In this tutorial, we will model and texture a realistic human eyeball. With only a few adjustments to the steps

here, you should be able to create any sort of eye you want.




1. Create a surface sphere (Get > Primitive > Surface > Sphere). Rotate it

90 degrees in X so it faces forward.



2. In the select menu, pick V Isoline from the pull-down component menu.


3. Pull two new isolines from the frontmost isoline to form a group of three.


4. Modify > Surface > Insert Knot Curve to bake the new isolines into the surface.


5. Do the same thing to create two more isolines close to the center. Bake them in again.


6. In points mode, select some of the points towards the front of the eyeball and pull them back to

form a sort of depressed dish in the front of the eyeball.


7. Pull the points in the center of the eyeball out to form a small bump.


8. With the eyeball selected, create a new layer called "Eye_Inner." Change the

active layer back to Layer_Default.


9. Create a new surface sphere and rotate it 90 in x again. Scale it so it is just slightly larger than the inner eye sphere.

Create a new isoline just inside the first ring, and another one closer to the center. Pull the points in the front of

the eyeball out to create a subtle bump out of the front of the eyeball.


10. Assign the new sphere a phong material. Make the phong 90% transparent. Make its Diffuse

pure white and its Ambient pure black. For the specular, make the specular decay 500,

and the color pure white with a level of 3.


11. With the new sphere (and nothing else) selected, create another new layer called

"Eye_Outer". Make the new layer unselectable. Make Layer_Default the active one again.

Freeze the sphere.


12. Assign the inner eye a texture projection and a lambert material. DO NOT freeze

it. We will need to adjust the texture projection later, and if you freeze the object it will lose the projection.


13. Start photoshop. Create a new 512 x 512 image.


14. Make sure the rulers on the side and top of the image are visible. Pull a guide

out of the top and put it in the center of the image. Pull another one out of the side and put it in the center also.


15. Set up a gradient with a very light blue on the left and a light pink-red on the right.

Create a radial gradient with the blue in the center and the pink on the outside.


16. Create a new layer. use the circular marquee tool to make a perfect circle.

Pull it to the center of the image... it should snap to the center. Fill the circle with the

colour you want your eyes to be.


17. With the circle still selected, create a new layer and fill it with 50% gray. Then go

filters>noise>add noise and fill it with noise. Don't select the monochromatic check box,

you want it to be multicoloured noise.


18. Go to filter> blur> radial blur. Set the Amount to 30 or 40, and blur method to zoom. Click

ok. Now go back to the filter menu and click "radial blur" at the top of the menu a few times.

It will repeat the filter, blurring the pixels more.


19. Set the blend mode of the noise layer to overlay. If the effect of the noise layer is

too pronounced, you can lower the opacity setting.


20. Create a new layer, and a pupil-sized selection with the circular marquee

tool. Snap it to the center. Fill it with black. Run a gaussian blur on the pupil to fuzz its borders out a bit.


21. Ctrl-select the iris colour layer to reselect it. Switch to quick-mask mode. Gaussian blur it,

then switch back. Create a new layer under the base iris layer and fill it with black. This will create a

dark rim around the outer edge of the iris.


22. Create another new layer right above the bottom layer. Scribble some very thin red lines into the layer

for veins. Reduce the opacity of the layer until the veins are just visible.


23. Save the image out as a targa into the Pictures folder of your project.


24. Put all of the layers you have created into a new layer set called "colour".

Duplicate the layer set and call it "Bump".


25. In the bump layer set, fill the bottom layer with 50% gray. Hide the veins layer and the

black rim layer. Desaturate the iris base and iris overlay layers. Run an autolevels over the iris

overlay layer. Save this out as a targa into the Pictures folder.


26. Back in XSI, select the inner eyeball and press 7 to bring up the render tree. Change the

perspective camera mode to shaded.


27. In the render tree, go to nodes > texture > image. Double click the image node and

select the eye colour .tga image. Hook the image node's output up to the lambert's diffuse channel.

Go to nodes > bump > Bumpmap Generator. Double click it and select the bump map image.

Hook it up into the material's bump channel.


28. Now, the iris of the file texture probably does not match up to the iris depression you

created in the eyeball sphere. To make them fit together, select the texture projection

on the inner eye sphere and scale it until the rim of the iris in the image matches

the rim of the iris in the geometry.


29. Do a render test. (in the render menu set, go to Render > Region > Show RGB to make the

background of your render black) Looks pretty good, but there's one problem: there's some

visible nickling (which means you can see the polygons; it's not a smooth curve) on the edge of the

sphere. To fix this, select the inner sphere and hit the + key on the number keypad. This subdivides

the sphere, but the settings aren't optimized, so there is no visible difference. Open up the expanded

properties page for the sphere by hitting alt-enter. Go to the bottom of the page where there's now a

Geometry Approximation section. This section does not appear until you subdivide the sphere.

Go to the Surface tab and click the Fine option. This should eliminate all the visible artifacts

on the silhouette of the sphere.


Oh happy day! We have a finished eyeball. If you run into any troubles, let me know

here. Good luck!!


copyright © 2003 cameron widen. all rights reserved.