Please explain "Pixel filters" to me.

[TheBadger]

I have heard people talk about them. But as is typical, those conversations were between users who already know what they are, and so the posts are not of much use to someone who does not know what they are for in the first. No complaint, just my reason for asking rather than trying to guess meanings of posts from searching the term.

So what are they, how do they work, and when should I mess with 'em?

The wiki is not updated on this topic. But I do check the wiki all the time now... There is tons of info there that was not when I started on TG, so thats really nice!

Thank you.

[Oshyan]

Pixel filters control how multiple samples (taken for antialaising) are interpolated into a single pixel value. The filter specifies the algorithm that will be used to blend sample values. You can see info on some different algorithms (including some that TG uses) here in the Renderman docs:
http://renderman.pixar.com/view/overview-of-the-render-settings

So basically the different algorithms blend samples in different ways and thus can produce sharper or softer results. Sharpness is the main difference between them that is obviously noticeable, generally speaking. And yes, there is such a thing as "too sharp" and "too soft", after all "too sharp" is what we're using antialiasing to avoid in the first place.

- Oshyan

[TheBadger]

Thank you.

[Matt]

That Pixar page is somewhat misguided and confuses some things. This is more accurate:

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Oversampling_(Antialiasing)

Just be aware that the anti-aliasing oversampling setting (5 / 8 / 11 / 16) works differently in Terragen, and the sample patterns are different from Blender. For example, to get 16 samples in Terragen you set the anti-aliasing number to 4 because 4 x 4 = 16.

Matt

[archonforest]

Link goes to an empty page...

[TheBadger]

^^ Yes for me as well.

[Matt]

I've corrected the link. Try it now.

Matt

[bobbystahr]

That Pixar page is somewhat misguided and confuses some things. This is more accurate:

http://wiki.blender.org/index.php/Doc:2.6/Manual/Render/Oversampling_(Antialiasing)

Just be aware that the anti-aliasing oversampling setting (5 / 8 / 11 / 16) works differently in Terragen, and the sample patterns are different from Blender. For example, to get 16 samples in Terragen you set the anti-aliasing number to 4 because 4 x 4 = 16.

Matt

Thanks Matt...bookmarked.

[archonforest]

I've corrected the link. Try it now.

Matt

Thx for the link. Very usefull stuff for me

[TheBadger]

Thanks!