After a lot of attempts to bake correctly I have this result.  But as and before I have a tiny little dark areas. I tried to clear seams  (if this areas laying on between two meshes) and after unwrap objects and pack UV and save it. After I have changed margin in baking options, and from one attempt to another I have different result (dark areas transform to other positions), but no one is clear AO map.. Face orientation is correct and I haven't seen the stretches on the UV (there are simple forms of tank body). Can you advice something to check or what would you do at first with areas?

https://cgcookie.com/lesson/painting-with-layers-in-blender?wtime=296

When I go to shading viewport mode, I don't have that environment skybox, I just get a black background, how do I get that?

Hey, after baking the ambient occlusion it looked like this:

Even though I put 4px and unchecked the turret from rendering, what am I doing wrong?

Hello, I have an issue with AO baking, like someone mentioned before. I tried baking the turret separately from the body and the extra mounting gun, but I get this:

As you see, the baking barely even works for the turret. The barrel has a bit of gray in it and the turret only has baked the two small barrels and the front part. The UV unwrapping was done properly and the margin is set to 4px. The render settings (CPU or GPU) did not make a difference. I recalculated normals inside and outside as well. I also checked for any topology problems like double vertices or overlapping faces. The UV image is at 2048x2048 for PC usage.

Should I multiply the AO texture? Should I use a separate AO texture for turret?

I could send the file to anyone who is interested on fixing it. Thanks!

Not a question but a note. In texture mode only the active object is available. It took me a long-time to work this one out as it is different to UV mapping where you can work on all objects.

Took a few days for this particular lesson as I am new to everything. I had to learn from the ground up before completion. I did not initially find it intuitive but going away to learn about data blocks helped.

For now I have kept the Principled Shader in place and the maps are 2k

I also found that instead of multiply using Burn with a factor of 0.18 gave good results.

Thanks for the tutorial

I've had Blender freeze 6 times in a row whenever I try to paint on the main body in any way. Painting on the turret works fine, but painting anywhere on the main body makes the program freeze.
I tried painting with a tiny brush and it worked slightly, but seemed to really slow down the program, and as soon as I touched a corner/seam it froze again.

Any idea why this happens?

Edit: I tried painting on the source file tank body and it worked just fine. Is it something to do with my unwrapping?

Hey there! I got this far, and baking produces a really weird effect. All the textures appear banded, and I also have a black line running straight through the tank body. I double-checked, there's no seams there. The turret is also completely black, even though it's been unwrapped with the rest of the model. 

Since I was interested in desktop renders, I decided to begin the texture at 2048x2048 like you mentioned in the previous video. I attempted to adjust Cycles render size before the bake as well, but no luck. 

Also adjusted the AO size in the world settings. Tried at both 5cm and 1m distance.

Thinking it may be a bug, I upgraded to the latest Blender 2.8 release, but same effect. 

All out of ideas because texture-space is totally new to me. Any help is much appreciated! :)