[bentllama]

erwin 1978: please use meaningful thread titles... [read the sticky in this forum for a description]

[TRi-14]

eye's? no character needs eye's....hehe just kiddin...play around! over and over until you get it right...thats the best way to learn

:bounce: <---be like this guy, active and always working

[DesignDawg]

No, there's not a tutorial, but there's none needed. It's all just a shader. The eyball itself is only a nurbsSphere. The shader is pretty simple. Just select it in hypershade, view up and downstream connections, and you'll see how simple it is. The main part that's the "trick" to creating that depth is to use a linear ramp for the bump map, to create a conical "Crater" for the iris.

Ricky

[darkr9]

DesignDawg - I dig the shader solution! Very simple to use and looks nice too. Glad I read this thread. BTW, how'd you learn to do it, any tips on good references for learning shader networks? Thanks.

[erwin1978]

eye (http://home.nyc.rr.com/erwin1978/pic/eye.mb)

What am I doing wrong with this one?

[dmcgrath]

I just dragged the layeredShader1 back on to the eyeball, and this is what I got. Are you asking about the second shader?

[dmcgrath]

Heres what I did with your shader, and a little tweaking of the waves and repositioning. I deleted your phong4 shader and reordered the blinn and phong2 to make what I think you want. Just keep tweaking what you have, you are very close

[DesignDawg]

Originally posted by darkr9
DesignDawg - I dig the shader solution! Very simple to use and looks nice too. Glad I read this thread. BTW, how'd you learn to do it, any tips on good references for learning shader networks? Thanks.

How I learned to do it, in this case, was just a simple matter of hearing from a Pixar employee that their eyes are all done in the shader. With that in mind, I set about doing it in Maya. It was easier than I thought it would be. As for learning shader networks, it's just experience. I've been doing it for many years now, and when I started working with the hypershade instead of the multilister, it all just kinda opened up for me. As for references on how to use shader networks, I would just recommend downloading really good ones or ones that you find interesting, and seeing how they are put together. Download shaders at Highend3D.com and here, and select them in your hypershade, click "view upstream/downstream connections", and figure out what connections between what nodes can create what effects. Pretty soon, you will be thinking of your own uses (for instance, in this shader, using a simple grayscale ramp as a bump map to create the "structure" of the iris.

Best of luck.

Ricky

[DesignDawg]

Oh, and one more thing: Remember, it IS possible to go MUCH whiter than white by using your value slider's numerical value in the color picker. That's how I got the extreme glossy highlights on my eye.

Ricky

[erwin1978]

Why is it that if I apply the same shader on a polygon eye, the placement is all wrong?

[DesignDawg]

Because NURBS surfaces, being made entirely out of rectangles, have UVs built-in. With polys, you have to create UV sets and edit them to create UV maps to place your textures. The texture doesn't know where to go, so it just goes there. It's almost like the difference between spreading a balnket out into a perfect flat shape and just throwing the balnket into a corner.

Ricky

P.S.-- I can think of no really good reason to use a poly shape for an eyeball. ?

[darkr9]

Thanks Dawg... I'll start messing around with them.

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.