Lighting Challenge #7: An Eye for an Eye

[donvlatko]

what is the best way to make eyelish and eyebrows?

[Womball]

Hey .. im not sure if ur refering to me anyways.. i post the procedural shaders i use for the challenge on page 11 i think .. the image i downloadr from a webpage i dont recall right now but i will post that later ok

Thx

Nope but thanks. I'm using XSI btw and trying to do everything with image textures I paint. I'm not sure if procedurals would create the effect I want. Although I may use them to give the cornea a roughness.

[mer]

what is the best way to make eyelish and eyebrows?

Personally I 'd use the hair tools from XSI.Really easy to comb the 'hair' and fast to render too.

[donvlatko]

I'm useing Maya.

[mer]

I am sorry but I dont know how maya hair tools work so unfortunatellyI cant be of any help.

If you want to avoid geometry for the eyebrows though, you can use a reflection/specular & a bump map. It can give quite nice results with good maps.Check TinyCerebellum's pic(the first one in the previous page),he used this technique and his render is very realistic.

A few tips I can give you for very realistic results/renders :

Use transparency for the eyelashes with refraction.
An Index of refraction: IOR= ~1,35 - 1,4 should give good results and use absorbsion so they are not fully transparent but slightly color tinted depending on geometry-hair thickness , alternatively just use colored refraction.

If you want to push things further use glossy refraction(and maybe reflection) to simmulate the blured refraction/reflection that the 'imperfect' hair geometry produces (I refer to the hair 'scales' that you can see on hair of all types under a microscope ).This will increase rendertimes and you'll need to set the refraction depth value for the raytracing rays to 3-6+ but it will add to the quality of the final result.

If you want/can mix the result with an sss shader and experiment.If you want faster results just use an sss shader and avoid the refractions.

Hope this helps

Cheers

[Leotril]

@donvlatko: We were fortunate to have the model for the challenge and it came with eyelashes already in poly i think. Im a maya user also but not much experience yet.. You can use several things in maya like fur, paintfx and hair to create.. i recomend paintfx is kinda cool also some people in the thread use this techniq k ..

@Womball: Check the thread there a lot of XSI users in here :scream:

[donvlatko]

thanks guyw, now i AM hveing problem to attach, I mean when my eyes close so my eyelish also moves :)

[Womball]

The thread doesn't answer my question about the iris texture, I just need to add something. Also I would like to know if there are any other free HDRI sites like DEBVEC.org

[mer]

The thread doesn't answer my question about the iris texture, I just need to add something. Also I would like to know if there are any other free HDRI sites like DEBVEC.org

To be honest for iris texturing I prefer photo textures for the iris.Its easier and the results are more realistic.Of course you can always make an iris with procedural texture maps in your 3d app but I dont see the reason to bother.'Cleaned-up' photographs work best for texture maps because they usually have all the little things like 'randomness-impurities' that miss from most procedural maps.

My advice is always use LOTS of REFERENCE;)Generally if you want to mimic reality then you need to understand how things work and why they look as they do.Most of the times biomechanical functionality defines how something looks.

By the way there are MANY different types of irises, if you take a look at many photos you ll see what are the main differences and common parts and then you ll be able to paint one that will look as if 'could be a real one',one that incorporates all the little things that 'need to be there'.

The same goes for face modelling! For example there are many different types of head shapes/ nose shapes / ear shapes /mouth-lip shapes.
BUT you can just use a nose from guy A(who is fat) and put it on the face of guy B(vey thin one).It will most probably result in a very 'wierd' looking face!
There is usually 'harmony' between the facial feautures of a person.Even people with 'ugly' idividual features can look 'beautiful' or at least 'nice looking' (you can notice this with many actors face) , while others ..that have nice idividual features dont have them 'well-combined' and this results in 'a not so good looking face', if you know what I mean.Harmony is everything.

EDIT:Oh and on Debeve's site there are a few NEW very good quality HDR images in Open Exr format(similar/better to .hdr format).If you havent tried them yet they are worth a look.

Cheers

[Leotril]

Hdr
http://www.debevec.org/Probes/
http://gl.ict.usc.edu/Data/HighResProbes/
http://www2.cs.uh.edu/~somalley/hdri.html
http://www.anyhere.com/gward/hdrenc/pages/originals.html
http://www.hdrmill.com/
http://www.cis.rit.edu/mcsl/icam/hdr/rit_hdr/
http://hdri.3dweave.com/
http://gl.ict.usc.edu/HDRShop/
http://www.cgtechniques.com/
http://www.daionet.gr.jp/~masa/rthdribl/#Download

Eye Tutorial
http://www.3dtutorials.sk/index.php?id=51
http://gregg.ifrance.com/tutorials/tut_eye_gregg/tut_eye_gregg.htm
http://graphics.cs.ucdavis.edu/~lefohn/work/eye/
http://health.howstuffworks.com/eye1.htm
http://www.lemiere.com/tutorials/tutorials_eye.htm
http://www.3dluvr.com/rogueldr/tutorials/eye/eyes.html

Maya
http://www.learning-maya.com/tutorials.php
http://www.cgtutorials.com/c2/Alias_Maya


Hope that helps .. later

[donvlatko]

I am looking for eye photo, high resolution to use as map, can I find some where for free?all the map I find are small size and resolutions....:(

[mer]

Actually I found many high rez eye photos on google.Try search with keywords 'eye close-up' , 'eye macros', 'iris close-up /macros/photos and other combinations related to eyes,also follow the links and search in the sites related to 'opthalmology' etc. you 'll find way more than you may think if you dedicate a few mins ;)

Here is an example from wiki site.. http://upload.wikimedia.org/wikipedia/en/7/70/HumanEye.JPG

(zoom in for full detail.You can see in this pic that the hair /eyelashes are indeed tranparent/refractive and not opaque.)

Cheers

[donvlatko]

thanks man!

[Womball]

thanks guyw, now i AM hveing problem to attach, I mean when my eyes close so my eyelish also moves :)

Did you ever manage to figure this out? I'm going to have to be dealing with this issue soon.

Btw thanks for the help guys! I hope to have something posted soon, its crunch time right now so its rough.

[donvlatko]

I am still looking for best solution, one would be rivet but I am looking for better our combination

[jojo1975]

I've found the time to tweak a bit my image. Add a texture to the patch, changed iris, add DOF. Critiques are very wellcome. I would like to improve eyelashes and the reflection of the Inner and external part.. any clue ;)
http://www.webalice.it/giorgio.luciano/CGTALK/eye5.jpg

[mer]

Hi!

Is he supposed to wear a contact lens , or is the 'ring' you can see around the iris due to intersecting geometry?

The iris-white part border should be a little more blured IMO, and increase the value of the bump map on the skin, it looks way too smooth.
The cornea looks kinda small, considering the lighting is not very intense in this image.Usually it would be of that size under very bright sunlight.

Perhaps you could also place the cornea at the center of the image so the whole subject is more centered.

Cheers

[mer]

I worked on 'my' eye a little more ,I used displacement for the iris for better detail and I used refraction for the eyelashes.I scaled and rearanged the position of the upper eyelashes and duplicated some of them to make some more.I noticed that in real ones the upper set has 3-4 rows instead of just one (like in the original model).

Here is a 'geometry-only' render without shaders, just displacement&bump maping:
http://img153.imageshack.us/img153/2445/displonlygk2.th.jpg (http://img153.imageshack.us/my.php?image=displonlygk2.jpg)
The displacement map for the iris really helped to bring out the details and correctly get illumination and shadows.You can see that although the geometry looks very 'rough' in this image where I used a simple phong shader, in the next pic with the sss skin shader aplied , the details , creases and bumps almost dissapear as they become 'blured' resulting to a more smooth natural looking skin.

A render straight from the renderer / no post work:
http://img143.imageshack.us/img143/1482/finalwithoutpostworktb3.th.jpg (http://img143.imageshack.us/my.php?image=finalwithoutpostworktb3.jpg)


And the final render with post work , again no DOF, FG/GI , just 2 area lights, rendertime ~1hr on my old 2Ghz AMD-512Mb ram pc:

http://img95.imageshack.us/img95/3367/eyecgipontikidisau5.jpg (http://imageshack.us)

[jojo1975]

@Mer, thanks for the suggestion I will send another try soon :)

[donvlatko]

MMM I like the eye!!!

hey Mer can u send some links for eye, I can't find any big resolutions :( aaaaa

[mer]

Here are a few:

http://www.photo.net/photo/pcd0865/rachel-eye-2.4.jpg

http://www.bealecorner.com/trv900/bnotes/close/eye.jpg

http://imagesdesavions.com/digi/eye.jpg

http://www.turbophoto.com/graphic-design-stock-photos/Images/Eye.JPG

http://www.kepplah.com/stuff/eye.jpg

http://www.terrapinphoto.com/jmdavis/eye%20SM5K.jpg

http://www.iridologyonline.com/iridology/filelibrary/loungefiles/mom%20left%20eye%20Feb%202006.jpg

http://pablohoffman.com/pics/eye.jpg

http://www.imageafter.com/dbase/images/nature_characters_humanparts/b1eye01.jpg

http://www.victorialansford.com/uploaded_images/eye-715779.jpg

http://www.4volt.com/download/wallpaper/photo/4volt_dot_com-eye%20(2048).jpg

http://www.zenratai.com/lilje/referencephotosforartists/eye.jpg

http://www.rdex.net/pics_for_blog/eye.jpg

http://images.google.co.uk/imgres?imgurl=http://www.faemalia.net/USPictures/PhiloPortraits/closeup-eye.jpg&imgrefurl=http://www.faemalia.net/USPictures/PhiloPortraits/index.html&h=1200&w=1600&sz=142&hl=en&start=409&tbnid=_zm5TyhFsoXftM:&tbnh=113&tbnw=150&prev=/images%3Fq%3Deye%26start%3D396%26imgsz%3Dxxlarge%26ndsp%3D18%26svnum%3D10%26hl%3Den%26lr%3D%26client%3Dfirefox-a%26rls%3Dorg.mozilla:en-GB:official%26sa%3DN

Hope this helps :)

Cheers

[donvlatko]

thanks mate

[mer]

I edited my post and added a few more check them out.

PS I just used google advanced search option and 'asked' for high rez only/large size images.

[donvlatko]

yea thanks, I only find one bur I will need a lot of rework on because reflection :(

[jojo1975]

Can someone share some help/tips about eyelashes I'm really struggling with them :( is better to make a plane with trasparency.. leave the alone and use again trasparency, let them modelled ? any help appreciated :sad:

[mer]

Hey Jojo,

If you use the provided model,it already has eyelashes , if you want to make some on your own you can model them, use a cone primitive very long and thin, then duplicated it many times and then select all the objects , 'select points' , and use 'proportional move tool' (move tool with fallof for distance and make the tips slightly arc shaped (see ref pics for accuracy).Usually the tips of the 'hair' 'merge' in groups ,that also happens when they get wat .
Then you can place them by hand to follow the shape of the eyelid also note that the more outward 'hair' the longer they get ,laso scale them randomly to get a more natural look, the whole process wont take more than ~half an hour .Of course you can use a tranparency map for them fore easy-fast results ,although geometry is better.

Cheers

[jojo1975]

Thanks Mer for the suggestion. I will try to render a new image this week let's see what happened :) and I've also discovered that proportional moving in 3dsmax is soft selection :)

[TinyCerebellum]

I've finally found some extra time for an update. I've changed the lighting, the makeup, and made some adjustments to the eyeball shaders along with a few little tweaks here and there. I'm happy with the different look in this render, and I probably won't touch this again from this point on, as I'm too excited and eager to enter the next challenge :).

http://www.spiralsymphony.com/work/LightingChallenges/eye3_3.jpg

[mer]

FIVE STARS!Excellent work!

Your new update looks absolutely beutiful,and VERY realistic:)

Did you use translucency/sss on this one?The eyelid texture is much better than the old one.
Only a small criric, the area where the eyeball meets the skin should be a little more pink,and lighter, and perhaps you could make the iris border a little more blury.

Other than that perfect!!

[meanlebh]

Agreed. Very very nice work. Amazing really. The last couple of posts here were absolutely beautiful. Great work everyone.

TinyCerebellum, I can't wait to see what you come up with for the next challenge. Good luck!

-Brian

[TinyCerebellum]

Wow, thanks' guys! I've made those changes that mel suggested, and also changed the reflection object from the window-type thing to a softlight circular source. It seems to be more in harmony this way with the shape of the eye.

In answer to your question, mel, I still haven't used any sss. I also tried creating the diffuse texture, but it required too much hassle to get it looking right, and I simply didn't have the time to tweak it :(. By the way, mel, your skin shader looks incredibly real. Awesome job!

It was really a pleasure to participate in this challenge along with the rest of you. Some of the renders were truly an inspiration, and it's looking that way too in the hallway challenge. I can't wait to start :).

http://www.spiralsymphony.com/work/LightingChallenges/eye3_4.jpg

[mer]

I think it looks better now:)

One last critique.
I have noticed after looking at many eye photos, that the reflection of bright 'light sources' or very bright reflection highlights is not crisp/sharp.I mean the edges of the highlight, there seems to be a halo/glow/glare around them:
http://images.google.com/imgres?imgurl=http://upload.wikimedia.org/wikipedia/en/thumb/7/70/HumanEye.JPG/250px-HumanEye.JPG&imgrefurl=http://en.wikipedia.org/wiki/Eye&h=162&w=250&sz=40&hl=en&start=2&tbnid=jcE4dIW2sGWDZM:&tbnh=72&tbnw=111&prev=/images%3Fq%3D%2527HumanEye.JPG%2527%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN, This is most of the times NOT due to volume effects but due to 'lens diffraction': http://www.graphics.cornell.edu/pubs/1995/SSZG95.pdf

This can be seen on photos as well as when we see bright objects/light sources/reflection highlights with our eyes as they are a type of lens.

One way to replicate this in 3d is to use a glare-lens shader when we render.
It can also be faked with two different ways.
A simple one is to do it in post, add glow/glare in a image proccesing program.
Another one that works kinda better is for example to use a glow shader on our 'light sources' (of course that can be 'time consuming' render wise when we want to use it on our light-source-environment image (like an hdr one).

Cheers

[TinyCerebellum]

You're definitely right, mer, and that bothered me too when I was testing the reflection. I actually tried adding the glow on the source object, but it doesn't render the post effect in reflections, and I haven't been able to figure out how to do that in Maya (or if it's even possible). It'd be easy enough to do it in post, though, and I think it'd be definitely worthwhile, especially in this case. I could render the reflection pass separately and do the post-effect on that (of course, I could just cheat in Photoshop, but I'd feel a whole lot better if I did it properly ;)), I just have to find the time for it...

[mer]

An easy way is to use a plane grid in front of the area-light source with transparency, opaque around the edges and gradually transparent towards the center,that will make your source smaller so make it bigger(biger area-light source).
This grid opaque edges will obviously hide the environment behind it so here is a better and faster way:

-Use just a glossy/blurry refraction shader on this grid in front of the light source,it will just make the light source smoother blured ( have this grid to NOT cast shadows).

EDIT:

NOTE--After some tests (XSI+MentalRay3.4) I found that this grid's glossy/blury refraction shader exibits a wierd result, I couldnt get the Blured refraction show on my objects reflections (!) although when you look at the light source , through this grid, the area light source looks blured(!).

I ONLY got the correct blured refraction result show up 'blured' on the objects reflection, when I use the L-Glass shader (a must..exists for both xsi and maya) on the grid.

It didnt work with other simple glossy/blury refractive shaders like Phong etc..(!)
(Of course in all tests I have high ray depth value in the Render Globals Tab so its not that that is causing the problem)

With L-Glass you get a parameter under the 'Glossy' tab called (ray) 'depth' .That needs to be set to: value = 2 to get the right results .

Only then we get correct results!!!

http://img184.imageshack.us/img184/8364/testsbi0.jpg (http://imageshack.us)
(Both red balls are reflective with sharp-crisp specular-reflections)


-This is generally a very serious problem , it means that if we use for exmple an area light as a sunlight and we have say..blurry/glossy refractive windows in an indoor scene , we cant render the blured refraction on reflective objects..the reflection wil look as if we havent used glossy/blurry refractions for the windows.(..With L-Glass it works correctly though)

If someone can pop in and explain to us why this happens..I personally think that its due to all basic shaders (at least the ones in XSI) have a limitation for the glossy refractions 'ray depth'.

(I will also post this in the Lighting & rendering forums and I 've posted it in XSIBASE too,in case it is an XSI specific 'problem'.)

Cheers

[jojo1975]

Bumped changed. added two rim lights. added glow in photoshop (thanks Mer for the tips).
Changed a bit eyelashes (material is an SSS) changed a bit value of reflection of cornea. Increased the dimension of the Iris. Left the Blade runner reflection.. I love it :D
Comments wellcome
http://www.webalice.it/giorgio.luciano/CGTALK/eye7.jpg

[jeremybirn]

http://www.spiralsymphony.com/work/LightingChallenges/eye3_4.jpg

Amazing! That's terrific work! Congratulations!

-jeremy

[jeremybirn]

jojo1975 - It might be interesting to see that image reflected on more of the eye. Maybe you could work on the connection between the tearduct and the white of the eye, either make the eye white less black where it connects with the tearduct or put the tearduct into the same shadow area? The black edges of the eyelid around the tearduct also tend to outline the tearduct and make it look less organically connected, maybe all of that needs some fill light and shadows or occlusion?

-jeremy

[Leotril]

@jojo .. Nice job on the skin buddy.. are u using raytracing ? im asking cuz taht gave me know that witheness in the eye and i couldn fix it.. why dont u try using like a reflection map attach to reflected color maybe..

[jojo1975]

I didn't use raytracing materials, I will also try to add a reflection map.
Thanks Jeremy for the suggestion.. I also noticed the problems about the tearduct it's a bit darK. I tried to fill it with a small rim omni light but I didn't notice a lot of difference..any hint how to make the edge of the skin and eyelid a bit more white ? It would be very appreciated. :)
Jojo

[Thykka]

Since people were posting fantasy eyes, I couldn't resist the temptation to do HAL (http://en.wikipedia.org/wiki/HAL_9000)'s eye :)

http://img182.imageshack.us/img182/879/hal2xs9.jpg

(here's a link (http://img329.imageshack.us/img329/5708/halrenderzz8.jpg) to the non-photoshopped render for those interested)

[mer]

Nice entry Thykka,
Perhaps you could use a more 'industrial' image for the eye reflection, the current one is very organic but still it makes an interesting 'contrast'.The eyelashes could look more chrome like so the material matches the robotic look.
Keep it up!

Cheers

[quasiagent1]

This is my first attempt at this lighting challenge (and is actually my first post in general). I used the provided lights, but added depth map shadows. The skin is a simple blinn shader, with a slight surface glow to soften the texture. Some Photoshop touch-ups were used to blur the edges of the render, again to make the overall look softer.

Comments welcome.

Also, feel free to check out my other work at www.thefingerprintsofgod.com

[jojo1975]

@ quasiagent Very goos start. I would have make a more sharp focus on the iris and less bump on the skin also the sclera less grey. Overall a cool image :)
here's my last. Added highlit and reflection on the pupil, make the eyelashes less dark, changed the eyelash material, decrease bump, desaturate images, adjusted light intesity ,added a rim light. Overall quite satisfied and also no more time to work on the image :) Thanks to all suggestion for the image improvement. Also i reread the chapter about lightgin eye in Jeremy book that was really helpful.
it seemed easy but it was a tricky challenge ;)
http://www.webalice.it/giorgio.luciano/CGTALK/FinaleEyeS.jpg

Cheers
Jojo

[jeremybirn]

These are some nice entries getting added!

-jeremy

[jeremybirn]

I put the gallery page up for this challenge:

http://www.3drender.com/challenges/eye/index.htm

As always, please PM me if there are any corrections to your names or anything.

Thanks!

-jeremy

[migusan76]

Man guess Iam a little late on my entry! But I guess I can still post it up here :)

http://www.digiteck3d.com/forum_images/workwip/eyeFaceLight.jpg

[Leotril]

Jeremy thanks for putting the gallery .. i think i kinda overdid my eye on those latest attemps so .. i was hoping to finish after the Eon challenge but i guess is kinda late for that so would you please upload instead the picture i upload on page 10 please ?? sorry to bother but as i say i think overdid my eye.. it was kinda rush and i was hoping to get back to it..

oh i forgot i got bmp with greater quality of the same image il will upload right away ..

http://img114.imageshack.us/img114/8436/eye5gbkp3newyi7.png

thanks for all the help..

[jeremybirn]

migusan76 - Not too late, you made it into the gallery!

Leotril - Updated. (But what was wrong with the red spotlight again?)

-jeremy

[Leotril]

I think it was an issue with the cone angle or light fog :wise: ..

how about the old challenges marathon is there gonna be any ???.i would like another shot at the eye :)

later

[migusan76]

:) jeremy that is awesome Thx's...

[mer]

Very nice migusan76 (http://forums.cgsociety.org/member.php?u=11294)!!

I love the skin, it looks very nice and the sss is just as it should.

Can you please explain the sss setup and the lighting/rendering set-up?Software and shaders used?

One ctitic , the Ambient oclution around the sclera where it meets with the skin/eyelid, it looks a bit too much and it also darkens the sss a little more than it should.The iris border needs some more bluring in the transition with the sclera.The iris map is really nice but I think it should be more sharp.Itlooks kinda like a photo mapped while it should look more 3dimentional with more depth and perhaps displacement.

The veins are nice in terms of rez of the texture but I think there shouldnt be so many aspecially around the iris , the tend to be more around the left and the right side od the sclera near the border of the eyelid.

Keep up the good work!Keep us updated:)

Cheers

[migusan76]

Hey mer, I really like your entry!

As for the software I used maya/mentalray for set-up and rendering. Also used zbrush to tweak the base mesh and create or tweak textures for the objects. For the sss setup and shaders Iam using custom shaders I programmed for mental ray. Mainly since the scene was covered with SSS objects I used my custom skin shader that has a bssrdf diffusion term that calculates the different wavelengths in the object, combined with diffuse/subsurface terms depending on the map that I paint for it. Overall I used 10 textures on the face skin, and about 4 for the eyeball. Both used the same skin shader to get the overall look. I agree with your critic's the occlusion turned out to be a little darker than I had anticpated but by the time rendering was done it was to late for me or should I say the deadline I set for myself was in, There are tons of things I would different If I had to this all over again.

[jeremybirn]

This is an old challenge now, this thread is archived. If you scroll down to the Challenge #7 section of the downloads page, you'll see that the models can still be downloaded for your tests, and also that a gallery has been made of top entries. Feel free to browse this thread to see what others have posted, even though you can no longer post here. -jeremy