So as many folks are finding out, there are some issues with how line of sight abilities target enemies near many pieces of terrain. This is nothing terribly new, but I think now is a good time to consider updating how these calculations occur given the renewed community interest in them.
Core Problem:
Line of Sight abilities feel inconsistent when used near certain pieces of terrain. The main offenders seem to be slopes, railings, small decorative elements with collision, and the very organic shapes in orokin derelict and infested tile sets.
Suggestion:
Instead of deep diving every piece of terrain and creating a huge burden on the environment design teams (or worse limiting their freedom to create fun environments) lets aim for a more general fix using pieces of design that already exist elsewhere in the game that should address most of the problem situations.
Lets model the line of sight check for abilities on the check used to determine if a hitscan weapon connects with some nominal quantity of standard punch through and infinite body punch through. Have the origin point be wherever the ability starts from (presumably the player, but could be where the reticle is pointed) and the trajectories be the straight line from there to each enemy in range. If there is too much stuff in the way the check fails and the enemy is safe, otherwise they get hit by the ability.
By dialing in the desired amount of punch through, abilities would be able to hit through small obstacles but not through multiple walls.
From a computation standpoint we know that the game should be able to handle lots of these calculations very quickly, otherwise weapons like the Soma, when modded for punch through, would send the frame rate into the ground.
Variant Suggestion:
If folks want to get really fancy with it, you could even scale the damage/effect of the abilities based on the percentage of the punch through that was needed to target an enemy instead of simply being a binary "hit" or "not hit" result. (i.e. if an enemy was behind 1.5 meters of stuff and the ability punch through was 3 meters, then that enemy would take 50% of the damage that ability did). While I think this could be a cool addition, it is also more complicated and not core to the suggestion.
Conclusion:
Overall I think this style of change would make the line of sight targeting feel a lot more intuitive for players and means that small bits of collision or slope weirdness won't interfere with targeting. By using punch through as a way to rework the calculation it also somewhat future proofs the issue, since all terrain already needs to be built to handle interactions with punch through since it is a stat that can be on any ranged weapon.