how manage mirrored normal maps

low_seb

hello everywhere

I am having problems with some mirrored normal maps , not for the baking high poly-low poly but with some d

Eric Chadwick

What software and rendering method are you using for the first image? The shader must support mirroring. Also the mirrored UVs usually need to be offset in UV space (like this).

Noors

A normal map takes place in repair defined by the face normals and your UV's (the famous tangent space)

So if you're uv's arent oriented the same way (here you have 90° or 180 rotations), the normal map patterns shouldn't have the same look.
It also means that you can't simply rotate a normal map with the transform tool.

In your case, its rotated by 90°, which is fairly simple. You need to invert the red or green channel at some places. Go to your red or green channel, select the wrong part , and CTRL+I for negative, till it works.

You also have this script to rotate a 2d pattern at a custom angle http://blarg.robertkist.com/?p=11

Eric Chadwick

Oops, right. :poly136: The OP rotated the UVs, but the normal map colors are not representing the rotation.

low_seb

its render in unity , and before baking I delete the mirrored part
the issue its just on the potoshop added part , I suppose if I make this detail in my high poly
the baking would be fine

low_seb

your solution work nice for the added detail but not for the originally baked normal
I suppose if I invert in my height maps those parts before crazy bump ,it would be ok
or maybe rebake from the high poly by flipping these parts?

thanks for help

Noors

Ah, yeah ofc, the baking from the 3d object is correct. You only need to edit the 2d details.
I think you should generate that detail map in crazybump, edit it in photoshop, then combine in crazybump.

Yes, the issue is with the 2d images. If you had modelized those parts in 3d, you wouldn't have any problem, or atleast, not this one ^^
That's the limit of 2d editing. It's great for tiled texture, like a wall, or whatever, but for a 3d model, with uv's in diffrent directions, it becomes tedious to get a coherent result.

low_seb

probleme solved , the next time I take care of the uv orientation for a better result
thanks again for the help

Noors

You're welcome.
You still have a problem on the black dots tho

low_seb

just showing the result