If you are just looking for a render that is flat, switch to unlit mode (hotkey: Alt + 3) prior to rendering. If you want this to occur during gameplay, you could also consider using a post-process material to impact the entire scene.
If you are just looking for a render that is flat, switch to unlit mode (hotkey: Alt + 3) prior to rendering. If you want this to occur during gameplay, you could also consider using a post-process material to impact the entire scene.