Features for deferred shading

What it says on the tin: a place to discuss proposed new features.
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Joined: Sat Jun 08, 2013 3:12 pm
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Re: Features for deferred shading

Post by RandomCitizen »

This thread was my first place to go when trying to find some news about ogre and deferred shading for seom time. As this might be the case for other users as well, I thought adding some information about the current state might be a good idea.
dark_sylinc wrote:
hydexon wrote:The only bad thing i find in UE3 only is still using the Forward Rendering pipeline, UE4 is completely deferred with physically-based shading system (when Ogre will have this?, will be cool!).

I'm actively working on PBS. Don't have screenshots to show yet.
However we won't back deferred shading (Ogre 2.0 will provide deferred shading examples, it will be much easier to setup for those interested).
Deferred Shading is a dead end by now, but it's still very much alive because you're seeing the culmination of many engines' work. DS is a dead end because of its extreme bandwidth requirement (no GPU in the market can push a 4k resolution using DS)
I'm working on Forward+ 2.5 solutions that eliminate the need of a Z-prepass. Although it has a few tradeoffs compared to DS (i.e. probably slightly slower at regular resolutions), it solves the bandwidth problem, the antialising problem, and the transparency problem.
http://www.ogre3d.org/forums/viewtopic. ... 15#p505090
Zonder wrote:
Crashy wrote:Dark_Sylinc, what do you mean by Forward +2.5 ?
I found a pdf with some info https://sites.google.com/site/takahiroh ... edirects=2
http://www.ogre3d.org/forums/viewtopic. ... 15#p505215

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Re: Features for deferred shading

Post by cloud »

I've been playing around with DS for a while now and I've discovered a top tip, rather than essentially duplicate the depth buffer after you render the gbuffer mrt (which is what the sample codes does via its flat ambient pass I think) you can use the mrt depth buffer. e.g.

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compositor DeferredShading/GBuffer
		texture mrt target_width target_height PF_FLOAT16_RGBA PF_FLOAT16_RGBA PF_FLOAT16_RGBA PF_FLOAT16_RGBA chain_scope
then in

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compositor DeferredShading/ShowLit
        texture scene target_width target_height PF_R8G8B8A8 no_fsaa
then anything you do with scene will be done on top of the depth buffer in mrt, note to reuse the depth buffer its size >= and fsaa that matter provided they match, you get to carry the depth buffer across.

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