Real Skin

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!irf?et *gmif»g m {fit ma»n m»ng thai has tor faiung « good look tor skin—alook ma! faked some mproved «1« Quafcfr I 30 renders « the of me tr*t$lucency properties of sfcin Combine these

9tsr decade By mat I don t mean better tafcts ««h *ne*e« occasion and enage-based HDR

ghtwg design I mean £>ener simulation at kgnnng modets (we even wrote our own spherical

! behavior Wtm hinds ^m mere are four harmowc shaders). and you get pretty good skin areas of igntmg simulation that tum out to renders I remember the excitement of Jensen s deove most of the jump m *»$uai realism BSSROf presentation at SIGGRAPH 2001—Out.

in order of impact these are amo»ent I figured SSS would be stow and hard to use occ/usion translucency hign-dynamic although it clearly did a better job for skin ange and radiance Here we will focus on than any fake ever could So. like many ransiucency For our purposes translucent others I hung onto ail my cheats and avoided narenais have a significant component of jumping to SSS until recently Here is the

'heir loo* dominated by light that enters the link to that seminal paper Jensen presented material, is scartered and emerges back at SIGGRAPH 2001: http://graphics.ucsd

out a0a,n- edu/~henrik papers/bssrdf/

rie current sub-surface scattering (SSS) Now SSS is widespread All of the high-

methods stem from work Henrik Wann end 3D systems offer it. You can do great

Jensen started in 1998 In a presentation SSS in real-time on most GPUs (Graphics ar SIGGRAPH 2001, Jensen stunned the Processing Units on graphics cards), so graphics world with his elegant method it's starting to turn up in games. Having for SSS Just three years later. Jensen upgraded to SSS shaders recently, I can received an Academy Award for technical say that there is absolutely no reason achievement on SSS methods Jensen's not to use the SSS methods for skin-

methods are a fast approximation to full well that's unless you have a shot with photon-mapping and simulation that work the character lit only with blue light or very well for most common translucent very low-level light like moonlight, materials. Rarely has a new graphics method leapt from academic to global We are going to have a look at the commercial use so rapidly. mental ray SSS Fast Skin shader as it's available almost everywhere now.

I had been working m the 3D field It turns out to be surprisingly fast professionally for a long time before the and easy to use—and the results advent of SSS. I learnt all of the best are a jump above anything you can techniques (and developed some of my own) ever fake.

108 ESSENCE The Face

Real Ute

Suth suffice tctftenng

Human The 0ut9f Im semi-transits

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