From the Front - Smoke

[ComradeP]

Interesting post.

You can completely block LOS to the artillery units by placing two smoke rounds south of them (as in, 1 in each hex 1 hex below their positions). The central hex in between them is also forested, so it blocks LOS.

The artillery units in your example are hidden until they fire due to the terrain they are in (they would also be hidden if they switch to T mode, provided they're not spotted whilst doing so). Screening them with smoke is primarily useful for allowing them to switch to T mode and either move out of their hex in the same turn or the next.

It's important to keep in mind that LOS is a cone of sorts, so units can see around "corners" in the sense that their LOS is not limited to straight or diagonal lines from their hexrow. That makes placing smoke further away from the units you want to screen/blind less efficient.

In some cases, units in clear terrain that have not moved are also hidden (up to a certain distance it seems). I'm not entirely sure how that rule works yet. In the Ozerovskii scenario, the same one as in the first example, the Soviet light tanks that function as triggers for their tank brigades spot my units before I can spot them, even though the light tank units are also in clear terrain. A special visibility rule might apply to Fixed units in clear terrain, I might've missed it.