Thread: RE: Gamma=1 rendering engine( Was RE: [Algorithms] Mip-map genera tion)
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From: Jason M. <Ja...@at...> - 2004-09-29 16:29:35
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Indeed, this is cheap. Note also that future hardware will = eventually get this right by converting from 2.2 gamma to linear space prior to = texture filtering, unlike current hardware or a manual "squaring" in the pixel shader. -Jason -----Original Message----- From: Tom Forsyth [mailto:tom...@ee...]=20 Sent: Tuesday, September 28, 2004 9:40 PM To: gda...@li... Subject: RE: Gamma=3D1 rendering engine( Was RE: [Algorithms] Mip-map generation) SRGBTEXTURE is pretty cheap - not sure it's actually free on all cards, = but it's not a big cost. But if you have hardware that does it, then you = don't need to be doing any work in the shader - everything inside the shader should be in linear space. TomF. > -----Original Message----- > From: gda...@li... > [mailto:gda...@li...] On=20 > Behalf Of Jonathan Blow > Sent: 28 September 2004 20:26 > To: gda...@li... > Subject: Re: Gamma=3D1 rendering engine( Was RE: [Algorithms]=20 > Mip-map generation) >=20 >=20 > But you then wouldn't be able to use SRGBTEXTURE, because that has a > hardcoded gamma of 2.2, so you'd kind of be hosing your textures. So = > instead you would need to spend a pixel shader instruction=20 > squaring the=20 > texture color every time you read from a texture. Actually not a big = > deal on modern cards, and it may even be the same speed (I=20 > don't know if=20 > srgbtexture is generally "free" or just a hidden cost that=20 > doesn't count=20 > toward your instruction limit). >=20 > Anyway, the cost of that last full-screen pass is so low that > it's not=20 > even in the realm of things I am thinking about optimizing right now. >=20 >=20 > Tom Forsyth wrote: >=20 > >>(Provided that sqrt() > >>is faster than pow() in a pixel shader, I really don't know that). > >> =20 > >> > > > >Yes, it is. > > > >TomF. > > > > =20 > > > >>-----Original Message----- > >>From: gda...@li... > >>[mailto:gda...@li...] On=20 > >>Behalf Of Christian Sch=FCler > >>Sent: 28 September 2004 08:35 > >>To: gda...@li... > >>Subject: RE: Gamma=3D1 rendering engine( Was RE: [Algorithms]=20 > >>Mip-map generation) > >> > >> > >> > >>I would recommend to run sqrt() for the gamma phase and save > >>yourself the last .2 of the exponent. (Provided that sqrt()=20 > >>is faster than pow() in a pixel shader, I really don't know that). > >> > >> > >>-----Original Message----- > >>From: gda...@li... > >>[mailto:gda...@li...] On=20 > >>Behalf Of Jonathan Blow > >>Sent: Monday, September 27, 2004 11:39 PM > >>To: gda...@li... > >>Subject: Re: Gamma=3D1 rendering engine( Was RE: [Algorithms]=20 > >>Mip-map generation) > >> > >> > >> > >> =20 > >> > >>>So, are you noticing any real benefits? I know the theory, > it's been > >>>talked about here, but do you notice a real increase in the image > >>>quality? Are you able to recreate the same scenes in a=20 > 'traditional' > >>>renderer? > >>>=20 > >>> > >>> =20 > >>> > >>Haven't gotten that far yet. I think there is an increase in > >>how much=20 > >>the scene makes visual sense to your brain, but it is kind of=20 > >>subtle. =20 > >>For example, you don't have the "lights get dimmer as you move them = > >>toward the wall" problem any more, and the cos(theta) curve=20 > >>for diffuse=20 > >>lighting is sharper, like it is in real life, instead of the softer = > >>thing you get in gamma=3D2.2 or whatever.=20 > >> > >>I have a lot of eventual plans that pretty much want HDR and > >>gamma=3D1 in=20 > >>order to be of any kind of real quality (like, doing "shadows" of=20 > >>translucent objects onto the ground by casting negative light=20 > >>around...=20 > >>umm I dunno if there is any official graphics term for that). Plus = > >>effects like bloom are much better, but I am not doing those=20 > >>right now. > >> > >> =20 > >> > >>>Also, I have to assume you are 'applying gama'(not sure > what the term > >>>is) at the end of the scene? > >>> > >>> =20 > >>> > >>Yeah, everything gets rendered into a temporary surface, > then as the > >>final step that gets copied into the back buffer with a shader that > >>basically runs pow() on every pixel. (Which is also where=20 > >>you would do=20 > >>your effects like bloom and depth of field and whatever,=20 > but I am not > >>doing those right now). > >> > >> > >> > >> > >>------------------------------------------------------- > >>This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one > >>of 170 Project Admins to receive an Apple iPod Mini FREE for=20 > >>your judgement on who ports your project to Linux PPC the=20 > >>best. Sponsored by IBM. > >>Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php=20 > >>_______________________________________________ > >>GDAlgorithms-list mailing list=20 > GDA...@li... > >>https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > >>Archives: = http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 > >> > >> > >>------------------------------------------------------- > >>This SF.Net email is sponsored by: YOU BE THE JUDGE. Be one of 170=20 > >>Project Admins to receive an Apple iPod Mini FREE for your = judgement=20 > >>on who ports your project to Linux PPC the best. Sponsored by IBM. > >>Deadline: Sept. 24. Go here: http://sf.net/ppc_contest.php > >>_______________________________________________ > >>GDAlgorithms-list mailing list > >>GDA...@li... > >>https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > >>Archives: > >>http://sourceforge.net/mailarchive/forum.php?forum_ida88 > >> > >> =20 > >> > > > > > > > >------------------------------------------------------- > >This SF.net email is sponsored by: IT Product Guide on > ITManagersJournal > >Use IT products in your business? Tell us what you think of > them. Give us > >Your Opinions, Get Free ThinkGeek Gift Certificates! Click > to find out more > >http://productguide.itmanagersjournal.com/guidepromo.tmpl > >_______________________________________________ > >GDAlgorithms-list mailing list=20 > >GDA...@li... > >https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > >Archives: http://sourceforge.net/mailarchive/forum.php?forum_ida88 > > > > =20 > > >=20 >=20 >=20 > ------------------------------------------------------- > This SF.net email is sponsored by: IT Product Guide on > ITManagersJournal > Use IT products in your business? Tell us what you think of=20 > them. Give us > Your Opinions, Get Free ThinkGeek Gift Certificates! Click to=20 > find out more > http://productguide.itmanagersjournal.com/guidepromo.tmpl > _______________________________________________ > GDAlgorithms-list mailing list > GDA...@li... > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_ida88 >=20 ------------------------------------------------------- This SF.net email is sponsored by: IT Product Guide on = ITManagersJournal Use IT products in your business? Tell us what you think of them. Give = us Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out = more http://productguide.itmanagersjournal.com/guidepromo.tmpl _______________________________________________ GDAlgorithms-list mailing list GDA...@li... https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list Archives: http://sourceforge.net/mailarchive/forum.php?forum_ida88 |
From: Charles B. <cb...@cb...> - 2004-09-29 17:03:52
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So, who's going to actually calibrate all their artists' monitors & workspaces to gamma 2.2 ? ;) At 12:33 PM 9/29/2004 -0400, you wrote: > Indeed, this is cheap. Note also that future hardware will eventually > get this right by converting from 2.2 gamma to linear space prior to > texture filtering, unlike current hardware or a manual "squaring" in the > pixel shader. ---------------------------------------------------- Charles Bloom email "cb" http://www.cbloom.com |
From: Emanuele S. <in...@fo...> - 2004-09-29 17:36:36
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http://www.colorwizzard.com/index.html ...let your artists do it by themselves! ;))) Best, Emanuele Salvucci Maya|Lightwave Game Technical Artist Lscript developer www.forwardgames.com ema...@fo... "#3. He causes things to look different so it would appear time has = passed." -------------------------------------------------------------------------= ------- ----- Original Message -----=20 From: "Charles Bloom" <cb...@cb...> To: <gda...@li...> Sent: Wednesday, September 29, 2004 7:03 PM Subject: RE: Gamma=3D1 rendering engine( Was RE: [Algorithms] Mip-map = genera tion) >=20 > So, who's going to actually calibrate all their artists' monitors &=20 > workspaces to gamma 2.2 ? ;) >=20 > At 12:33 PM 9/29/2004 -0400, you wrote: >=20 > > Indeed, this is cheap. Note also that future hardware will = eventually=20 > > get this right by converting from 2.2 gamma to linear space prior to = > > texture filtering, unlike current hardware or a manual "squaring" in = the=20 > > pixel shader. >=20 > ---------------------------------------------------- > Charles Bloom email "cb" http://www.cbloom.com >=20 >=20 >=20 > ------------------------------------------------------- > This SF.net email is sponsored by: IT Product Guide on = ITManagersJournal > Use IT products in your business? Tell us what you think of them. Give = us > Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out = more > http://productguide.itmanagersjournal.com/guidepromo.tmpl > _______________________________________________ > GDAlgorithms-list mailing list > GDA...@li... > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 >=20 >=20 |
From: Alex M. <am...@cs...> - 2004-09-29 18:28:24
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There are devices and such that you can get to do accurate color-correct calibrations. All the artists' monitors here at Pixar are carefully calibrated in this fashion. And I'd bet that we've got a lot more artists than most game companies. It's definitely a doable thing. Alex >So, who's going to actually calibrate all their artists' monitors & >workspaces to gamma 2.2 ? ;) > >At 12:33 PM 9/29/2004 -0400, you wrote: > >> Indeed, this is cheap. Note also that future hardware will eventually >>get this right by converting from 2.2 gamma to linear space prior to >>texture filtering, unlike current hardware or a manual "squaring" in the >>pixel shader. > >---------------------------------------------------- >Charles Bloom email "cb" http://www.cbloom.com > > > >------------------------------------------------------- >This SF.net email is sponsored by: IT Product Guide on ITManagersJournal >Use IT products in your business? Tell us what you think of them. Give us >Your Opinions, Get Free ThinkGeek Gift Certificates! Click to find out more >http://productguide.itmanagersjournal.com/guidepromo.tmpl >_______________________________________________ >GDAlgorithms-list mailing list >GDA...@li... >https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list >Archives: >http://sourceforge.net/mailarchive/forum.php?forum_id=6188 |
From: Simon O'C. <si...@sc...> - 2004-09-29 19:24:50
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Though surely to be close to accurate, you'd need to re-calibrate on an hourly basis to account for changes in ambient light levels in the office - unless you're based somewhere with bright sun all year round or force the artists to work in a black room with no windows ;o) I suppose the best thing to do is educate the artists about *how and why* the setting of their monitor and accounting for office lighting will affect the consistency and quality of their art when seen in the game. Working together also reduces the number of "the engine is making my stuff look really dark" complaints. > -----Original Message----- > From: gda...@li... > [mailto:gda...@li...] On > Behalf Of Alex Mohr > Sent: 29 September 2004 19:28 > To: gda...@li... > Subject: Re: Gamma=1 rendering engine( Was RE: [Algorithms] > Mip-map genera tion) > > There are devices and such that you can get to do accurate > color-correct calibrations. All the artists' monitors here > at Pixar are carefully calibrated in this fashion. And I'd > bet that we've got a lot more artists than most game > companies. It's definitely a doable thing. > > Alex > > > >So, who's going to actually calibrate all their artists' monitors & > >workspaces to gamma 2.2 ? ;) > > > >At 12:33 PM 9/29/2004 -0400, you wrote: > > > >> Indeed, this is cheap. Note also that future hardware will > >>eventually get this right by converting from 2.2 gamma to > linear space > >>prior to texture filtering, unlike current hardware or a manual > >>"squaring" in the pixel shader. > > > >---------------------------------------------------- > >Charles Bloom email "cb" http://www.cbloom.com > > > > > > > >------------------------------------------------------- > >This SF.net email is sponsored by: IT Product Guide on > >ITManagersJournal Use IT products in your business? Tell us what you > >think of them. Give us Your Opinions, Get Free ThinkGeek Gift > >Certificates! Click to find out more > >http://productguide.itmanagersjournal.com/guidepromo.tmpl > >_______________________________________________ > >GDAlgorithms-list mailing list > >GDA...@li... > >https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > >Archives: > >http://sourceforge.net/mailarchive/forum.php?forum_id=6188 > > > ------------------------------------------------------- > This SF.net email is sponsored by: IT Product Guide on > ITManagersJournal Use IT products in your business? Tell us > what you think of them. Give us Your Opinions, Get Free > ThinkGeek Gift Certificates! Click to find out more > http://productguide.itmanagersjournal.com/guidepromo.tmpl > _______________________________________________ > GDAlgorithms-list mailing list > GDA...@li... > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_id=6188 > > --- > Incoming mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.770 / Virus Database: 517 - Release Date: 27/09/2004 > > --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.770 / Virus Database: 517 - Release Date: 27/09/2004 |
From: Alex M. <am...@cs...> - 2004-09-29 21:23:43
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>Though surely to be close to accurate, you'd need to re-calibrate on an >hourly basis to account for changes in ambient light levels in the office - >unless you're based somewhere with bright sun all year round or force the >artists to work in a black room with no windows ;o) This turns out to be a non-issue because... >I suppose the best thing to do is educate the artists about *how and why* >the setting of their monitor and accounting for office lighting will affect >the consistency and quality of their art when seen in the game. Working >together also reduces the number of "the engine is making my stuff look >really dark" complaints. Everyone here for whom color perception matters knows how the office lighting (and even the color of the plastic bezel of your monitor) affects perception. If not in a scientific way, certainly in an intuitive way. They exercise tight control over the lighting and wall colors in their offices, and yes, most of these folks have windowless offices with gray or some other neutral color walls and low lighting. The calibration holds up pretty well. Alex |