Maybe instead of a flashlight, we could instead have "night-vision goggles" or a
"Night-Vision Mode"
available when wearing your space helmet.
It could kind of function in 3 layers:
(
1 2 3)
- It could function kind of like lighten-mode by lighting up all the blocks in your field of vision (and just to the player using it, so it would be client-side (which is easier, right?)).
- But then, on top of that (the lighten-mode), it could have some kind of shader (like the shield-effect shader), that would tint all of the blocks a greenish (or perhaps a color of the user's preference), and make it look more night-vision-y.
- Then there could maybe be a final layer (that would perhaps be toggle-able), that would identify the type of block the player was looking at in sort of a Heads-Up-Display(HUD)-type fashion (perhaps up to a certain distance), like is done in build mode, similar to what NeonSturm suggested (but much cooler looking than build mode, and more HUD-y). Maybe the HUD-identifier could also identify the types &/or names of mobs & astronauts that the player looked at, as well as names of ships.
I'm not sure it would really be as "cool" as a flashlight, but it might be much more do-able alternative.
And it kind of fits the genre/setting of the game a bit better too if you think about it.
...Just an idea.