From: Vermont, USA
I just read the rule.
Now I am concerned that we should set a standard for the number of model trees per unit area for each woods type. Because of the tree hit count needed to degrade sight. The distance in the woods really does not count for anything unless a ray hits a tree. There is some factor added for the terrain the unit is located on but if it is in the open and the LOS goes through a great distance of heavy woods terrain without hitting a tree it acts like it is clear.
Well, part of the rule has always been that LOS is "WYSIWYG" for the most part. With that said, we always worked with the artists to make sure the number of trees in an area matched the terrain type well so that woods would not be sparser than light woods, for example. In general though, as long as the map maker sets the trees in a way that looks like what that terrain type would look like in real life, it will work well.
It's really hard to find a "keyhole" shot like that through a dense forest (pretty much impossible) but if you do fine one such angle, the cool thing is that you can generally see in the game just how that ray passed through. Also, the minimum modifier for the terrain type the target is on is not insignificant, but for vertically obstructions it's mainly mean to represent units at the edge of the terrain area that would not benefit from any "hits" on the terrain by the ray.
Based on my testing and the feedback we've had, it works well in the vast majority of cases (with the existing maps) and I haven't seen anything in the new maps so far that would make me concerned.