Hdri environment map not working with skin SSS

As the title says I’m using a 5k hyper focal map to simulate afternoon sun. And so far I love the effect. Shadows are set to 2048. But while providing good stark more realistic scene lighting of the mesh the HDRI map doesn’t do 3 things

  1. Barely illuminates transparency of outer eyeball. Very dim lighting of eye color

  2. Does not fully evoke the SSS aspect of the skin

  3. Not picking up full hair color

i must be missing something. Like some cool button that says “click this on if you want really bitchin SSS skin and hair particles.” Or it might require simply dialing the final strength way up.

Also this is the result of 100 samples path tracing. Any advice, fire away

PS - tried simply cranking up strength of output but overall eyes still remain dimly lit. however with increased white spots as reflection

Branched path was no different

When you want harder shadows and directional light from an hdri you can use the multiply node into the strength, so areas that are lighter on the hdri become stronger in emission. There’s a two minute video on blendercookie here.

You might also want to add a couple mesh lights, with camera ray uncheck so they’re only visible in reflections. One for the eyes, and a rim for the skin.

Photox. - great feedback. Thanks very much

Photox. - great double post

Sure, also, sss usually requires much higher samples than 100 to show it’s true colors. go to 300-400 at least, 1000 better. You probably know this but sss is available on gpu for 2.72 in experimental mode, which can be a huge time saver.

I find that in general when using an hdri for reflections (as opposed to actually using it for a sky) that the big bang you’ll get is mostly for very reflective material like metals, etc… and that skin won’t be helped as much from it.

And make sure you have done proper tests on the sss scale, by putting a very strong mesh light behind it and adjusting the scale until the ears, etc turn pink. It can be very hair triggered with too much and too little both looking bad.

and of course youhave changed the radius to a sort of pink color right? (1, .7 . 7)

And you would want to use that mapping node trick to rotate the hdri such that the sun is behind the camera, facing the chacater, or off to the side a little. Otherwise you’ve got one big rim light which usually isn’t what you want.

Hair color is effected by lighting alomost more than the material itself. Do some tests with an mesh light of varying colors above and at maybe a 45 degree angle to the hair, wityht he light maybe twice the size of the head and about that same distance from the hair. Changing the color of that emission will change the hair drastcially. And it can help to get that big specular gleamn across the front at an angle.

Also you can use two hdris. The sky hdri si likely to not give you much range of color. It’s like blue or yellow/white. Using an hdri for reflections that has a larger range will give you more tonal variation on skin reflections. You can still have the sky as the visible background by mixing the two hdris with a color mix node and the mix factor being light path, ‘is camera ray’

I’m always shocked whn I take a scene I have finished and simply swap out the hdri, the difference can be shocking.

Massive time saver tips. I do have the HDRI source light sun emitting at 220 degrees which puts the light on the front quarter of the face. So the right side of face is strongly lit while the left side is more in shadow.

Im using a front panel as an emitter for fill light. But since you input I added a spotlight with about the same angle of incidence to the head mesh as the sun. Much better illumination of eyes and skin.

Will ramp up samples number. Also great point about the GPU witg 2.72

Will work the new stuff

thanks much again.