Blender Joining (CTRL-J) Causes Problems

[Grim Bracken]

Hello all,

 

I'm having an issue with joining objects in Blender and I'm wondering if others have experienced this. When I join objects some of the objects seem to lose their UV Maps. Everything will look perfectly mapped before I use the join function. Also, sometimes the normals will be reversed.

 

Does anyone have any advice for avoiding this issue?

 

Thanks,

Grim Bracken

[Grim Bracken]

[Jake Koronikov]

At least in about version 2.6 (or later) Blender this can be avoided if you keep the uv-map names same in both objects.

So, for example, if both objects have only one uv-map and you name both of them as "UVMap" -> should solve the problem.

 

[Grim Bracken]

That helped a lot Jake. Thanks. the two affected objects had a name of "Orco" instead of "UVMap". After changing them to "UVMap" they joined perfectly. Still have the issue of the normals reversing though.

Edit: Recalculating the normals seems to be working pretty well. Not sure how the normals get messed up by joining in the first place.

[DerpWolf]

Normal flipping usually occurs if attached object was mirrored (negative transform) Before joining, apply the mirrored copy's scale and rotation, and if normals become reversed, flip them the correct way.