Print

[xmaniac2003]

In EVERY game the shadows look n64 style the xbox shadows looked way better so why this change in the 360... It just looks well its sickening... sorry if in wrong forum.

[Deftech]

Ummm

can you be a little more specific?

what games have you played?

Shadows/Lighting in Condemned is phenomenal. Q4 looks great too.

What are you talking about exactly? shadows from people in sports games? Pd Zero? kameo? Character shadows?

Or shadows within the environment?

[prankfurter]

for me the shawdowing is amazing, condemed, kameo, nfs:mw the shawdows look really good...

[xmaniac2003]

WOW really well they look like crap for me is my AA off or something? yeah your player shadow or any shadow looks like big squares no smooth edges at all. whats up am i the only one with this prob?

I will try to get a pic up soon

[hamwbone]

what game??

[Deftech]

xmaniac2003, you are still typing gibberish.

what effing game are you talking about?!

Don't make me pull out the " *sigh* "

 

Hahahahahahahaha

hamwbones avatar just lifted my spirits  

[themadman123]

To me its not so much the shadows that bother me, but it is the fact that everything glows so much it makes it look not as good. I don't understand when I play FIFA all the players look like they are parts of the sun and glowing so bright that it hurts your eyes.

[xmaniac2003]

BAH omg i am a fing idiot sorry its only online that the shadows look horrid. and it ALL games out right now i guess its to improve performance or something and it only happens in single player sometimes and i repete ALL games out now...

[Deftech]

oh my shit

my head

someone remove it

[m_hael]

I must admit to not seeing any issues with shadows whatsoever however, I'm not a graphics whore so I probably just accept whats there.

I'll write something up to explain how differing techniques work and hopefully that might help you understand why the shadows might exhibit more aliasing that the rest of the frame - gimme a day or so tho.

[m_hael]

there are 2 main methods for shadows: shadow buffers & shadow volumes.

shadow buffers render from the point of view of the light into a temporary buffer of finite size (say 1024x1024). This buffer is then projected onto the geometry it affects as a lighting pass that is used to multiply the initial light value; one represents unocclued light, zero represents occluded light.... thus when a light is occlued it doesn't affect the poly at all and thus appears in shadow.

shadow buffers suffer inherently from aliasing in that they are calculated in a light space and then used in screen space,  the size of the buffer and the geometric area it is used to cover defines the amount of visible aliasing you see in the frame buffer, the smaller the area you cover and the larger the buffer the less aliasing you get.

some engines attempt to get around aliasing by using several buffers of varying sizes covering sections of the geometry from the camera into the Z distance in camera space, thus the close up shadows have a sharper look using a larger buffer than the distant shadows... this does however result in a distinct line in Z space where the shadow loses the sharpness.

another problem with shadow buffers in general is a sharp edge to the final shadow (often aliased) that represents the hard edge of the geometry being rendered into the shadow buffer. There are techniques to get around this by rendering the geometry into the buffer at varying offsets creating an outer and inner pernumbra which then results in a softer shadow. This technique is not often used however due to the fill rate required and is more often seen in cutscenes than in actual gameplay.

Shadow volumes use edge detection to extrude the edge of geometry in the direction of the light and essentially generate new geometry representing the volume IN shadow. This new geometry is then used to render in a specific rendering method using the Zbuffer rejection to map out the rendered pixels that are IN the shadow. This buffer is then overlayed onto the main screen as a post process essentially darkening the pixels already rendered through the lighitng system.

shadow volumes will NOT alias as they are rendered IN screen space however they will exhibit a VERY hard edge with no accurate method to smooth that edge out without obscuring pixels that are NOT in shadow however this is used in many engines and no one notices so its all good in the end.

shadow volumes suffer extremely badly from fillrate issues as the rendering technique used to generate the full screen shadow map requires that the geomtry extruded must be extruded to infinity or some arbitrariy guaranteed distant point. Either way it requires a LOT of pixels to be rendered. Because of this shadow volumes are not widely used as a full scene solution but more of an overlay onto pre-computed lighting or as a more accurate second pass to shadow buffers giving characters a screen space none aliased shadow.

personally I would always use shadow volumes with several buffers in Z space and a VERY high resolution mode for cutscenes that may or may not use the soft shadowing technique.

both these techniques can be extended to multiple lights but will obviously suffer badly from fillrate the more lights you apply them to. Most engines do one light only and possibly blend in and out as different lights come into the focus of the camera (POP:WW).


So - in short a game that exhibits aliasing in its shadows on x360 probably does so because the screen is such a higher resolution than the original xbox and shadow rendering wasn't upgraded for whatever reason to compensate for it. You can increase the size of the buffer but there is no size that will remove ALL aliasing.

other techniques exist so if you want to read up on them just google for "real time shadows" and you should find plenty to read.

[m_hael]

that is shadow buffering using a low resolution buffer... increasing the size of the buffer or switching to view space shadow buffer (nasty complex math heavy technique) is the only fix

[Darcom]

Condemned has amazing shadows they even scare me sometimes  

[twistedsymphony]

The only time I've noticed this is in PGR3 in the cockpit view...

I haven't seen it in any other game in any other mode or view.

[Vinestrike77]

Great study seesion on shadows, too bad I only understood half of it. The games that I own (NFS-Most Wanted, CoD2, PDz, Condemned, NHL2k, and Madden) have great shadows and nothing to complain about.

The most authentic shadows are in comdemned where the light coming in from the windows cast a great shadow onto dark rooms and freaks the s*%^ out of me since I think that I have a freak two feet away from me and start to beat the s*%^ out of the wall with my axe.