How I can add graphics in OTTD?

[Borisov]

I have downloaded new graphics with extensions .blend . How I can add them into the game?

[MeusH]

Unfortunatelly you can't. These are 3D models.
In the future, the 3D models will be rendered to 2D images which will be put to OTTD world just like current 2D images (houses, industries, grass, vehicles) - Just with better quality