cover generating auras, Ht and LoS

[solkan]

There are a few different actions and abilities which generate cover of a specific height.  For example...

Howard Langston (Ht 3) has Steam Cloud:

(1) Steam Cloud: Until the start of this model’s next Activation, the area 4 around this model is considered Ht 5 soft cover terrain for the purposes of drawing LoS.

The Hodgepodge Effigy (Ht 1) and the Cooligans (Ht1) have The Mist:

(1) The Mist (Ca 4 / TN: 12): Until the start of this model's next Activation, the area within4 of this model is considered Ht 3 soft cover.

As far as I can tell, both of these actions are creating an aura of one height (the height of the originating model, since it's not specified otherwise), and then the area covered by that aura is considered terrain with the specified other Ht value.

From the rules for auras:

An aura has the same Ht as the model it comes from, unless specified otherwise.

By default, all objects within the aura’s area, including the model it is centered on, are affected by the aura until they are no longer within it or the effect ends.

which is then subject to qualification by "Auras Blast and Pulse LOS":

A model cannot be affected by an aura or pulse that emanates from a location out of LoS.

In addition, a model cannot be affected by a Blast Marker if the original target of the blast effect is not within LoS of the model.

Is that callout box creating rules that only apply to models in auras, or is it supposed to be read that the area of an aura is constrained to line of sight, period?

In other words, Howard Langstone is standing next to a Ht3 wall and uses Steam Cloud.  Howard Langston can't draw line of sight to the Ht0 terrain on the other side of the wall. 

I think how this is supposed to work out is that Howard Langston standing next to a 2ft long Ht3 blocking wall creates a not-quite semi-circular Steam Cloud effect, so that he's in Ht4 cover and the ground on his side of the wall becomes Ht4 cover within 4" of him, but the ground on the other side of the wall isn't.  But this all seems complicated enough that I'm second guessing myself.

 

[solkan]

A diagram to make things clearer:

So Howard Langston is standing next to that Ht3 wall, and uses Vent Steam.  The area marked in Bright "Don't draw a circle using a trackpad" Yellow is roughly the area of the aura that Howard can see, so that's the area that becomes Ht4 Soft Cover.

The Death Marshal checks line of sight.  The red line of sight line to the Oxfordian Mage crosses the yellow area, and model is within 1", so it gets cover.

The Death Marshal checks line of sight to the Coryphee Duet.  The blue line of sight doesn't cross any of the light cover area, so no cover for that model.

Is this how it's supposed to work?  Or is the whole circular area supposed to become Ht4 Soft Cover?

 

[Myyrä]

LoS only exists between two models. There are no rules for drawing LoS to a point in the field. Considering that and the fact that the Aura rules only talk about drawing LoS to models as well makes me think that there is actually no rule demanding that a model would need LoS to generate soft cover terrain. But why are they Auras if they don't need LoS...

[solkan]

1 hour ago, Myyrä said:

LoS only exists between two models. There are no rules for drawing LoS to a point in the field. Considering that and the fact that the Aura rules only talk about drawing LoS to models as well makes me think that there is actually no rule demanding that a model would need LoS to generate soft cover terrain. But why are they Auras if they don't need LoS...

Specifically, no, the mechanics for drawing line of sight are defined in two paragraphs.  The first paragraph defines how to draw line of sight from a model to a model. 

Quote

To determine LoS from a model to a target, the players will draw a series of imaginary straight lines from the acting model to the target model. These LoS lines are drawn from anywhere on the acting model's base to anywhere on the target's base. We assume models represent non-static characters who bob and weave a bit on the tabletop, and using the base to determine LoS serves to represent this.

The second paragraph defines how to draw line of sight from a model to an "object":

Quote

When drawing LoS to an object, the lines are drawn from a “top down” view ignoring all vertical height. The model's Ht stat does, however, come into play when determining the quality of the LoS.

Whether you want to read that as supplemental or parallel definitions, line of sight is required to be defined between models and markers.

In part because the FAQ has a question concerning it, between models and markers:
 

Quote

 

49) Q: If a model on a 30mm base is positioned perfectly on top of a 30mm Scheme Marker such that the Marker is completely covered, can other models draw LoS to the Scheme Marker?

A: No. Note that in the case multiple Scheme Markers are stacked on top of each other (with nothing else on top of/ blocking them) models may draw LoS to all Markers in the stack because Scheme Markers are not blocking.

 

and in part because there are at least two instances of the phrase "target marker" in Crossroads, when the whole big deal about 'target _____' is the default requirement for the target to be in range and line of sight to the acting model.  So line of sight isn't something which only exists between models.  And since markers don't have Ht 'unless otherwise noted', the ground not having a Ht value shouldn't be a mechanical issue--if you can draw line of sight to a marker, you should be able to draw line of sight to a point on the ground.  (Disclaimer:  I don't know whether you're supposed to draw line of sight to a point on the ground, I just mean that mechanically it's defined well enough to be carried out.)

One concrete point for "Why is this effect an aura?" would be because of the defined behavior that auras move with the model:

Quote

An aura is centered on a model and radiates out in all directions from the edge of the model’s base and moves with that model as it moves.

If these were just 'area within 4"' effects and not auras, you'd be guaranteed confusing questions about whether these effects stay in place if the model gets obeyed or forced to move somehow.

 

[Myyrä]

23 minutes ago, solkan said:

and in part because there are at least two instances of the phrase "target marker" in Crossroads, when the whole big deal about 'target _____' is the default requirement for the target to be in range and line of sight to the acting model.  So line of sight isn't something which only exists between models.  And since markers don't have Ht 'unless otherwise noted', the ground not having a Ht value shouldn't be a mechanical issue--if you can draw line of sight to a marker, you should be able to draw line of sight to a point on the ground.  (Disclaimer:  I don't know whether you're supposed to draw line of sight to a point on the ground, I just mean that mechanically it's defined well enough to be carried out.)

 

There are instances of drawing LoS to markers in all the books, and I'm aware of that. Markers are different from points in the ground because they have a base and Ht, so it's easier to apply the LoS rules to them.

[solkan]

32 minutes ago, Myyrä said:

There are instances of drawing LoS to markers in all the books, and I'm aware of that. Markers are different from points in the ground because they have a base and Ht, so it's easier to apply the LoS rules to them.

Markers usually don't have Ht:

Quote

•Markers do not count as terrain and have no Ht unless otherwise noted.

and that 'unless otherwise noted' clause sure seems to cover a large portion of the marker population.

The fact that they have a base means that more of the line of sight rules apply to them, but processing how to draw line of sight to a marker on the other side of a wall still requires a bit of null-based comparisons ("Does the thing with an undefined Ht have a Ht greater than this terrain element?  No.").

 

[lusciousmccabe]

I think the idea behind auras with a Ht value is to let them function without requiring line of sight. This lets models hide out in something like a steam cloud while in front of Langston which they wouldn't normally be able to do unless they are shorter than him.

Unfortunately that's not referred to specifically anywhere I'm aware of and the rules don't really support it that well if it is the intent.