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DarkSquirrel
05-15-2006, 03:20 AM
i've been 3d modeling for a while now and there are a few things (some new some old) that i still have yet to fully understand when dealing with photorealistic models.

(bear with me i believe these questions largely deal with shaders, but since i know very little about shaders [beyond that you should use them] you can never be too sure)

1. An effect i've seen recently in a couple of tech demos and a few very snazzy renders that i've seen on the boards. Reffering to a back lighting and transperacy effect with skin. An example would be the nose and ears, when lit from behind (or certain angles) a red sort of transparent glow can be seen, not making them transparent, but enhancing that realistic affect.
http://i14.photobucket.com/albums/a302/squirrelybot/playstation3eccola_speciale.jpg

2. Different hues for shadows on skin. Example: instead of going to skin color to darker skin color (via adding more black) it mixes in red and yellow values, looks nice and realistic.

3. Also what maps are essential when making a photorealistic model (preferably models that would appear in a next-gen game...or next-gen portfolio perhaps)

i had meant to add more of these when i started but, i guess those neurons mis-fired while writing ...hopefully i'll think of them later.

-thanks in advance
dapeter2
05-15-2006, 05:26 PM
The first and second items in your list are both dealt with using subsurface scattering (or SSS). There's plenty of info on this if you search for either the term or just SSS.

Implementation of it is dependent upon your render engine.
benclark
05-15-2006, 07:08 PM
To answer your 3rd question........For next gen games currently in development I have read that 2048x2048 Alpha, Normal, Color, and specularity maps are common
DarkSquirrel
05-16-2006, 03:41 AM
why thank you very much, you've been very helpful^^
oDDity
05-18-2006, 10:36 PM
Doom 3 already uses normal, bump, colour, specular, gloss and alpha maps at 2048x if you want it that size. Don't see the point myself, waste of good RAM, much better to use an overlayed 128x detail texture...which doom3 also supports.
NRG-Alpha
05-19-2006, 12:37 AM
Being in next gen game development myself, I have yet to see 2048x textures myself (on projects that I have worked on or am currently on). I know that developers like Epic certainly do make use of them. But I find that it is really subjective to what kind of game you are making.

If you are a doing a game with a very texture rich environment that needs alot of unique textures, well, having 2048x is a waste. Games like Doom can get away with it more simply due to it's corridor-like structure that can re-use alot of the massive textures (or portions of them). But in my experience, having worked on games like Splinter Cell: Chaos Theory, it simply isn't economical.

Also on the subject of map sizes.. it is often a good idea to make your color 'or commonly mislabeled as diffuse' map smaller and have your specular and normal maps larger, as in real life, it is the specular and 'bumpiness' that help truely define a surface. So making all your maps ultra large can be quite a waste indeed.

Oddity, if you are interested in SSS (sub surface scattering), perhaps the app that you use for your modelling has this feature? If so, I would recommend reading up on it in the online help files.. Might be a great way to start. Otherwise, there is tons of info on it on the web.

Cheers,

NRG
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