regarding 3D texture using human skin

[likereal]

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Hi all.
I'm a graduate student major in 3D using Maya. I'm trying to make a human texture for the 3D character in Maya. Believe me it's not about 3D, but really connected with photoshop skill that you guys are good at.


I'm just giving you simple pipeline in maya. I made a human character that needs to be texturing by using human skin photo. To do this I need to get rid off the highlights and shadows of the skin, so I can get a very unified value. It would be odd  if the texture has a shadow under the nose when I light from botoom to top in maya. Best solution is grab all skin from human body and put it on flat surface and take a picture. but it's impossible.

What I'm trying to do is adjusting skin photo using everything in photoshop, but playing with some part on skin comes out various color spot on skin. So I converted this image into HSB mode using filter. Now, I am able to keep the hue, and adjust only suturaton and brightness.

Important part is from here. Take a look at photo. It is suturation cahhnel from my photo it has A bunch of highlights  value 255 B side of nose value 70, C concave value 30. I would really appreciate you if you help me to adjust photo kepp the A  and make the B and C same, for example 50. With this idea I can get unified value with highlight and dark shadow..

Any thoughts greatly appreciated.

Jihoon

[bcachot]

Obviously, starting with a good photo is what will minimize your work in PS. Use the softest lighting possible and illuminate from all directions. While It's impossible to make  the lighting purely uniform, your result make be good enough so that your PS edits are minimal.

In PS, basically it's going to require some elbow grease. I would create 2 LEVELS adjustment layers. One for bringing up the shadows and one for lowering the highligts.

1) In the adjustment layer where you want to lighten the shadow, shift the white point slider left and/or shift the gamma slider left and/or the black output slider right. You have to experiment to get the right balance of level and contrast. **Make more of an adjustment than you think you need.

2) add a layer mask to the adjustment layer, then invert it so the mask is black. This will make the levels adjustment you just made disappear.

3) Now what you want to do is paint into the mask layers with a soft edged white brush. Set the brush to a lower opacity (eg 25%) or a lower flow rate. Start painting into the shadows and gradually lighten them to match the surrounding areas. If you go overboard, you can just paint back with black.

4) you can save time by doing one half of the body and then mirroring the texture.


If all this seems too hard, then take a look around to see if someone has written some kind of image processing algorith that can smooth out luminance levels across a certain radius without affecting microcontrast (pores). If you experiment with photoshop's highlight/shadow filter, you may be able to get a decent result.

[Jonathan Wienke]

The high-pass fillter is a better bet for keeping texture but evening out gross luminance variations. Edit your image in LAB mode and do all the adjustments/tweaking to the L channel.

[likereal]

> bcachot
THis is great. I'm so glad. You gave me a really detailed explanation based on really good idea. When I went step 3 I realized why you said "more than you think" in step 1. This is really strong possibility for texturing without pain.  I think I can do more layers with this idea like curve. I really apprecite you. I will post my modeling with full texture and lighting  when I finish it up.Then take a look.  Thanks again.

>Jonathan Wienke
My teacher taught me to use high pass filter. Result is what you said. LAB mode is one of my challenge, but I'll try and  post  if I something get good.
Thanks a lot.