Comments on: A conceptually simple(r) way to derive exponential shadow maps + sample code http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/ Mon, 12 Oct 2009 22:17:15 +0000 http://wordpress.com/ hourly 1 By: Marco Salvi http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-229 Marco Salvi Tue, 16 Jun 2009 06:01:09 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-229 Free hosting web sites never work as advertised, I purchased some space and the link to ShaderX6 code should be working now. Free hosting web sites never work as advertised, I purchased some space and the link to ShaderX6 code should be working now.

]]> By: Jan Helleman http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-223 Jan Helleman Wed, 10 Jun 2009 01:44:39 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-223 can any reupload the shaderX6 code, or send it to me? slaaitjuh [AT] gmail [dot] com can any reupload the shaderX6 code, or send it to me? slaaitjuh [AT] gmail [dot] com

]]> By: Marco Salvi http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-211 Marco Salvi Wed, 27 May 2009 08:14:56 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-211 Zirka, I uploaded the ShaderX6 material to another website and I have update the old link with a new one. Marco Zirka,

I uploaded the ShaderX6 material to another website and I have update the old link with a new one.

Marco

]]> By: Zirka http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-209 Zirka Tue, 26 May 2009 18:11:01 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-209 Hi Marco! ESM definitely looks like a very useful technique, and after implementing VSM with cascades, the results in my complex scene were not as good as I need, so I started looking into ESM. I was hoping to check out a demo of ESM from you but the link you posted for the correct ShaderX6 demo is no longer functional. Could you repost it? Thanks a bunch! Hi Marco!

ESM definitely looks like a very useful technique, and after implementing VSM with cascades, the results in my complex scene were not as good as I need, so I started looking into ESM. I was hoping to check out a demo of ESM from you but the link you posted for the correct ShaderX6 demo is no longer functional. Could you repost it?

Thanks a bunch!

]]> By: Viik http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-174 Viik Wed, 10 Dec 2008 17:13:58 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-174 I'm taking my words back, everything became fine right after I switched back to back face culling, completely forgot about that. I'm switching from VSM to ESM for now, thank you for you great research! I’m taking my words back, everything became fine right after I switched back to back face culling, completely forgot about that. I’m switching from VSM to ESM for now, thank you for you great research!

]]> By: Viik http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-173 Viik Mon, 08 Dec 2008 13:16:09 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-173 Agree with Damsku - it's definately nice that we are not getting penubra from one caster bleeding to another one, like in VSM, but caster contact point is definately shaded unproperly. Look at this screenshots: http://i6.photobucket.com/albums/y245/ViiKzzz/Exponentialshadowmap.jpg In both cases i'm using linear depth, gaussian separable 5x5 tap blur with Ln filter and depth is multiplayed by 10 (with smaller value even bigger amount of over darkening factro is needed). I think some thing really important is missing in FX file. Agree with Damsku – it’s definately nice that we are not getting penubra from one caster bleeding to another one, like in VSM, but caster contact point is definately shaded unproperly. Look at this screenshots:
http://i6.photobucket.com/albums/y245/ViiKzzz/Exponentialshadowmap.jpg
In both cases i’m using linear depth, gaussian separable 5×5 tap blur with Ln filter and depth is multiplayed by 10 (with smaller value even bigger amount of over darkening factro is needed). I think some thing really important is missing in FX file.

]]> By: realtimecollisiondetection.net - the blog » Posts and links you should have read http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-158 realtimecollisiondetection.net - the blog » Posts and links you should have read Tue, 02 Sep 2008 15:34:27 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-158 [...] summary (of PCSS, PSSM, and screen-size shadow masks/accumulation buffers) and Marco Salvi’s twist on ESMs and his faster PCF post. Marco also talked about shadows (based off this teaser) at GDC as part of [...] [...] summary (of PCSS, PSSM, and screen-size shadow masks/accumulation buffers) and Marco Salvi’s twist on ESMs and his faster PCF post. Marco also talked about shadows (based off this teaser) at GDC as part of [...]

]]> By: Andrew Lauritzen http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-136 Andrew Lauritzen Fri, 20 Jun 2008 01:32:39 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-136 Yep fair enough with respect to the trade-offs. I think EVSM will be pretty interesting in the 1-2 year sort of time frame for games, but it's certainly a bit resource-heavy for games right now. As an aside, 32-bit float formats *are* filterable in DX9 if your card supports it. They just aren't guaranteed to be... but if you have a G80+ or R600+ you're laughin' :) Yep fair enough with respect to the trade-offs. I think EVSM will be pretty interesting in the 1-2 year sort of time frame for games, but it’s certainly a bit resource-heavy for games right now.

As an aside, 32-bit float formats *are* filterable in DX9 if your card supports it. They just aren’t guaranteed to be… but if you have a G80+ or R600+ you’re laughin’ :)

]]> By: Damsku http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-135 Damsku Thu, 19 Jun 2008 08:20:57 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-135 Thank you Andrew. I did dig in EVSM already. But it seems the requirements are more heavy in the end, precision wise for sure... If I could use R32F targets and if they were filterable in dx9. I would be using EVSM, the result was pretty promising :) Concerning the ESM, my major issue is that I cannot get the shadows to be as dark at the caster contact point as far from the caster. Which forces me to use a large overdarkening factor/depth scale combinaison and hereby kills part of the softness. It visually just looks like the power function in VSM which reduce light bleeding at the cost of edge softness. Thank you Andrew. I did dig in EVSM already. But it seems the requirements are more heavy in the end, precision wise for sure… If I could use R32F targets and if they were filterable in dx9. I would be using EVSM, the result was pretty promising :)

Concerning the ESM, my major issue is that I cannot get the shadows to be as dark at the caster contact point as far from the caster. Which forces me to use a large overdarkening factor/depth scale combinaison and hereby kills part of the softness. It visually just looks like the power function in VSM which reduce light bleeding at the cost of edge softness.

]]> By: Andrew Lauritzen http://pixelstoomany.wordpress.com/2008/06/12/a-conceptually-simpler-way-to-derive-exponential-shadow-maps-sample-code/#comment-134 Andrew Lauritzen Thu, 19 Jun 2008 03:35:07 +0000 http://pixelstoomany.wordpress.com/?p=17#comment-134 Just wanted to note that indeed you can combine ESM and VSM -> there's some information on "exponential variance shadow maps" at the end of the layered VSM paper and more info in the Beyond3D thread. In general it works very well (as you correctly speculated) although uses more memory than stock ESMs. You can also use"layering" with ESM if you wish - i.e. partition the light-space depth range into layers and use a single component for an ESM for each. Reconstruction can just select the proper one. It's pretty cheap on performance although of course it also uses more memory and probably doesn't scale as well in memory as something more clever. To that end, I know Marco's been fiddling with some more ideas... ready to give away any hints on that stuff yet Marco? :) Just wanted to note that indeed you can combine ESM and VSM -> there’s some information on “exponential variance shadow maps” at the end of the layered VSM paper and more info in the Beyond3D thread. In general it works very well (as you correctly speculated) although uses more memory than stock ESMs.

You can also use”layering” with ESM if you wish – i.e. partition the light-space depth range into layers and use a single component for an ESM for each. Reconstruction can just select the proper one. It’s pretty cheap on performance although of course it also uses more memory and probably doesn’t scale as well in memory as something more clever.

To that end, I know Marco’s been fiddling with some more ideas… ready to give away any hints on that stuff yet Marco? :)

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