Snap Shot LOS and VASL LOS Tool

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Ryan Kent
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23898Figure 1

23899Figure 2

I am examining the VASL LOS function to see if it conforms to my understanding of the Snap Shot rules.

8.15 SNAP SHOT: Any unit wishing to make a Small-Arms/MG Defensive
First Fire attack may claim a Snap Shot if it can trace a LOS to an entire hexside
(even if that hexside is part of a Blind hex) that was crossed by the moving
unit in entering a on-board hex (even if the center dot of that hex is out of
the firer’s LOS) [EXC: A Snap Shot cannot be taken at a unit while entering
the firer’s hex].

Figure 1 conforms to my understanding. There is LOS to the entire F7/F6 hexside, thus permitting a Snap Shot as the target attempts to skulk from F7 to F6.

Figure 2 does not conform to my understanding and appears to me inconsistent with Figure 1. Orchards should not hinder or block LOS to any portion of their own hex, thus a unit in C7 should be able to take a Snap Shot at a target as it attempts to skulk from D6 to D7. Is the LOS tool coded incorrectly for the effects of the orchard or is there something I am missing?
 

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(Initially posted in wrong section.)
23898

Figure 1

23899

Figure 2

I am examining the VASL LOS function to see if it conforms to my understanding of the Snap Shot rules.

8.15 SNAP SHOT: Any unit wishing to make a Small-Arms/MG Defensive
First Fire attack may claim a Snap Shot if it can trace a LOS to an entire hexside
(even if that hexside is part of a Blind hex) that was crossed by the moving
unit in entering a on-board hex (even if the center dot of that hex is out of
the firer’s LOS) [EXC: A Snap Shot cannot be taken at a unit while entering
the firer’s hex].

Figure 1 conforms to my understanding. There is LOS to the entire F7/F6 hexside, thus permitting a Snap Shot as the target attempts to skulk from F7 to F6.

Figure 2 does not conform to my understanding and appears to me inconsistent with Figure 1. Orchards should not hinder or block LOS to any portion of their own hex, thus a unit in C7 should be able to take a Snap Shot at a target as it attempts to skulk from D6 to D7. Is the LOS tool coded incorrectly for the effects of the orchard or is there something I am missing?
 

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What board is that? The message and the line don't seem to indicate the Orchard is the reason.
 

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It may just be what pixel the LOS is drawn to.
It is showing the LOS was drawn to the correct Vertex; i.e. the ones "in" D6 andf F7. For example, it correctly shows as blocked in Figure 1 at the same vertex but "in" F6.
 

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You can replicate this when there is Grain on a Hill, too. Looks like a VASL issue (unless I too have the rules wrong).
 
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Hi Fanatic,

Just a note of caution: one should be very careful about selecting target vertices. If you nudge your mouse about at the vertex, you'll see that VASL reports different ranges and vertices. This may affect your results, as shown in the two screenshots below. Cheers.

Board 36

23900

23901
 

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Hi Fanatic,

Just a note of caution: one should be very careful about selecting target vertices. If you nudge your mouse about at the vertex, you'll see that VASL reports different ranges and vertices. This may affect your results, as shown in the two screenshots below. Cheers.

Board 36

View attachment 23900

View attachment 23901
I am aware. I carefully made sure the subject vertexes were those “in” the target hexes.
 
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Doug Leslie

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(Initially posted in wrong section.)
23898

Figure 1

23899

Figure 2

I am examining the VASL LOS function to see if it conforms to my understanding of the Snap Shot rules.

8.15 SNAP SHOT: Any unit wishing to make a Small-Arms/MG Defensive
First Fire attack may claim a Snap Shot if it can trace a LOS to an entire hexside
(even if that hexside is part of a Blind hex) that was crossed by the moving
unit in entering a on-board hex (even if the center dot of that hex is out of
the firer’s LOS) [EXC: A Snap Shot cannot be taken at a unit while entering
the firer’s hex].

Figure 1 conforms to my understanding. There is LOS to the entire F7/F6 hexside, thus permitting a Snap Shot as the target attempts to skulk from F7 to F6.

Figure 2 does not conform to my understanding and appears to me inconsistent with Figure 1. Orchards should not hinder or block LOS to any portion of their own hex, thus a unit in C7 should be able to take a Snap Shot at a target as it attempts to skulk from D6 to D7. Is the LOS tool coded incorrectly for the effects of the orchard or is there something I am missing?
Am I right in thinking, that in the second situation, the movement being made is into E6 as opposed to F6?

E6 is a level one hill hex. It is the target hex for range calculation purposes:

C.5C The hex containing the target by definition must include the building/woods obstacle being bypassed, or the hex the target would remain in if affected by that fire (e.g., Snapshot [A8.15], Rowhouse "Bypass" [B23.71], Underbelly Hit [D4.3]) or the lower side of a cliff hexside being Climbed (B11.42).

For the purposes of the snapshot, the hexside and its vertices are considered to be at the same level as the target hex (level 2). LOS is accordingly blocked by the orchard whose topmost height is at the same level. If the orchard were out of season, the snapshot would be possible but subject to a +1 hindrance. This is confirmed if you make the appropriate change to "out of season orchards" on VASL.
 

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Am I right in thinking, that in the second situation, the movement being made is into E6 as opposed to F6?

E6 is a level one hill hex. It is the target hex for range calculation purposes:

C.5C The hex containing the target by definition must include the building/woods obstacle being bypassed, or the hex the target would remain in if affected by that fire (e.g., Snapshot [A8.15], Rowhouse "Bypass" [B23.71], Underbelly Hit [D4.3]) or the lower side of a cliff hexside being Climbed (B11.42).

For the purposes of the snapshot, the hexside and its vertices are considered to be at the same level as the target hex (level 2). LOS is accordingly blocked by the orchard whose topmost height is at the same level. If the orchard were out of season, the snapshot would be possible but subject to a +1 hindrance. This is confirmed if you make the appropriate change to "out of season orchards" on VASL.
What I can’t figure out is why the situations are treated differently by VASL. In both cases the target is moving into a blind hex that shares a hexside with a hex in LOS. Snap Shot is allowed even if the hexside targeted is part of a blind hex. Maybe I don’t understand the meaning of that last part, but I can’t figure out why the situations are treated differently.
 

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What I can’t figure out is why the situations are treated differently by VASL. In both cases the target is moving into a blind hex that shares a hexside with a hex in LOS. Snap Shot is allowed even if the hexside targeted is part of a blind hex. Maybe I don’t understand the meaning of that last part, but I can’t figure out why the situations are treated differently.
In the first situation, there is no LOS obstacle between the F6/F7 hex side and F8. F8 has LOS to F7 which includes that hex side. A snapshot is therefore possible. In the second situation, the hex side is at level 2, so LOS is blocked by the orchard.

I have checked other kinds of terrain and I think that there might be an issue with VASL when the LOS crosses brush/grain. These terrain types block LOS according to VASL, which I don't believe is correct.
 
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In the first situation, there is no LOS obstacle between the F6/F7 hex side and F8. F8 has LOS to F7 which includes that hex side. A snapshot is therefore possible. In the second situation, the hex side is at level 2, so LOS is blocked by the orchard.

I have checked other kinds of terrain and I think that there might be an issue with VASL when the LOS crosses brush/grain. These terrain types block LOS according to VASL, which I don't believe is correct.
But A6.2 provides:

6.2 OBSTACLES: Each terrain type [EXC: Depressions 6.3] is defined as
to whether or not it presents an obstacle or Hindrance to LOS and, if an obstacle,
the height of that obstacle. LOS extends into or out of obstacles, but not
through them into hexes beyond the obstacle except in certain cases wherein
the target/firer are at an elevation ≥ the height of the obstacle or are adjacent to
a hexside obstacle.

23914Figure 2

In figure 2, the unit in C7 should be able to see into D6, including all its hexsides and vertexes, despite the orchard in D6 blocking LOS to E6. E6 is a blind hex to to C7 because of the in-season orchard, but a Sanp Shot is allowed "if it can trace a LOS to an entire hexside (even if that hexside is part of a Blind hex)." A8.15.

23915Figure 1

In Figure one a unit in F8 can see into Adjacent hex F7, including all its hexsides and vertexes. However, F6 is a blind hex due to the plateau effect of F7. I don't see why LOS for a Snap Shot would be blocked in one but not the other.
 

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But A6.2 provides:

6.2 OBSTACLES: Each terrain type [EXC: Depressions 6.3] is defined as
to whether or not it presents an obstacle or Hindrance to LOS and, if an obstacle,
the height of that obstacle. LOS extends into or out of obstacles, but not
through them into hexes beyond the obstacle except in certain cases wherein
the target/firer are at an elevation ≥ the height of the obstacle or are adjacent to
a hexside obstacle.

View attachment 23914Figure 2

In figure 2, the unit in C7 should be able to see into D6, including all its hexsides and vertexes, despite the orchard in D6 blocking LOS to E6. E6 is a blind hex to to C7 because of the in-season orchard, but a Sanp Shot is allowed "if it can trace a LOS to an entire hexside (even if that hexside is part of a Blind hex)." A8.15.

View attachment 23915Figure 1If

In Figure one a unit in F8 can see into Adjacent hex F7, including all its hexsides and vertexes. However, F6 is a blind hex due to the plateau effect of F7. I don't see why LOS for a Snap Shot would be blocked in one but not the other.
The hexside between D6 and E6 is at level two. The orchard blocks LOS from C7. If E6 were at level one, the orchard would have no effect on LOS.
 

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Check LOS from C7 to hexside C6/C5 to test your theory and you will see VASL does not agree. I am also not sure the level of the blind hex being different should make a difference for a Snap Shot. Good discussion though.
 

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Actually, VASL is probably correct in that instance. The orchard is at level one as well as at level two, so LOS is still blocked.
 

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Perhaps but I am having trouble seeing a rule that indicates the two situations involving hexsides that are part of a blind hex should be treated differently based upon the source of the creation of the blind hex.
 
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