How To Get a Render back to my initial UV Map

[micheus]

I'm going to left my thoughts about your comments. Don't see that as a definitive answer/comment. I'm not a expert.

The problem is that it is not enough good when I look to the renders in the the forum.

It is probably a problem with textures materials that I don't enough master in Photoshop. Here is my question with Kerkythea.

I don't think you could get in your simulator a similar result to those produced by a dedicated render. Those images you see usually take long times to be finished and a simulator requires a real-time result. So, depending on the simulator capabilities you may get better result in some way. The texture you paint is only part of what you see as beautiful. There are a material description which will define (using image maps) how shine, translucent, detailed and other attributes you models will looking like.
Some 3D apps/game engines use PBR or PBS render system that improve a lot the quality of a image in run-time.

By the way is there free 3d painting or texturing soft, the Wings 3D palette seems to be light, or I missed some important things?

Sculptris can do that. (samples)
There is also an online tool SculptGL that can do that, but you know all these free tool are not so powerful - you need a bit of patience to get a good result.
In both cases you can load an .obj file.

Just out of curiosity, what is the fly simulator you are using?