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Poser - OFFICIAL F.A.Q (Last Updated: 2024 Nov 18 10:25 pm)



Subject: Ugly preview screen and renders in Poserpro2012


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manoloz ( ) posted Thu, 06 October 2011 at 10:36 AM

Quote - There is only ONE main light source in a room.

I'm sure you mean in daytime. But still,

As an architect, I would have to refute this.

Interior scenes have commonly a LOT of light sources, and part of the magic of well designed interior spaces is having the user focus his attention depending on, among other things, lighting.

"Architecture is the masterly, correct, and magnificent play of masses brought together in light." Le Corbusier

What is also true is that it is very common to have most of interior scenes in shadow, so you need lots of lights to illuminate an interior, as walls and other elements occlude the light coming from outside. This is not usually perceptible as we unconsciously brighten scenes. We are hard-coded to perceive this way. But just walk outside in the sun and look towards he interior of an unlit building through a window. Quite dark. And if you take a picture the effect is even more pronounced.

In other words, even when we have a much more dynamic range of possible colours and luminosity perception in our eyes, we also have automatic gamma correction built in.

A gamma correction world does mean we have to take more things into account. But it also means that getting consistent, predictable results is much easier and faster in the medium and short term.

An architect's translation of Bagginsbill's gamma correction explanation :)

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vilters ( ) posted Thu, 06 October 2011 at 10:46 AM

You are quite right.
Most objects in daily life diffuse light in interiors.

All materials are light diffusers/mirrors. (otherwise we would not see them).

In real life the dust particles in the air help in this diffusing.

Most light (during the day) comes throug the windows and gets diffused/reflected inside a room.
At night, the light from out lamps and lights has the same effect.

Poser 1, 2, 3, 4, 5, 7, P8 and PPro2010, P9 and PP2012, P10 and PP2014 Game Dev
"Do not drive faster then your angel can fly"!


Believable3D ( ) posted Thu, 06 October 2011 at 12:14 PM

BUT... that is not achieved by what Poser calls "lights." No room in the world has "infinite lights." And you'll rarely see a genuine spotlight either. What should be happening is that we're creating light from glowing props, and the effect is much different than throwing a bunch of Poser lights in a scene.

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RodS ( ) posted Fri, 07 October 2011 at 7:04 PM

Dang, Roxy, You didn't stir the pot much, did you? :-D

OK - I see I'm gonna have to spend some quality time reading through this forum thoroughly, and doing some playing...

"The more Poser improves, the more I'm inclined to think that we're gonna need to revisit the materials of the old products and revamp them to deal with the state of things."

Yeah, I'm slowly going through some of mine as well.

"I reject your reality and substitute my own" - Adam Savage


bagginsbill ( ) posted Fri, 07 October 2011 at 7:34 PM

I'm still waiting for answers to my questions. Been too busy to deal with this, and hoping the people involved would respond with data.

I'm not defensive, but I know how kawecki behaves and I know what happens in this forum when somebody, confused by incomplete knowledge, starts a showdown with me, about the f***ing math.

Argue whatever you like, the math does not lie. I didn't invent the math. The math is not my baby. I don't care if you don't believe in the math, either. All I care about is you don't leave totally false statements to lay about and trip up other readers trying to understand the universe.

Brewgirlca, we need to know what is the gamma in your scene. I suggested a scene with known things that we share. You can't share that with me. Yes you have render gamma = 1. That does not mean that gamma = 1 throughout your system.

What is the gamma of the color maps? What are the contents of the shaders? What if you have bought shaders that were built by people who used my VSS and those shaders happen to have shader GC? How would you know what the complete gamma is through those shaders if you don't look?


Renderosity forum reply notifications are wonky. If I read a follow-up in a thread, but I don't myself reply, then notifications no longer happen AT ALL on that thread. So if I seem to be ignoring a question, that's why. (Updated September 23, 2019)


kawecki ( ) posted Fri, 07 October 2011 at 8:18 PM · edited Fri, 07 October 2011 at 8:19 PM

Quote - I'm not defensive, but I know how kawecki behaves and I know what happens in this forum when somebody, confused by incomplete knowledge, starts a showdown with me, about the f***ing math.

If you want to learn something about cathode ray tubes (CRT) I recomend you the book "Cathode Arcs" by Andre Anders. Is good to read some serious technical books instead of repeating what someone put in some site in the internet icluding Wikipedia, even has its merits, is only one more site where anyone can write what he wants. And if maths are not your baby is good to learn them too, because without maths you go nowhere in technical subjects.

Stupidity also evolves!


kawecki ( ) posted Fri, 07 October 2011 at 9:16 PM

file_473752.jpg

As the gamma correction has its origen in the non-linear characteristics of the cathode ray tube, here is the transfer function of a typical tube. Find the value of gamma by yourself

Stupidity also evolves!


kawecki ( ) posted Fri, 07 October 2011 at 9:17 PM · edited Fri, 07 October 2011 at 9:19 PM

file_473753.jpg

And the theorical value, as you can see the gamma value is 1.5

Stupidity also evolves!


FightingWolf ( ) posted Fri, 07 October 2011 at 9:23 PM

Quote - Brewgirlca, we need to know what is the gamma in your scene. I suggested a scene with known things that we share. You can't share that with me. Yes you have render gamma = 1. That does not mean that gamma = 1 throughout your system. What is the gamma of the color maps? What are the contents of the shaders? What if you have bought shaders that were built by people who used my VSS and those shaders happen to have shader GC?

I agree with this 100% especially if Brewgirlca wants to improve the rendering issues that were mentioned. My guess is that Brewgirlca may not know where to go to find the necessary information.  For me personally, I would like to know.  Will the Image Gamma show information for the shaders or is that something that I would need to look for in the advance settings of the Material Room?  I can only guess that it would be in the Advance settings of the Material room.



RodS ( ) posted Fri, 07 October 2011 at 9:27 PM

BB, when you refer to the 'gamma of the scene' I'm not  quite sure exactly what you mean. I'm trying to understand all this as I'm fascinated by it. And understanding it can only help to create better art.

In looking over some of my scenes in the mat room, I'm not finding any gamma references anywhere . I did a bit of exploring, and found you can add gamma to a color map through NEW NODE>MATH>GAMMA. Is this what you are referring to?

Still learning this stuff, so just point me in the right direction - no need to rewrite something you've already explained..

I did a bit of playing earlier with the gamma setting in the render setting. I'll post my results just for grins...

"I reject your reality and substitute my own" - Adam Savage


RodS ( ) posted Fri, 07 October 2011 at 9:29 PM

file_473754.jpg

Gamma at the default of 2.2... Poser Pro 2012, of course :-)

"I reject your reality and substitute my own" - Adam Savage


RodS ( ) posted Fri, 07 October 2011 at 9:30 PM

file_473755.jpg

And 1.5 (just for the heck of it..)

"I reject your reality and substitute my own" - Adam Savage


RodS ( ) posted Fri, 07 October 2011 at 9:31 PM

file_473756.jpg

Gamma 1.0...

"I reject your reality and substitute my own" - Adam Savage


RodS ( ) posted Fri, 07 October 2011 at 9:32 PM

file_473757.jpg

Gamma 0.0 (actually 0.02)....

"I reject your reality and substitute my own" - Adam Savage


RodS ( ) posted Fri, 07 October 2011 at 9:34 PM

file_473758.jpg

And Gamma off.

Clearly there's something else at play here...

If nothing else, it's given me some interesting ideas. :-)

"I reject your reality and substitute my own" - Adam Savage


brewgirlca ( ) posted Fri, 07 October 2011 at 9:35 PM

I don't answer questions from people on my free time, no matter how smart they are, who use F words and xxx to address people who might challenge their authority. If I acted over the top like that when junior scientists questioned my academic integrity I would get such a smack down from up the line.

You feel you have to act like that, fine. This sandbox is all yours. I've got the results I need from other commentators on the thread and from friends in the community. I am done here. You guys are more than welcome to keep playing with this string.


RodS ( ) posted Fri, 07 October 2011 at 9:35 PM

file_473759.jpg

Render settings...

The only thing that was changed are the gamma settings. I did not use IDL.

"I reject your reality and substitute my own" - Adam Savage


RodS ( ) posted Fri, 07 October 2011 at 9:36 PM

file_473760.jpg

And finally, my lighting setup. 2 spots; front and rear, 2 infinites; front and above.

"I reject your reality and substitute my own" - Adam Savage


FightingWolf ( ) posted Fri, 07 October 2011 at 11:11 PM

Quote - Gamma 0.0 (actually 0.02)....

I actually wrote about this on my site. This will cover why your character has a sun burn when you lower gamma. The burn is from your materials already having gamma settings.  I guess you can say "normally" you would want to make sure that none of your materials have gamma applied to them.  That way, when you render with a gamma correction of 1, then it will render as if gamma correction was not checked, But if your character materials already has gamma applied to it then the Gamma Correction in the render settings will be applied to the gamma that is already in the material.

The Gamma Correction setting in the rendering setting isn't the actual gamma.  It's the correction of Gamma. Or in some cases anti-gamma.  Baggins Bill can explain it better than I can.  I can only tell you how I use it in my art.

If you increase the gamma correction in the materials then the colors will become darker sort of like a burn effect.  If you balance it just right then you'll be able to actually enhance some older character skin materials.  The trick is to set the material's gamma at 2.2 with the exception of transparencies and then use Gamma Correction in the rendering setting to fine tune the amount of gamma that will be applied to the render. The benefit of using the Gamma Correction is that you don't have to go back and forth to change the gamma on all of the materials.  Just use the Gamma Correction .

In my case the amount of gamma that a person would use is up to the personal tastes and the look that you are trying to accomplished.  For me I pretty much abuse gamma correction and rarely go by the book on it. 

 



RodS ( ) posted Fri, 07 October 2011 at 11:20 PM

Hey, thanks, FightingWolf! I definitely need to look around on your site! :-D

"I reject your reality and substitute my own" - Adam Savage


FightingWolf ( ) posted Fri, 07 October 2011 at 11:26 PM

Quote - Render settings...

The only thing that was changed are the gamma settings. I did not use IDL.

 

Poser has 2 and probably more than two places where gamma can be changed.  The Gamma Correction in the render settings is not the actuall gamma setting.  Think of Gamma Correction as the setting that you use to add more or less Gamma to what is already there. 

The best way to understand this, if you have Poser Pro 2012 (not sure if it's in Poser 9), is to go to Scripts -> Partners -> Image Gamma.  This will show you the gamma that the materials already have.  Chaning the Gamma Correction settings will either add to or decrease what is already there.  For example.  If the Gamma on the material is 2.2 and the Gamma Correction in the render settings is 1.5.  Then you have to combine (take into account) the 2.2 gamma that is already on the material with the 1.5 additional Gamma that was applied.  Don't ask me to explain the math.  I just know what happens when it's done.

The same Gamma Correction setting will produce different results based on the gamma setting that is already applied to the materials.  If you are getting image burns when you render at a Gamma Correction = 1 then it's because there is gamma in your materials.



RodS ( ) posted Fri, 07 October 2011 at 11:40 PM

OK - that explains a lot, and clears up some of the mental fog (lol).

The more I play with this stuff, the more I realize how much I don't know.. But you've cleared up a lot, my friend! Thanks!

"I reject your reality and substitute my own" - Adam Savage


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