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portrait

Posted: Mon Nov 14, 2011 3:40 am
by t_3
... and you'd never bet - it's girl. again; boring. she, um, pardon'me, it is not looking that bad though, i think ;)
the only postwork is some blurring; not because of noise, but because it was looking artificially sharp :)
gtx 590, 4 ks/pix, 3:45 hours

ps: there are still some flaws which are pretty visible at this size; e.g. the "tear" geometry is just unrealistic;

Re: portrait

Posted: Mon Nov 14, 2011 5:00 am
by Tugpsx
Nice, check your bump level and add sss to teeth and lips
Tear should also be set to less than 50 % or almost invisible

Re: portrait

Posted: Mon Nov 14, 2011 10:26 am
by t_3
Tugpsx wrote:Nice, check your bump level and add sss to teeth and lips
Tear should also be set to less than 50 % or almost invisible
thanks for commenting!

i will completely redo the tear, as it currently is just a tube - what doesn't reflect reality. i think it's more the geometry than the visibility; i'm not sure about bump levels - i just wanted them to be like that ;) imo a real world photo shows pores close to that level - at least if it wasn't photoshopped to get rid of them :)

the lips use sss right now, but i added a little bit of "lipgloss" (cherry red car paint :lol:) what softens the effect (hopefully like in real world too). i even used a clamp function of the bump map to have the wrinkles filled a little more than the rest.

i just googled for somehting comparable; found that: http://web.canon.jp/imaging/eos5d/downl ... rtrait.jpg
now the main difference imo is - apart from the color tone/contrast - that the render is still artificial sharp (even if i already blurred it a bit), and there is a lot less dof. i already used less dof, but found it strange; need to try that again.

of course the bump map needs some more tuning, like on the nose tip (which already bothered me), and maybe a tiny little less level.

btw, the sharpness thing bugs me most; i think every photographer would give a hand to reach that level of sharpness in a photo, and here you get it, but just can't use it because it makes the thing look unnatural :D but at the end it is just the level of imperfection, that distinguishes cgi and reality...

Re: portrait

Posted: Mon Nov 14, 2011 3:22 pm
by Elvissuperstar007
skin has not turned out (
SSS no (skin, lips, teeth, eyes)

Re: portrait

Posted: Mon Nov 14, 2011 4:41 pm
by t_3
Elvissuperstar007 wrote:skin has not turned out (
SSS no (skin, lips, teeth, eyes)
sss YES :)

it is there - everywhere; but i agree with the teeth (and the eyes) - i used a diffuse(sss)-glossy mix, but a specular-glossy mix could be better. the skin is a different story; it is not that easy to turn sss on and skin just looks real; still skin consists of several layers, you also have vains, fat, bones beneath, shining through the skins at different rates. of course all this is missing and makes the final image also miss something. of help could be, to use a special map for the skin "under-structure" on the scattering input, but this is yet to be created ;)

here a comparsion with/without sss:

Re: portrait

Posted: Mon Nov 14, 2011 5:27 pm
by kubo
it looks great, the bump, well there are skins like that with makeup, a real shot has some postpro to get rid of imperfections and make skin even and smooth, and we are so used to it that we sometimes expect baby smooth to be the real thing, I would only fix it around the nose, but besides that it looks a real as it gets. Awesome job mate!

Re: portrait

Posted: Tue Nov 15, 2011 9:37 am
by t_3
thanks kubo :)

still also thanks to tugpsx & elvis, i tried to tweak/fix some of the points you mentioned. changed eyeball & teeth to specular sss mats (with glossy mix), did try to paint a map for the teeth underlying structure (a dentin-map ;) but didn't really succeed; if anyone knows how to get the teeth better - fell free to tell me (but only with examples :) tear is much better now imo, also there is a good ammount oft additional ps blurring, because the sharpness really killed it...

Re: portrait

Posted: Tue Nov 15, 2011 10:15 am
by matej
It looks really nice, yet still far from reality. I'm not criticizing you, I think you did a good job. It's just that a human face is probably the most difficult to reproduce thing from nature. There so much different materials you must take care of, little complex things (at this distance you would need to add facial hair, which is almost invisible, but still needed to catch and reflect light from grazing angles, the brows & eyelashes would need to be real volume objects...), and at the end it all depends from the renderer ability. An ultimate challenge, imo.

If you are looking for a title, I would call it squirrel girl, btw. 8-)

Re: portrait

Posted: Tue Nov 15, 2011 10:31 am
by t_3
matej wrote:It looks really nice, yet still far from reality. I'm not criticizing you, I think you did a good job. It's just that a human face is probably the most difficult to reproduce thing from nature. There so much different materials you must take care of, little complex things (at this distance you would need to add facial hair, which is almost invisible, but still needed to catch and reflect light from grazing angles, the brows & eyelashes would need to be real volume objects...), and at the end it all depends from the renderer ability. An ultimate challenge, imo.

If you are looking for a title, I would call it squirrel girl, btw. 8-)
i completely agree with that :) the next best thing is imo, if you have it on the monitor (lets say 22"), watch it from 5 meters distance, if it looks at least somewhat real. of course the high resolution makes all the flaws much more visible. but apart from the overall look, there are obviously some key parts like the teeth. they just jump out crying "plastic" :) i struggled a lot making them better, just by tweaking materials, but haven't got a clue yet. i think it degrades the "believability" by a good margin.

ps: if somebody knows good examples of high resolution still imagery, covering human faces, i'd be keen to see them...

Re: portrait

Posted: Tue Nov 15, 2011 10:33 am
by t_3
pps: the only thing i can think of to get the teeth any better, is to create a more realistic geometry with a (diffuse) dentin core, covered by the enamel. using painted maps for absorption/transmission seems not to work, because they imo can't reflect the thickness levels of two different materials?

i also wonder about how bumpmaps and ior values on specular materials work together (maybe not?). using the correct ior value for dental enamel (~1.631) resulted in too much gloss. imo because of the current perfect surface, where a bumpmap has not the same effect than if there was a real uneven geometry. maybe a displacement map could help...