| megafenix said:
1.-multipass rendeinring as the name suggests requires the use of the pipeline multiple times for one work and single pass you use it one time so obviously that means less use of the ipeline to achieve a task, in the sdk information they tell us that 1080p or 720p can be done on a single pass. I woudnt call singl pass a old feature since was implemented on directx 8 and wasnt avalable before it
2.-For the deffered rendering i just provided the article about the limitations on 360 sicne they needed 12MB gbuffer and since they didnt have it in the second article is explained that they had to use gpu parallelism and+cpu while the ps3 had to use 5spus out of the 8 that ps3 has(one spu is for the SO); doing it that way they can achieve the technique but also consumes large amount of rendering power, maybe still less than forward rendering but perfromance still wont be as good if they had enough memory bandwidth to do it the normal way. Wii U has enough bandwidth to sore triple framebuffers on 10.8MB and for the gbuffer would be about 8.64MB, with that in mind its clear that the deffered rendering on wii u will not take to much shader power as it took in last generation consoles and also will be better than using forward rendering, i wont deny that amost 9MB for the gbuffer is a lot bandwidth consumption, but seeing that triple frembuffers of 720p are just 10.8MB that still leaves edram room for other things and by trading bandwidth we can save up a lot shader power for other rendering purposes yes is true that deffered rendering is multipass, but compared to forward rendering requires less passes, in fact only requires two passes while forward rendering would require that or more for the complex material/light combination
3.-As for the tiled textures, well, i just mentioned that sicne shinen is using 4k-8k textures and even with BC1 compression they are still to bif to fit on texture memory or in the edram its possible they devided the textures into tiles so that they could fit them in texture memory; i am not sure if they are using it or not but the first image of fast racing neo seems to tell us they are indeed using texture tiles for the terrain at least |
1. Again that is multi texturing, which is a different thing. And DirectX 8 is 14+ years old, that is ancient in the tech world.
2. Did you even read what you posted? Deferred rendering is a multi pass system. It's not the same as multi pass on a forward renderer tho. On a forward renderer you have to process each fragment per light in the scene. The problem is that for each pass you have to re-process the geometry which adds up. Deferred shading solves this issue by decoupling the geometry and the lighting to seperate passes. On the first pass of a deferred shader geometry, normals, and materials for each surface are rendered into the geometry buffer (G-buffer) as a series of textures (called Multiple Render Targets). After this, a pixel shader computes the direct and indirect lighting at each pixel using the information of the texture buffers, in screen space.
3. Ah you a confused due to the use of the word tiling. Tiled textures is an old slang term used to describe using a single repeated texture on a large surface. There are both technical and production reasons for doing this, mainly there is a limit o how big a texture the hardware can support and large high res textures take up a lot of memory. So the problem comes in when you have a very large area to cover. Then you have two options streatch a single large texture 8k X 8K is probably the max, this probably end up looking terrible and low res. The other is to use several textures on the same object. The problem with this is that using a lot of different textures is expensive on memory and processing as well as production (you have to make a lot of textures and make sure they fit together). To get around this devs will often use a single texture and just repeat it lots of times, you can see the downside of this in that screen as you get that repeated pattern. And just about every game does it.
Splitting up large textures into smaller peices can be called tile bassed texturing yes but that is a different technique altogether. AMD called it Partially Resident Textures, however MS called it Tiled Resources when they implemented it in DX11.2. id also used a software version of the technique for RAGE they called Mega Textures. The main advantage of Tiled Resources is that you bypass the technical limitations on texture size by splitting large textures into smaller chunks and loading each chunk in as needed instead of the full texture. As shown in Rage this actualy means you don't need to use repeated textures as long as you have the production capacity to create unique textures for every surface.
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