I finally found the origin of the problem and how to fix it.
You can test it from the version 3.4 beta 31. As some users may have lost a lot of time to adapt their texture to circumvent this bug, I took care of keeping existing rendering unchanged, and the fixed behavior will be applied only to models you will change texture from the coming version.
The new behavior is to apply the texture from the left and bottom borders on the front side of an object (the side with a thick black line when the object is selected), whatever its coordinates used in its 3D model file. The new behavior ensures also that the texture applied on a wall is correctly oriented whatever side (the left side of walls used to display reversed textures).
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Emmanuel Puybaret, Sweet Home 3D creator
