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General Category => Anim8or v0.98 Discussion Forum => Topic started by: flametiger74 on March 27, 2008, 01:40:56 am

Title: Can somone explain the what AA sampling is?
Post by: flametiger74 on March 27, 2008, 01:40:56 am
The subject explains it all. :)
Title: Re: Can somone explain the what AA sampling is?
Post by: RudySchneider on March 27, 2008, 02:52:02 am
The Internet is your friend.  Type "anti-aliasing" into the search window, and you'll find all sorts of info.  Such as: http://www.pantherproducts.co.uk/Articles/Graphics/anti_aliasing.shtml
Title: Re: Can somone explain the what AA sampling is?
Post by: Steve on March 27, 2008, 07:11:10 pm
flametiger74, are you referring to the different sampling methods in the AA setup dialog?  Those are simple different strategies for sampling the image when computing a pixel's value.

Anti approximates the light that reaches a pixel by evaluating multiple places within that pixel and blending the values together.  Sample methods are different ways of placing the samples.  All of these methods except Random first divide the pixel into a regular grid of NxN.  Then:

Regular samples a fixed set of regular positions, one per cell.

Jittered picks one random location in each cell.

Multi-juttered further subdivides each cell into another NxN sub grid.  Then it picks a random location in the a sub grid location but always choosing a different sub grid cell for eack main cell.  This is probably the bes method for sampling most images.

Random is just random locations.  It isn't really that good because it creates too much noise for a given number of samples.  But some people like it because it looks a bit like film grain.