Luca Troian, While I think Paul comes off a little aggressive, he is correct. DPI is meaningless when creating a computer generated image. What does matter is the output resolution and your field of view. The math is fairly simple as long as you know what you are setting up in advance.
I'm going to use small numbers for simplicity's sake, but the math is still the same for larger numbers. If you want to render a image of a box in 300 dpi and you want a image size to be 2x1 you must make the output resolution 600 pixels x 300 pixels and using your position in frame and the field of view slider you can create a image that fits your parameters. There might be some image size scaling in Photoshop that will be required but that's one step at most. A DPI selector will only be necessary from Enscapes point of view if they add a new output option that lets you base the image size on a in/cm width and height.
The only reason the blue box exists in Photoshop is because of the information in red box. Enscape doe not have image parameters based in real world dimensions(red box) so the blue box is not necessary.
Thank you Tearch for your kind answer, so appreciated, I'm not arguing about the fact that dpi is a unit of measures about density of point in a printed area, so, on a screen, has limited sense, cause it's a screen not a printed piece of paper, but many of us need to print, and the difference is preatty clear, and when you go bigger is very clear... (in one case needed a 3x4 meters (9,8x13,12foot) and need to answer to client about limits of this plug-in) or in other case needed a thypographic print.
I said limited sense, I imagine we all heard about same dimension monitor with different resolution, like 2k and 4k monitor for same dimension 27" screen.
Are you saying that there's no difference about density of point on it? So why did exist this monitor? it's a difference preatty clear even with smartphone.
All screens quality has both expression in resolution and density so dpi, maybe dpi isn't that precise as meter of comparison but isn't meaning less even on screen.
For this reason I renew the request for a 300dpi option, that is an oportunity more, for all user of our beloved plugin.