Supporting mobile and desktop/console, best workflow?

I’m working on a game for mobile/PSVita and PC/PS4, this game is a fully 3D game with outdoor environments. The graphics on the PC/Desktop must be much better than mobile.

I use Unity 5 pro and Speedtrees which come with mobile and desktop versions but don’t share the textures unfortunately.

I was going to write a simple script that swapped the mobile versions of models for the desktop version, however with speedtree not using shared textures, would that bloat my mobile build size?

Would I be better creating separate scenes for mobile and desktop? I’m trying to not do this but I’m not sure if I have much choice?

Thanks

While I don’t know if there is any use in splitting up scenes for different platforms, I guess using preprocessor directives could be helpful. ( Unity - Manual: Conditional compilation )
At least that’s what I use. I haven’t tested it, so I’m not positive about Unity actually stripping away the textures mentioned there. I do hope so.
For example:

var rock_obj : GameObject;

#if UNITY_IPHONE
var texture_rock01_lowres : Texture2D;
rock.GetComponent.<Renderer()>.material.SetTexture("_rock_texture", texture_rock01_lowres);
#endif

#if UNITY_STANDALONE_OSX
var texture_rock01_highres : Texture2D;
rock.GetComponent.<Renderer()>.material.SetTexture("_rock_texture", texture_rock01_highres);
#endif

When building the app for iOS, texture_rock01_highres should not be included in the build - I hope.
Maybe someone can confirm this?

EDIT:
Also, you probably don’t want the same textures / texture resolution on mobile and PC / consoles anyway. I don’t know about the resolution sizes you are working with, but having too many high-resolution textures on mobile will probably have an impact on performance rather quickly.

Thanks for the reply.

I was thinking of instantiating desktop versions of the models with desktop res textures etc, but I’m not sure if they’ll bloat the mobile build. Perhaps I’ll just have to try it and see what the results are…