Sign in to follow this  
jameszhao00

MSAA Confusions

Recommended Posts

I was reading [url="http://diaryofagraphicsprogrammer.blogspot.com/2009/06/msaa-on-ps3-with-deferred-lighting.html"]http://diaryofagraph...d-lighting.html[/url].

One comment in particular was confusing.

[color="#333333"][quote]It becomes obvious if you try to visualize a 4xMSAA'ed pixel in the lighting stage. Let's say three samples in this pixel use light 0 that is green and one sample uses light 1 with the color red. Averaging the shading won't end up in correct here.[/quote][/color]


If (let's say) 4 samples of normal + z were lit and averaged, why wouldn't that produce the correct result? Is it because we can't reconstruct view/world position per sample because we don't know the sample locations? And therefore can't test light volume in/outness per sample?

Share this post


Link to post
Share on other sites
Actually, it is possible to determine sub-pixel sample locations. You could reconstruct the view or world positions even using pixel centres as well as long as you have per-sample depth values (would be little off).

But averaging the sample values into final pixel [b]is[/b] what's happening during resolving, AFAIK. Therefore I too don't understand what's the catch here. I probably didn't read the interesting discussion thoroughly enough :-)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this