Yes, it has been thought of many times. Unfortunately, it's not possible in OFP.
Most of the other games that I have seen that use some sort of thermal devices have made it possible with dual textures for every vehicle, soldier, and object in the game. This simulates the heat signatures given, by replacing their normal colored textures with new "thermal" textures. This is a feature built into the original games, but to add it to an existing game would require you to make all new textures for every single object in that game.
With OFP there is no way (that I know of) to make a filter that works similar to the NVG's, but will make it thermal. You would also have to retexture all the objects and somehow write it so that those textures are replaced when the player uses the thermal imager. It might be possible in OFP1, but I doubt you will ever see it. Just way too much work involved to make it work, and it also would not be compatible with new addons, islands, etc. unless those were retextured for thermal view as well.
If any of this information is incorrect, I'd appreciate someone explaining it better. But this is what I understand based on the time I have been using OFP, and the numerous discussions I have already seen regarding this matter.
Topic: FLIR (Read 1119 times)