Excelent! It’s working. Now I see that retina sizes interpolate between 1x sizes (As I said I created sizes for 2x and 3x retina as documentation indicates), because I add them in “sizes” array.
Instead of that, I should pass only names and add to settings array:
'retina' => array( '2x', '3x' )
Is it correct?
Sorry for being a fool.
Thanks!