I have a question regarding certain contrast issues in my renders. I have P7 and have noticed that with certain skins, the darks never get fully dark, as opposed to other skins I use with the same lights, which go full contrast. I tried switching out AO skins for non-AO skins and that didn't make a difference. Any idea what could be causing this?

Many skin shaders built before SSS, GC, and IDL were available use built-in glow to account for missing scatter, ambient, and bounced light as well as a complete misunderstanding of how to do linear color processing workflow.

You can confirm this by rendering with all lights sources turned off. If you see anything but pure black, you have a glowing shader doing old-school compensations. It makes it impossible to get full contrast since the skin never goes black no matter what.

Look for use of the ambient channel in the shader, or the use of hard-coded color jammed into Alternate_Diffuse, which is supposed to have a lighting node plugged in there, but often does not.

Well I have P7 which seems to be one of the older generation of shader simulators. When did they begin using SSS lighting, etc? With P8?

Quote - Well I have P7 which seems to be one of the older generation of shader simulators. When did they begin using SSS lighting, etc? With P8?

 

SSS began in p9.

If lighting is important to you, you really ought to consider an upgrade. It will give you both SSS and IDL, which brings lighting realism to a whole new level. BB and Snarletgribbley have created many tools to help you take advantage of these advances, so it's not rocket science. Heck, if I can do it, ANYONE can!

And what I don't get is that the contrast changes with different skins.

Different shaders. The textures are just the pictures used to populate data for the shader. It's the shader (what you loaded into the material) that decides how to react to light.

Did you render with all lights off yet?

This is not unique to P7. These shaders that glow would also glow in Poser 9. My point is you are using shaders made by and for hobbyists, but with a critical eye of a pro. You need to take charge of the shader if you don't want to be spoon fed this drivel you're dealing with right now.

Poser 7 can display very realistic skin, if you use good skin shaders. Many of the ones you buy are not good.

Again - the nodes, how they're arranged, determines the reaction to light, not the textures.

And now show a screengrab of the nodes setup in the mat room for the skin.

It is also clear that the hair is far worce than the skin.
It is also visible as a "glowing" hair in your render.

Now, I am a neophyte at all this, but this skin is an AO (I assume that is the shader?). I tried the same skin without AO and there was no difference.

There ya go - glowing hair and skin. Very 90's. Now you know why you can't get to black.

Read my first post - this has nothing to do with AO.

Look at the material - in the advanced material room. Look at the Ambient_Value. Is it zero? If not set it to 0 and try again.

There could be other reasons but I'm not going to guess which setup it is. Need a screen shot. There are literally an infinite number of ways to make it glow.

Hmm, yes the ambient value is zero, so scratching my head

Sorry - that screen shot is like saying "I have coins in my pocket" when you're asking me to guess how much money you have.

But I recognize some common things there.

Set Translucence_Value = 0

Find where the Color_Ramp is going and whatever it is plugged into, make that parameter black.

bill had a light meter as early as poser 6, but I don't know if the new one will work in poser 7.  if so, this will help OP with the blown-out yellow skin areas.  as mentioned above: ambient, translucent, alt diff and alt spec channels may also contribute to glowing hair/skin in some settings.

The light meter works all the way back to Poser 5.

I see a blue and violet "string" coming out of Color Ramp, trying to see what they're plugged into. How do I turn them to black?

The string colors are random and just to help you track through the spaghetti.

It's what they are plugged into that I'm talking about.

But I'm guessing you know nothing about the material room and how to work the nodes at all.

Funny thing is I'm so far removed from understanding what a beginner deals with, I can't even think of a good initial tutorial to point you to.

You need to reveal the parameters of the nodes, and click on a color chip that is connected to that color ramp, and choose black.

Your nodes are all "collapsed" - they just show their title bars, like little windows. On the right of each node are two buttons - one toggles parameter display, the other toggles preview display.

You need to uncollapse the ones that should be modified. You also need to move them apart so you can see what goes where. That is just dragging them by their titles.

But I fear this whole thing is too advanced for you to undertake as your first activity in the material room.

Does anybody else have suggestions for beginner guide to the material room?

Oh - duh. How about your Poser reference manual? Chapter 15: working with nodes.

Thanks for your patience. You're right I am just getting familiar with the material room, and haven't tinkered with nodes at all. I will follow your suggestions and consult the manual.

Just to clarify things, what I am doing is basically modifying the specific skin of this figure? Once I make the changes I can change lights and the changes will improve the end result... When I say "skin", I am of course referring to the shaders embedded in the skin, if that is the correct terminology.

For a beginner the material room is very daunting. Reading the manual will tell you a lot, but putting into practice is another thing. Skin is not the place to start in my opinion. Though skin is the most important to most beginners. I would strongly suggest VSS with pr3 (?). I know the first time I used it pr2(?) I was amazed how good poser could look. I don't know if any one has a link to a pr3 prop with eye's, teeth and all the other great adds, but that would be a where I would point any new user. Look at Bagginsbill's signature.

Once you got skin working and know what something in your scene should look like, you can go about removing the glow from all you other object's materials.

Yes, I am just puzzled because the skin is made by a reputed renderosity designer--it's the Demi skin http://www.renderosity.com/mod/bcs/vh-demi-for-victoria-4-2/87839

I would imagine this guy would have done a professional job. The figure is beautiful but I am wondering if I am doing something wrong on my end....I wouldn't expect that he would be incompetent enough that all the folks who buy the product have to make such delicate material room mods.

Would love your opinion on this. Perhaps one or several of you have this figure and skin.

Thanks guys you have been great and generous with your information.

When it comes to the material room, no one performs like bagginsbill. So it's not fair really to the vender to be compared to bagginsbill. Use the vendors maps, use the vendors shapes, but you're cutting your options short not using BB's shaders. VSS will use the vendors textures.

Hmm , I might have to look over the posts again. Where can I find bagginsbills shaders? Thanks!

here

     Besides the translucency input, there is something plugged into alternate diffuse and alternate specular;  it would help if pacanne would pull those nodes aside and expand them.

Quote - I would imagine this guy would have done a professional job. The figure is beautiful but I am wondering if I am doing something wrong on my end....I wouldn't expect that he would be incompetent enough that all the folks who buy the product have to make such delicate material room mods.

It's probably not incompetence, but a combination of 1: Using a node setup that, in earlier versions of Poser achieves a result similar to what a proper node setup and GC gets, and 2: Inexperience about how GC and IDL affect those older node setups.

With the latest Poser versions you need far less lights and far less nodes to get the optimum results.

Before IDL and SSS and Gamma Correction a lot of this was "faked" in the mat room.

When wotking with older texture sets it is best to start removing all those "faking nodes" and let IDL, GC and SSS do their thing.

Pacanne is using poser 7. So it is before IDL and built in GC, and SSS.

poser 7 had IDL (GIVariables) but it was not for beginners.  they often went mad trying to use it IIRC.