Is free AA really worth it?
- Thread starter seismologist
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Laz8s, I think Xenos might actually bin the entire scene, just in a very different way than PowerVR.
From what I understand, the powervr architecture bins geometry (the output of vertex shaders) for frame N+1 while rendering frame N.
Xenos bins rendering commands (input to vertex shaders) which touch as yet unrendered tiles in the current frame.
In the PowerVR case, this means that each primitive passes through the vertex shader only once. On Xenos, it may have to processed multiple times. On the other hand, PowerVR has to bin transformed geometry, whereas the Xenos has practically zero binning overhead in comparison. This is because most primitives will be defined in terms of static vertex arrays/buffers/strips etc...
IMO this makes perfect sense given the tile size of Xenos and the UMA system of limited capacity/bandwidth (hopefully triangle count will be very large in comparison to PC games).
From what I understand, the powervr architecture bins geometry (the output of vertex shaders) for frame N+1 while rendering frame N.
Xenos bins rendering commands (input to vertex shaders) which touch as yet unrendered tiles in the current frame.
In the PowerVR case, this means that each primitive passes through the vertex shader only once. On Xenos, it may have to processed multiple times. On the other hand, PowerVR has to bin transformed geometry, whereas the Xenos has practically zero binning overhead in comparison. This is because most primitives will be defined in terms of static vertex arrays/buffers/strips etc...
IMO this makes perfect sense given the tile size of Xenos and the UMA system of limited capacity/bandwidth (hopefully triangle count will be very large in comparison to PC games).
Megadrive1988 said:
Not to mention that there's a lot of AA.
Aliasing artifacts are probably the result of low-precision motion blur. Almost all renderers but Pixar's Renderman take an 500-1000% speed hit with high quality motion blur because they'd have to render the geometry 5-10 times to interpolate its movement (PRMan takes, like, 150-200% at the worst because it cheats a lot - but it's a patented method AFAIK).
So when deadlines are tight, motion blur is one of the first things to get replaced with low quality image processing stuff...
richardpfeil
Newcomer
The input to the vertex shaders cannot be binned. The position of the vertex in screen space is unknown until the vertex shader is run. Binning worked on the PowerVR because all vertex Transform & Lighting was handled by the driver (calculated on the CPU). Binning on the Xenos can only happen after the vertex shader is run. Either the vertex shaders will have to run multiple times, or MEMEXPORT is used to store post processed vertices. Running the vertex shaders multiple times doesn't sound much like a less than 5% hit to me.
I'd love to know how this works. My guess is that the vertex shader output is assembled to triangles, and then tile coverage is calculated. The results are then sent two ways, out to memory, and also to the rasterizer for a Z only pass. Then the stored results are then re-sent (based on calculated coverage) for each tile.
The problem with this method is that the data written out to memory could be quite large (easily over 100MB) and would consume a lot of memory and bandwidth. For this to work there would need to be a good amount of compression going on.
I'd love to know how this works. My guess is that the vertex shader output is assembled to triangles, and then tile coverage is calculated. The results are then sent two ways, out to memory, and also to the rasterizer for a Z only pass. Then the stored results are then re-sent (based on calculated coverage) for each tile.
The problem with this method is that the data written out to memory could be quite large (easily over 100MB) and would consume a lot of memory and bandwidth. For this to work there would need to be a good amount of compression going on.
fouad said:fouad said:
Ok, excuse me ! I thought you want me to post here...
this is a xbox forum, every PS fanboys are TROLL, and go home
thx jvd...
If you want to post in a forum that is dedicated to one console I suggest you go and find one . If you want to speak out in favor of a troll then I suggest you relocated to another forum . Trolling is not permited . If you want to engaged or encourage trolling please leave now Verison
Guys, Please.
There are almost more locked threads than open ones in here, do we really need another one?
Get a grip for God's sake, don't you understand that posting like that only gets threads locked? How many more do you need to get the point?
If you have to post crap, don't post.
There are almost more locked threads than open ones in here, do we really need another one?
Get a grip for God's sake, don't you understand that posting like that only gets threads locked? How many more do you need to get the point?
If you have to post crap, don't post.
man, another low post trolll?
Perhaps it would be a good idea to not accept any new members for a while. Or even better make them answer a questionaire designed to weed out people like fouad before registering There has to be a way to prevent these people from registering just so they can troll.
Perhaps it would be a good idea to not accept any new members for a while. Or even better make them answer a questionaire designed to weed out people like fouad before registering
There has to be a way to prevent these people from registering just so they can troll.- Status