I know there's been a couple of threads about target painting so far (and a lot about simple spotting), but I feel this is different and would work with what we already have, so bear with me. I also know that CCP has Target Painting listed in their weekly thread, but I have no idea what iteration of it they find "interesting." TL;DR at bottom.
Similar to things thrown around in this Target Painting Thread (
https://forums.dust514.com/default.aspx?g=posts&m=532484#post532484) and this one (
https://forums.dust514.com/default.aspx?g=posts&m=450275#post450275), Target painters would be used for the direction of indirect fire.
Currently, the only weapons that could really do any kind of indirect fire are missile weapons, and missile weapons (vehicle and turret ones, not so much swarms) are underpowered in the opinion of quite a few. This idea might hopefully make them a bit more relevant.
Idea:
Target painters are used by a forward observer to paint an area. It could be an objective or a patch of ground, or even a dropsuit/vehicle if the painter is skilled enough to keep a bead on them. Once an area has been painted, a reticle will appear in the sky over the area for any missile turrets or tanks. When shot at, the missile from the missile turret / tank would arc through the air over LoS obstacles and onto the patch of ground that was painted. Depending on how close to the center of the reticle the shooter can get their aim, the more accurate the bombardment would be. If/When Minmatar tanks get introduced and have projectile artillery cannons, they could also fire at the "sky reticle" and deliver faster-incoming fire. Missiles could possibly track the mark, giving an advantage to them in accuracy over a faster but 'dumb' projectile bombardment.
Of course, painting an area behind a rather tall structure or under a roof would only result in a scorched buildingside/roof. This is
NOT a "missiles will fly around any and all obstacles to reach the target painted area" idea.
Sub-idea: Swarms could lock onto the painted mark, allowing for 'dumb' fire of swarms into the area, or possibly track the painter-ray, allowing a skilled painter + swarmer two man team to take out infantry.
This way, missiles are more useful and can be used for artillery support, and swarms could possibly be used for area-denial (as direct hits would still be hard to come by against anything non-vehicle).
TL;DR : Target Painters would mark an area and create a floating reticle for indirect fire to aim for to give long-range indirect artillery support.