[Bf-committers] Proposed default margin increase for baked textures

[metalliandy]

Hey everyone,

I want to propose a change the default margin value that is currently 
used when baking textures.

The current margin of 2px is no where near enough and really doesn't 
help anyone due to the fact that it only is enough for the initial baked 
texture and not for any further mip levels that may be needed. As I'm 
sure some of you may be aware, you need at least 1px of margin per UV 
island to be correct for each mip map level as the texture is resized 
down, in order to stop the background colour from bleeding into the UV 
islands.
I would recommend using a value of 16px as the new default as this would 
allow for 3 mip levels in addition to the initial bake, as long as the 
background colour is correct) which should be enough in most cases as 
the texture is resized down (16px>8px>4px>2px).
Ideally of course we would set the margin so high that there is actually 
no background colour, but I don't think that many people would go for 
that as some feel that it makes the texture look messy, however 
irrelevant this may be, some people do care about how their textures 
look even if you will never see margin on the final mesh. ;)

Please take a look at the link below for an example of what an incorrect 
margin value can look like when viewed on your mesh.
http://blenderartists.org/forum/showthread.php?279870-seams-artifacts-with-tangent-normal-map-in-blender-and-unity

For clarification, this is applicable to all baked textures, not just 
normal maps


Cheers,

-Andy