upnorthsox
Veteran
But RSX has no problem reading/writing from XDR so in that case you just run it in XDR.
Actually IIRC, Cell has little problem writing to the GDDR3 but you don't want to read from there.
The Game Technology discussion thread *Read first post before posting*
- Thread starter Shifty Geezer
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But RSX has no problem reading/writing from XDR so in that case you just run it in XDR.
Actually IIRC, Cell has little problem writing to the GDDR3 but you don't want to read from there.
Panajev2001a
Veteran
4 GB/s does not seem == no writing issues, it is not that slow compared to PCI-Express though, I'll give you that.
Being able to read from GDDR3 at decent speed would allow you to read directly from SPE's and store the data in their LS and then write from there saving quite a bit of XDR bandwidth compared to just writing into XDR and reading from there using RSX.
Because it's a bandwith problem, not a computational one.
I'd think the real problem is that rasterization is done on RSX not Cell, thus it makes no sense to use Cell for that alphablending.
For other kinds of alpha blending, full screen stuff etc, I'm sure Cell is more than fine especially if you are doing other pixel stuff on Cell already.
For other kinds of alpha blending, full screen stuff etc, I'm sure Cell is more than fine especially if you are doing other pixel stuff on Cell already.
You could potentially offload some alpha belnded effects, like smoke, to a Cell rasteriser that composites what it produces with the RSX rendered main scene. Handling typical alpha issues like foliage, Cell wouldn't really fly.
marcus_rocks
Newcomer
How about why alpha blending causes overdraw? What could be a possible fix for the PS3? As far as I understand this is a technical forum.
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The main issue we have been raising here is that of the bandwidth limitation with alpha transparencies and overdraw. Reading and writing the pixels to the framebuffers implies data transfers @ x-bits per pixel. Overdraw compounds things with further accesses and data traversal due to an increase in need to compute the proper updated pixels with overlapped effects that cannot be culled (because they're translucent). The math itself is fairly trivial.
addition:
Mind you, pixel fillrate is still finite, but reducing the resolution of the alpha effects will alleviate both fillrate and bandwidth consumption. MSAA can help here too with sub-sampling or some other upscaling filter (bilinear/bicubic) so the effects look somewhat smoother on-screen, but detail is still lost.
Well if something is transparent, you can't really skip rendering stuff that's behind it... A completely new approach to render such effects is what the PS3 could use, but there aren't any feasible alternatives for it in realtime rendering.
Which is exactly what Joker's talking about... so we're full circle, finally.
That's the reason why devices with fast Local-storage are good at it (be they GPUs or CPUs) - so you're arguing for Cell, not against it.Laa-Yosh said:
The issue is that rasterization becomes a computational problem if you move it to SPUs, so viability varies a lot case by case.
Vast majority of volume/particle effects are devoid of any real detail to begin with, regardless of rendering resolution.AlStrong said:
Anyway, lower-res rendering of particle transparencies was popular last gen already, even on PS2 with all its fillrate - people on forums just weren't obsessive with counting pixels then, so it went unnoticed.
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Indeed.
And dynamic res too! Riddick and Max Payne 2 (Xbox) were ones that I noticed. Riddick to keep the framerate up with all those shadows... Max Payne 2 lowered the res with the bullet time. Very pixelated.Anyway, lower-res rendering of particle transparencies was popular last gen already, even on PS2 with all its fillrate - people on forums just weren't obsessive with counting pixels then, so it went unnoticed.
Indeed.
And dynamic res too! Riddick and Max Payne 2 (Xbox) were ones that I noticed. Riddick to keep the framerate up with all those shadows... Max Payne 2 lowered the res with the bullet time. Very pixelated.
Riddick to. The underground mine had jaggies the size of biscuits.
Please put my response in context and read the post I've replied to...
Since it isn't out yet most screenshots are PR right now so I think the best way to see it is to watch the videos especially the falling clocktower video. Also almost all of the enemies turn transparent when she does the button mashing attacks. You can't go through that portion of the game without seeing it...at least I can't. Oh and the 360 version is available for people who have a Japanese Xbox Live silver account.
http://i38.tinypic.com/jhbtwx.png
Found a PR shot.
http://scrawlfx.com/gallery/albums/bayonetta/october-22-2009/Bayonetta_2009_10-22-09_21.jpg
I know that it is a crappy screen shot I don't have HD capture equipment but you see that transparent gold, that is one of the angel enemies and I have a video full of it...just without any sound. But Joker is right there are enemies bigger than this that turn transparet and in many cases several of them at a time.
Edit because I don't think you guys can see it but that monter or angel enemy is actually taking up almost half of the freakin screen.
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Billy Idol
Legend
Thanks! It was a long read, but I think I got a good idea to the answer of my "speculating" questionGeneral reminders are good to have from time to time.
Getting back to a previous issue, here's a very nice tech demo / benchmark that features DX11 tesselation and displacement mapping.
http://unigine.com/press-releases/091022-heaven_benchmark/
Couple of notes:
They should really dial the bloom and DOF back.
They should also note that tesselation alone is not enough for this detail, they're using displacement maps on top of it (extra memory cost! although only 16 bits per pixel is needed).
Very high quality artwork there, and the dragon was a good choice to showcase the tech. I'm not that much of an expert but shadows look very high quality too, and it seems to use some kind of deferred lighting for the nighttime scenes; and looks like some nice AO is there, too.
Now this runs on a DX11 PC, and I absolutely don't expect any current gen console to have a reasonable implementation of the tech, the performance is not there IMHO. So it's more like a glimpse of the future, now that the tech finally seems to get ironed out, it should really become a standard for the next PS/Xbox.
I also think that the art pipeline may be able to get away with a relatively small upgrade - highres source models will still be created in Zbrush/Mudbox, textures don't need any change, it's just that in addition to the normal map (which will have to remain!) the tools will need to generate a displacement map; and the modelers will also have to get preview tools for the tesselation part.
Level creation might end up a bigger problem though... particularly collision detection with the scale of displacement in this demo. Sometimes those bricks move around as much as 20-30cm, that'll be a problem. Not to mention raycasting around the scene; view-dependent methods can confuse the system and more polygons mean more calculations for the AI. Interesting problem for sure.
Anyway, it's finally a very good demonstration of what to expect.
http://unigine.com/press-releases/091022-heaven_benchmark/
Couple of notes:
They should really dial the bloom and DOF back.
They should also note that tesselation alone is not enough for this detail, they're using displacement maps on top of it (extra memory cost! although only 16 bits per pixel is needed).
Very high quality artwork there, and the dragon was a good choice to showcase the tech. I'm not that much of an expert but shadows look very high quality too, and it seems to use some kind of deferred lighting for the nighttime scenes; and looks like some nice AO is there, too.
Now this runs on a DX11 PC, and I absolutely don't expect any current gen console to have a reasonable implementation of the tech, the performance is not there IMHO. So it's more like a glimpse of the future, now that the tech finally seems to get ironed out, it should really become a standard for the next PS/Xbox.
I also think that the art pipeline may be able to get away with a relatively small upgrade - highres source models will still be created in Zbrush/Mudbox, textures don't need any change, it's just that in addition to the normal map (which will have to remain!) the tools will need to generate a displacement map; and the modelers will also have to get preview tools for the tesselation part.
Level creation might end up a bigger problem though... particularly collision detection with the scale of displacement in this demo. Sometimes those bricks move around as much as 20-30cm, that'll be a problem. Not to mention raycasting around the scene; view-dependent methods can confuse the system and more polygons mean more calculations for the AI. Interesting problem for sure.
Anyway, it's finally a very good demonstration of what to expect.
To be honest I'm not so sure even to bayonetta full res buffers. From what I seen there aren't so drastically differences between dmc 4 & bayonetta in appearance.You're sure they're using full res-buffers in DMC4The other Framework Engine games did not... RE5/LP1/LP2. And keep in mind, those are capped to 30fps.
The guy was asking to use Cell with alpha-blending - I said moving it to Cell solve bandwith problem but probably creates a computational one instead. Maybe I'm misreading something...Laa-Yosh said:
Raycasting against tesselation/subdivision surfaces is actually not hard (and it's been used for physics/AI at since PS2 days(that I know of)). Unless you start animating displacement maps it should be fine.
Collision tests are gonna be more costly, but it's not like CPU-only physics had much future left to begin with.
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