I’ve managed to do “something” with it. I looked over all modifiers in Blender and one called “EdgeSplit” helped me (although when I used it I didn’t know what does it do I think it did something like Ardee said.
Thanks for saving my time spending on manual manifoldness checking. [BTW - the shortcut seems to be very Unix-like ]
I’ve followed your advice, checked manifoldness - deleted everything unnessesary, removed doubles, and nothing changed.
As I mentioned in the beginning of my post - I think that EdgeSplit did the same as your method? (or not?)
BTW. I’ve tried to check the “Auto-smooth” option on normal UVSphere and adjusting the “degree”, but I didn’t noticed any changes neither in EditMode nor ObjectMode. Then I realized that changes are only visible when rendering. Is there any possibility of viewing changes of auto-smooth on the fly - in edit or object mode?
Thanks for your advice - I will now on use your method.
It seems to be ok with my mesh in wireframe mode… But I do remember that I had a model in which the mesh was missing some of the edges when viewed in Wireframe mode. But in the matter of fact - it didn’t change anything when rendering. I thought that it’s non-significant bug…
Thank you all for your replies.