Blender 2.6 and 2.4 produce different normal maps

Hi,

I am using the object-to-object baking technique to bake the normals of a high poly object onto a low-poly object. I’ve noticed that Blender 2.49 and Blender 2.60 produce a different baking output when using the same .blend file.

Here’s a comparison:

Blender 2.49:
http://scrawl.bplaced.net/perm/24.jpg

Blender 2.6:
http://scrawl.bplaced.net/perm/26.jpg

I “solved” this by inverting the red and green channels in the 2.6 map, now they look the same.

I didn’t find any documentation that this was changed in 2.6, so maybe is it a bug? Or are there other reasons why it inverts the R and G channels?

strange!

how and where can you change this?

thanks

I remember reading that during 2.5x development the normal map treatment was changed in comparison to how it was done in 2.49b.
That may explain the different result there.

Do you have a link?

Ok I found a link to the commit that changed it:

http://lists.blender.org/pipermail/bf-blender-cvs/2011-February/034308.html

Its sad there is no official documentation on it anywhere, it took me half an hour to find out what was wrong with my normal map.

this last paper seems to refer more for the export of normals then what is done inside blender!

salutations

how about this? --> http://lmgtfy.com/?q=blender+tangent+space

can someone explain where you can change the red and green channel in 2.5 ?

thanks

In the UV Image editor, use Image -> Invert

Note that you don’t have to do this if you only use the normal map inside blender. It is necessary when using them in another game engine (ogre, etc) - for ogre, with a normal map from blender 2.4, you have to invert the red channel, with a normal map from blender 2.6 invert the green channel.

Hi mikkelsen, thanks for your reply. I didn’t use “tangent space” in my searches (since this also occurs in object space etc). That page is quite useful - but it doesn’t explain what the r,g,b output in the baked normal map means, which is what I was searching for. Only finding outdated information of 2.4