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Poser - OFFICIAL F.A.Q (Last Updated: 2024 Nov 25 12:38 pm)



Subject: Gamma Correction and Poser Strategy


Michael314 ( ) posted Sun, 09 August 2009 at 4:21 AM · edited Mon, 25 November 2024 at 5:32 PM

Hello,
I welcome the availability of Normal maps in Poser 8. I'm just wondering why Gamma Correction is not available in Poser 8. AFAIK that is the only feature missing in P8 compared to PoserPro.

My guess about SmithMicro's strategy was that Poser 8 is mainly for building scenes and finetuning while PoserPro is used for rendering animations and bigger scenes (network render, 64 bit), or, to export scenes to other 3D apps (COLLADA, PoserFusion).
By this split, gamma correction definitely would belong to Poser 8. In case I use Pro because I want to export scenes, I don't need it in Pro anyway, and if I use Pro for the bigger throughput, I still want to see a sample frame during development.
Given the effort it takes to do gamma correction manually in the material nodes, and the importance of it (see bagginsbill's frequent posts ;-) ), it is definitely a must-have in P8.

Was it left out intentionally for some reason I don't grasp, or was it just not yet ready due to required adaptions for IDL, or has it been made redundant by the new tone mapping feature?
(I think I read in some post that it was planned for PoserPro 2).

Best regards,
    Michael
 


Lucifer_The_Dark ( ) posted Sun, 09 August 2009 at 4:41 AM

Do we still need GC with the new lighting available in Poser8? I've always switched it off as to me it makes everything look washed out or far too bright, I know I could fiddle with the settings but I prefer the "uncorrected" look.

Windows 7 64Bit
Poser Pro 2010 SR1


Whichway ( ) posted Sun, 09 August 2009 at 4:51 AM

From an artistic viewpoint, do what gives you results you like. From an accuracy viewpoint, you will always need it, at least until no one can remember what a CRT was.

Whichway


ice-boy ( ) posted Sun, 09 August 2009 at 4:55 AM

michael weret normal maps already in poser 7?


ice-boy ( ) posted Sun, 09 August 2009 at 4:56 AM

Quote - Do we still need GC with the new lighting available in Poser8? I've always switched it off as to me it makes everything look washed out or far too bright, I know I could fiddle with the settings but I prefer the "uncorrected" look.

GC with the new lighting?

but GC is not about lighting.


Anthanasius ( ) posted Sun, 09 August 2009 at 5:01 AM · edited Sun, 09 August 2009 at 5:05 AM

Quote - but GC is not about lighting.

It help ! When you dont apply GC you need to add more light to "illuminate" shadowed faces of props or figures, not with GC !

Génération mobiles Le Forum / Le Site

 


Lucifer_The_Dark ( ) posted Sun, 09 August 2009 at 5:03 AM

Oh! errr what is it about then? I'm totally confused now. really.

Windows 7 64Bit
Poser Pro 2010 SR1


ice-boy ( ) posted Sun, 09 August 2009 at 5:11 AM

Quote - > Quote - but GC is not about lighting.

It help ! When you dont apply GC you need to add more light to "illuminate" shadowed faces of props or figures, not with GC !

wowowowo wo

GI without GC also looked dark. before GI we used IBL. so you had to have a brighter IBL without GC. now you have GI insted of IBL. but you still need to gamma correct your image. or use tone mapping.


ice-boy ( ) posted Sun, 09 August 2009 at 5:12 AM · edited Sun, 09 August 2009 at 5:14 AM

Quote - Oh! errr what is it about then? I'm totally confused now. really.

there is no reason to be confused. there are 2 big threads from bagginsbill about gamma correction :-)

www.renderosity.com/mod/forumpro/showthread.php
www.renderosity.com/mod/forumpro/showthread.php


Lucifer_The_Dark ( ) posted Sun, 09 August 2009 at 5:15 AM

I'll look them up  have a read, I'm just finishing up installing the new content for Poser8 then I'll be all set to get started. :D

Windows 7 64Bit
Poser Pro 2010 SR1


ice-boy ( ) posted Sun, 09 August 2009 at 5:18 AM

in poser 8 you have tone mapping. i think BB said you need to use HSV 2.2 for best results.


IsaoShi ( ) posted Sun, 09 August 2009 at 7:00 AM · edited Sun, 09 August 2009 at 7:12 AM

Summary?

  1. Gamma correction is the correct way to adjust the input colours and textures used in a render, and the output render itself, for display on a computer screen. (Actually it's a very close approximation, but close enough to pass for correct nearly all the time). 

  2. With GC rendering, the 'old' method of making a Poser render look sort of okay by adding more lights to brighten up the dark areas is no longer necessary. Also we no longer need to use those shaders that have been unrealistically adjusted to try to compensate for the lack of GC (e.g. by adding a faint ambient glow).

  3. Therefore, if you use those 'old' light sets / shaders and gamma correction, you will have far too much light in your scene, and textures will be blown out.

  4. Poser 8 includes Tone Mapping with an option for HSV Exponential. This is an approximation to 'proper' input and output gamma correction.

  5. In SM's view (I would guess) the full ramifications of using proper GC are just too confusing for the average Poser user, so it will remain a Pro feature.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)


Whichway ( ) posted Sun, 09 August 2009 at 8:42 AM

Quote - 4. Poser 8 includes Tone Mapping with an option for HSV Exponential. This is an approximation to 'proper' input and output gamma correction.

Poser 8's Tone Mapping only approximates output GC. It does not touch input. This is not actually the right way to deal with GC, but it is a simple, sloppy approximation. Besides, SM documents Tone Mapping as a mechanism to compress the highlights, not expand the shadows. BB noted that the actual formula used seems to be about the same as used for GC, but HSV Exponential is better at preserving the saturation of colors in the highlights.

But you already knew all that.

Whichway
.


Michael314 ( ) posted Sun, 09 August 2009 at 11:50 AM

Quote -
But you already knew all that.

Hi,
of course. That's why I asked 🆒 
Thanks a lot for the explanation. So, tone mapping is just half of the fun, and if I want to use it, I have to apply reverse GC on all my textures and fixed color nodes, or the image will be overexposed :mad: . That will be much more complicated than the "GC" option PoserPro, that one was simple to use.
I can still hope for real GC in a P8 service release.

Best regards,
    Michael


Lucifer_The_Dark ( ) posted Sun, 09 August 2009 at 12:27 PM

I didn't, that's why I'm keeping quiet till I get time to do some proper reading up on this. :D

Windows 7 64Bit
Poser Pro 2010 SR1


IsaoShi ( ) posted Sun, 09 August 2009 at 12:33 PM · edited Sun, 09 August 2009 at 12:35 PM

Quote - So, tone mapping is just half of the fun, and if I want to use it, I have to apply reverse GC on all my textures and fixed color nodes, or the image will be overexposed :mad: . That will be much more complicated than the "GC" option PoserPro, that one was simple to use.

Well, TM HSV does only process the output render, but it is not the same as straight gamma correction. It corrects the image in a way that (somehow) approximates the anti-GC of incoming colours as well. That's what I meant when I said it's an approximation for full GC. In other words, if you are going to anti-GC incoming colours, then GC the output, and don't use TM HSV.  (This is my understanding of the long discussion thread, and the words from the master himself, on the subject).

Quote - I can still hope for real GC in a P8 service release.

I wouldn't waste any wishes! :O)
It will be in Poser Pro 2010.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)


bantha ( ) posted Sun, 09 August 2009 at 1:49 PM · edited Sun, 09 August 2009 at 1:50 PM

 You can still use GC in Poser 8, if you do it with shaders. You could do it your own way or use the Wacros in my Freestuff to change a shader in a GC-Shader. I haven't tested them with P8 up to now, but from what I know it should work.

For most people, GC too complicated because the incoming textures must be changed too. Tone mapping with HSV brings very similar results, but without changing the textures and materials, if I did not get something seriously wrong. I haven't tone any "final" renders with P8, but from what I've seen up to now, HSV set to 2.2 works for me.


A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori


operaguy ( ) posted Sun, 09 August 2009 at 2:02 PM

On the output side, one feature Poser8 lacks over pro is saving out to OpenEXR format, which then allows you to open the file in Photoshop in 32-bit editing mode. You can then effect not only gamma correction but subtlties of exposure into the color channels.

I always feel better having deep control in PS rather that in the render output itself, since obviously you have to render each time you tweak a setting in the render app whereas having the editing power of Photoshop on the color channel level to tweak instantly....well that is so much better.

Poser8 is good, but I won't get too thrilled until in possession of PoserPro2010 with OpenEXR format.

::::: Opera :::::


bagginsbill ( ) posted Sun, 09 August 2009 at 4:11 PM

Quote - > Quote -

But you already knew all that.

Hi,
of course. That's why I asked 🆒 
Thanks a lot for the explanation. So, tone mapping is just half of the fun, and if I want to use it, I have to apply reverse GC on all my textures and fixed color nodes, or the image will be overexposed :mad: . That will be much more complicated than the "GC" option PoserPro, that one was simple to use.
I can still hope for real GC in a P8 service release.

Best regards,
    Michael

No No No. Please don't restate things with a different bias or slant.

What you just said is only true for Exponential Tone Mapping.

HSV Exponential is different, and does not need any input compensation.

I was clear about this in my original post. You're going to confuse the hell out of everybody putting things in your own words.

I wish Rendo would just put the exact correct information in a sticky.

Somebody find the link to my post about  this please - I don't have time.


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)


bagginsbill ( ) posted Sun, 09 August 2009 at 4:13 PM

Quote - > Quote - 4. Poser 8 includes Tone Mapping with an option for HSV Exponential. This is an approximation to 'proper' input and output gamma correction.

Poser 8's Tone Mapping only approximates output GC. It does not touch input. This is not actually the right way to deal with GC, but it is a simple, sloppy approximation. Besides, SM documents Tone Mapping as a mechanism to compress the highlights, not expand the shadows. BB noted that the actual formula used seems to be about the same as used for GC, but HSV Exponential is better at preserving the saturation of colors in the highlights.

But you already knew all that.

Whichway
.

Tone mapping was invented for the purpose of compressing high-dynamic range content (HDRI) into limited color space.

Being mindful of how the the sRGB color space actually works, it has some element of exponential built in - can't be avoided.

The published math formula looks very different from the simple GC formula, but when I transform it, it's pretty much the same thing.


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)


ice-boy ( ) posted Sun, 09 August 2009 at 4:23 PM

yes. like if you want to use a HDRI image as a background. its darker. so you need to make it brighter.

right?


Whichway ( ) posted Sun, 09 August 2009 at 4:36 PM

My apologies if I've just added to the confusion; that, of course, was not my intent. But I suspect it is part of the reason SM only puts it into the Pro version. It confuses the daylights out of most of their regular users.

Whichway


bantha ( ) posted Mon, 10 August 2009 at 4:18 AM


A ship in port is safe; but that is not what ships are built for.
Sail out to sea and do new things.
-"Amazing Grace" Hopper

Avatar image of me done by Chidori


MistyLaraCarrara ( ) posted Wed, 12 August 2009 at 10:32 AM

Quote - From an artistic viewpoint, do what gives you results you like. From an accuracy viewpoint, you will always need it, at least until no one can remember what a CRT was.

Whichway

cathode ray teacup



♥ My Gallery Albums    ♥   My YT   ♥   Party in the CarrarArtists Forum  ♪♪ 10 years of Carrara forum ♥ My FreeStuff


RobynsVeil ( ) posted Thu, 24 December 2009 at 6:08 AM

Well, it was suggested I read up on tone-mapping. If there is a definitive answer to whether tone-mapping is to replace / do-away-with-the-need-to GC materials, I have yet to find it. So, to my simple mind, I still need to GC my materials.
And the question I've asked in other threads (which was ignored) I will ask again here, because it was asked at the beginning of this thread and the question was tap-danced around but not answered: why was not GC included in Poser 8 when the technology for Poser had been established in Poser Pro?
Marketing?
Makes Poser Pro worth the extra $150 upgrade price (for Base)?
Or was the code base for Poser 8 not conducive for adding GC?
What?

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks


bagginsbill ( ) posted Thu, 24 December 2009 at 8:43 AM · edited Thu, 24 December 2009 at 8:44 AM

Tone mapping is not to replace GC. I have shown how to abuse it to get something better than nothing, but it isn't GC. The purpose of TM is to transform values (potentially infinite values) into the unit-range 0 to 1 which is all that can be displayed on a computer monitor or piece of paper.

In so doing, it happens to make anything that starts in the unit-domain 0 to 1 curve upward, sort of like the GC curve does. But it isn't the same curve, and GC can go above 1 outside the unit-domain, but TM cannot.

The equation for GC (for gamma=k)

x ^ (1 / k)

The equation for TM (for arbitrary exponent, k)

1 - e ^ (-kx)

I'm using the "^" symbol for exponentiation. In the TM, e is the magical mathematical constant e, 2.71828... . But in this case, the value of e as a base is not important as it is possible to change to any other base value as long as we also make a corresponding adjustment in k, which itself is an arbitrary meaningless value. Put another way, no matter what base we change to, the new function is isomorphic with the original. But the GC and TM curves are not isomorphs - they do different things, even though at first glance they appear to have the same general shape, at least in the unit-domain.

As for why only Pro has it? It was a marketing decision. There is no technical barrier. In fact, it complicates things a bit to have any differences between Pro and regular Poser. Maintaining two different versions of the same code base is more complicated than maintaining only one version.


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)


Khai-J-Bach ( ) posted Thu, 24 December 2009 at 8:50 AM

note for the prevention of hair loss : do not GC Displacement Maps. they go funny and don't work properly..... (found this out the hard way....)



Michael314 ( ) posted Thu, 24 December 2009 at 9:09 AM

Hello,
well, we now have PPro 2010 beta, which includes indirect lighting AND GC.
This is a great plus! (And the beta runs more stable for me than the initial P8 release).

The only thing I need now is a script which sets the gamma value of displacement
and bump maps to 1.0, or the results with GC turned on might look weird.
(Try DAZ / RHS "Atonement" for example, the floor looks very weird with GC on.)
In cases where the same map is used for bump and color, an additional
node will be required.

If someone has such a script, please post. Otherwise I have to attempt such a thing
over the next days.

Best regards,
   Michael


Dizzi ( ) posted Thu, 24 December 2009 at 9:29 AM · edited Thu, 24 December 2009 at 9:30 AM

That script already ships with Poser (although it's way too much clicking): Scripts->MaterialMods->changeGamma. I intend to make a script that needs less clicking and allows more choices for that, so just wait ;-)



hborre ( ) posted Thu, 24 December 2009 at 9:47 AM

There should be a built-in script for converting gamma values to select material like PoserPro.  Unfortunately, IIRC, it is not selective how to apply it to nodes, but I'm just assuming because I never use the feature before.  In situations where is bump, normal, displacement maps are absent, I generate my own in either Photoshop, Gimp, or ShadowMap.  Generally, many material zones share the same image maps and node structures, and if you modify one, you could copy and paste into another. 


Michael314 ( ) posted Thu, 24 December 2009 at 10:08 AM

Quote - That script already ships with Poser (although it's way too much clicking): Scripts->MaterialMods->changeGamma. I intend to make a script that needs less clicking and allows more choices for that, so just wait ;-)

Hello,
thanks a lot for the fast reply! This is exactly what I need.
Since the script is provided with source, it is easy to create a "no-ask" version
of this one with the default answers as required as hardcoded input, that will
reduce the clicking.

Best regards,
   Michael


RobynsVeil ( ) posted Thu, 24 December 2009 at 3:42 PM

Quote - Tone mapping is not to replace GC. I have shown how to abuse it to get something better than nothing, but it isn't GC. The purpose of TM is to transform values (potentially infinite values) into the unit-range 0 to 1 which is all that can be displayed on a computer monitor or piece of paper.

So, tone-mapping (if I understand your reasoning correctly here, Bill) is more to bring HDRI into the 0 to 1 range so Poser can process them? If so, that makes sense. So, for what I want to be doing in Poser 7 (yes, haven't quite made the leap of faith) it would only apply for like SkyDome stuff and like that, nothing else.

Quote - As for why only Pro has it? It was a marketing decision. There is no technical barrier. In fact, it complicates things a bit to have any differences between Pro and regular Poser. Maintaining two different versions of the same code base is more complicated than maintaining only one version.

I was afraid you were going to say that. Oh well, that decision may work to my favour, actually. It forces me into the material room (like I have to be forced in) and look at shaders and wonder what was going on and fix things and add things and then GC and check and see if a script would do the job quicker for me (for hair, a script and VSS actually works faster!)

I do wish you and your lovely family a wonderful Christmas, Bill... you have added an incredible dimension to this passion of mine for which I will forever be in your debt.

Monterey/Mint21.x/Win10 - Blender3.x - PP11.3(cm) - Musescore3.6.2

Wir sind gewohnt, daß die Menschen verhöhnen was sie nicht verstehen
[it is clear that humans have contempt for that which they do not understand] 

Metaphor of Chooks


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