I am using images to plug into bump and displacement nodes. Let's say I use the Poser Root Surface shader system, for discussion. Assume my values will be positive (ie, greater than zero), My question is: What does the colour black mean when I use it. Does it get interpreted as a negative displacement amount, or does it mean zero displacement amount ? I am a bit confused.

Dark will be dents, light will be bumps.

Ohhhh, that's an interesting tidbit I wasn't aware of. Thanks!

Then you would assume that neutral gray is your zero base value for displacement.

Yes, that definitely makes sense.

Just poking around other sites with displacement discussions, if your neutral value is off, you can get bloating when you render. Something to keep in the back of your mind when troubleshooting.

Black is zero in firefly, many softwares over the years produce 16 bit middle grey as 0 displacement maps... most notably older versions of Zbrush. So Bagginsbill suggested fixing this difference with a Math Functions node Subtract with value 1 set at 1 and value 2 set at 0.5. You then run your map into value 1 and run the math node into the displacement socket of the root.

Not doing so with grey as 0 maps will produce bloating and other artifacts.

If you're using software like mudbox it produces 32 bit maps that are black as base point and values less than zero. 32 bit maps produce ranges beyond what a monitor can display.

Black as 0 maps require no math node adjustment.

When displacement maps go wrong...

This is a Star Trek uniform texture for DAZ's Valiant. Textures are very nice, but the MAT files have issues. (Not to complain - it's a freebie, after all.) For some reason the displacement file comes in with a value of 1. That's...way too much. On the right it's set to a more reasonable .01.

(I usually just detach the displacement map; this particular uniform didn't have ribbing on the collars, though many other Trek uniforms did.)

Greyscale bump maps are also commonly run through a math subtract. Here is the procedural bump EZSkin formula that loads with La Femme pro...

Here's a very informative and entertaining thread about displacement. Also very good advice on masking...

Mask a Displacement Map

Thank you, All. Very helpful. I kind of guessed the various render node systems interprete Black, Grey at 50% between White and Black, and White, are different, not to mention the 16-bit and 32 bit items (was there also floating point and non-floting point images oh my goodness). Anyway, with these things in mind, I'll work the values appropriate for the various shader trees.

@ randym77: I've been noticing lately that displacement/bump values have been defaulting to 1 when a node is plugged into them. It might be a bug and can be overlooked if you don't check the Material Room on a regular basis.

@ EldritchCellar: Did you realize that there are node duplications for that material set up. Follow the connectors; you can only have one connector for each input and multiple connectors for each output. Looks like you have nodes hiding other nodes in the screencap. Someone didn't clean this up too well.

Nah. La Femme pro loads with a seperate superfly and firefly root. You'll have to school Blackhearted or Deecey on the error of their Poser ways hborre. I didn't bother "cleaning up" for that image because...

I have custom scatter/blinn shaders that I made for La Femme, sort of going back and deconstructing the procedural bump scatter/blinn that BB created and which EZSkin was based on. I render IDL Firefly, 2 environment spheres, inner for reflections outer for hdri light. I also have custom textures, morphs, and dependencies I've created for LF pro. You should try the figure out sometime...

The displacement detailing effects you see on her lips, they're subtle, above, aren't from maps. It's a SubD morph created in Zbrush. Hence why the grooves and such show at an angle... something that isn't possible with bump.

Looks good. I've drawn away from Firefly but who knows when I may need to go back. Yeah, that node screencap threw me for a loop. Looks like I'll be doing more Material Room editing in the near future.

Still can't seem to banish that wee bit of blue happening around the sides of her mouth. The solution of different scatter groups isn't quite doing it. The only other solutions are changing the Scatter Scale or adding BB's Max Scatter trick. I'm thinking that the blue is mild enough, especially with more strongly saturated lip colors, that it's an acceptable amount.

At this point a gigantic amount of Mat room and Render fundamentals in regard to Superfly are dependant on a solid grasp of what came before with Firefly. Without that knowledge of what works with Firefly and IDL, which I guess most old timers take for granted, trying to approach Superfly will be an exercise in frustration. Not long ago a new Poser user said to me that "Superfly is a more robust renderer than Firefly", with a totally oblivious attitude of superiority. In other words they weren't concerned with how to use Firefly. See now about 20 threads created by this person asking questions that are Firefly GI 101 :D

Those are the only 2 solutions I can think of to solve the problem. If the mouth is not open, disengaging the inner mouth scatter will solve that. And unless you have an extreme closeup portrait with the mouth wide open, is gum scatter that important?

That is a solution for personal use. Not so much for redistribution. But yes. That's very good advice for personal renders, something that didn't occur to me because I've been so concerned with everything working out of the box and creating custom smiles dependant on custom teeth etc. Forest for the trees I guess. Thanks for the "sometimes the most obvious solution is the most obvious one"

You're welcome.

EldritchCellar posted at 12:49PM Fri, 16 October 2020 - #4398760

Nah. La Femme pro loads with a seperate superfly and firefly root. You'll have to school Blackhearted or Deecey on the error of their Poser ways hborre. I didn't bother "cleaning up" for that image because...

I have custom scatter/blinn shaders that I made for La Femme, sort of going back and deconstructing the procedural bump scatter/blinn that BB created and which EZSkin was based on. I render IDL Firefly, 2 environment spheres, inner for reflections outer for hdri light. I also have custom textures, morphs, and dependencies I've created for LF pro. You should try the figure out sometime...

The displacement detailing effects you see on her lips, they're subtle, above, aren't from maps. It's a SubD morph created in Zbrush. Hence why the grooves and such show at an angle... something that isn't possible with bump.

Any way you could share these settings so I can study them. I'm still hitting walls with getting my character wrapped up and skin is something I'm picky about but I just don't know enough about the Material room to say I know enough yet. Also looks like you created a lip mask, I'm trying to create one for lips and eyeliner for L'Homme so that would be greatly appreciated.

Thanks!