How the Wii renders edges

[MayImilae]

(01-30-2017, 07:23 PM)joques Wrote: Didn't really get the answers I had hoped for I was certain someone in the know would jump in and say "Well, the reason the CG (and by extension the Wii) renders polygons in this particular way, is XWZ. This is bad in way A, but good in way B, and what it allows us to do in Dolphin, is C."  Oh well.

This isn't like with the PS1/N64 comparison where they took fundamentally different approaches to rendering and it's fascinating to read about. By the time of the 6th gen, rendering polygons in a 3D space was more or less figured out, and everything stuck to the same basic techniques. So it's not really that interesting. Of course if you get really specific there are a LOT of differences, especially in what they do with the image after rendering, but those differences are much more subtle and harder to explain (unless you are really into this stuff!).

[joques]

(01-28-2017, 07:43 PM)DrHouse64 Wrote: Also, the fact that most PS2 uses EAA doesn't mean that people want that. Some people prefer to see a jaggy but clean image instead of a smooth but blurry image. It's up to everyone.

I don't agree that this is the case with PS2. Sure, some games take it too far and are blurry. Silent Hill 2 and Dragon Quest VIII specifically seem to me to take it too far. But there are many that manage to thread the needle and find that magical sweet spot where the line is both smooth and sharp at the same time. Shadow Hearts is a good example. Disregarding the prerendered backgrounds, that seem to be rendered at 240p, the character models are sharp and detailed, yet not especially jaggy, at least when close to the camera. Mercenaries: Playground of Destruction is another one. Sure, there will be some jagged edges here and there, but overall the sensation is one of "sharp, yet smooth". Maximo is yet another example. Dark Chronicle is another. In fact from my own limited experience it seems to be the norm, and not the exception.

Now like I said, I run them all through a Framemeister, and some of this might be down to how the PS2's interlaced signal interfaces with it vs. how the Wii's progressive signal does it. Still, the upshot is that I can't play Wii games on original hardware anymore, so thank the fates for Dolphin!

[DrHouse64]

(01-30-2017, 07:23 PM)joques Wrote: Didn't really get the answers I had hoped for I was certain someone in the know would jump in and say "Well, the reason the CG (and by extension the Wii) renders polygons in this particular way, is XWZ. This is bad in way A, but good in way B, and what it allows us to do in Dolphin, is C."  Oh well.

The answer is as simple as most PS2 games uses AA, most GC/Wii don't. It's really not more complicated than that.

[joques]

(01-30-2017, 09:06 PM)DrHouse64 Wrote: The answer is as simple as most PS2 games uses AA, most GC/Wii don't. It's really not more complicated than that.

Sure, but the interesting question then becomes: Why were these choices taken, and what did they gain from making them?

[AnyOldName3]

If you don't spend time doing antialiasing, then the GPU can do something else, like use fancier shaders or more detailed models and textures.

[MayImilae]

Well it's pretty easy to answer on a basic level. Hardware anti-aliasing (1xMSAA or 3xMSAA on the GameCube) was expensive on the GameCube but apparently the PS2's anti-aliasing method (I have no idea what it is) was really cheap.

Explaining why it is expensive is a little difficult... I asked degasus and he filled me in with all the details. So, using anti-aliasing on the GameCube does a number of things.


* It reduces the color bit depth from RGB8 (8-bits per channel of color) to RGB565 (red 5-bits, green 6-bits, blue 5-bits)
* It reduces the Z buffer depth from 24-bit to 16-bit
* It reduces the framebuffer by half. Practically speaking, this meant that the game couldn't render the entire frame in time! Which would require either interlacing or 30fps to render the full resolution of the gamecube. And yet the GameCube anti-aliasing demo and Rogue Leader ran at 60fps progressive. At the moment degasus doesn't even know how that is even possible!


Soooo yeeaaa, I can just imagine a GameCube developer looking at this and going NOPE! I'm sure that with how plentiful the anti-aliasing implementation on the PS2 is it must be pretty much free.

[joques]

Awesome, thank you so much! That is exactly what I was looking for!

Edit: No surprise that Factor 5 performs magic that nobody can explain!