Question on Slopes, Hedges and Elevation Changes

[dwardzala]

A question on the LOS affects of hedge/walls, slopes and elevation changes:

On the Stoumont Map does a unit in X28 which is upslope to U30 have LOS to U30 even though there is a hedge on the V29/W29 hexside? (I think yes as hedges are only a half-level obstacle, but upslope is 3/4 level higher than base - but I may be wrong).

Same map: does a unit in X28, which is upslope to R30 (at a base elevation 1 lower than X28) have LOS to R31 even though there are hedges on the V29/W29 and U30/V29 hexsides (I think yes again as for same reason above).

 

[jrv]

A question on the LOS affects of hedge/walls, slopes and elevation changes:

On the Stoumont Map does a unit in X28 which is upslope to U30 have LOS to U30 even though there is a hedge on the V29/W29 hexside? (I think yes as hedges are only a half-level obstacle, but upslope is 3/4 level higher than base - but I may be wrong).

Same map: does a unit in X28, which is upslope to R30 (at a base elevation 1 lower than X28) have LOS to R31 even though there are hedges on the V29/W29 and U30/V29 hexsides (I think yes again as for same reason above).

Answer is yes for both.

Now for extra credit, what about S30, R33, & R32?

JR

 

[dwardzala]

S30 would be good (same reason as R30).

I think R33 and R32 would be blocked because there is a hedge on the U31/V30 hexside which is also a slope hexside, making the hedge's base level at the same height as X28.

 

[jrv]

S30 would be good (same reason as R30).

Right.

I think R33 and R32 would be blocked because there is a hedge on the U31/V30 hexside which is also a slope hexside, making the hedge's base level at the same height as X28.

Per P2.3 (and inferring a lot), Slopes do not change the base level of the hex for most purposes. The half level obstacles still rise one half level above the base level of the hex, which will be an integer. Per P2.3, for the LOS to be affected by the level difference caused by the Slope, the LOS must begin or end in the up-slope Location. P2.3 "slopes are ignored if the LOS goes through their hex" (emphasis original). The hedge on the U31/V30 hexside does not block LOS.

JR

 

[jrv]

I think R33 and R32 would be blocked because there is a hedge on the U31/V30 hexside which is also a slope hexside, making the hedge's base level at the same height as X28.

Your answer was very interesting, BTW. I think it showed you were trying to model this problem in 3-D, which would work in the real world but not so much in ASL.

This was sort of a trick question. The LOSes from X28 to R33 and R32 are both blocked, but not due to any Slope subtlety. The Slope in X28 allows a unit in that hex to see over a crest line (or other, lower, obstacle) to lower elevation, but it doesn't change the fact that there may be blind hexes. In this case, the range from X28 to S33 (the crest line) is seven hexes, meaning that the crest line generates one blind hex. For this reason the LOS from X28 to R33 is blocked. The LOS to Q34 will be open.

The same applies to R32. I put it in to see if anyone would bite on the hillside hedge. Half-level obstacles like walls and hedges have no effect on inter-level LOS (EXC, of course, Continuous Slope). Q33 will be in LOS.

JR

 

[dwardzala]

Your answer was very interesting, BTW. I think it showed you were trying to model this problem in 3-D, which would work in the real world but not so much in ASL.

This was sort of a trick question. The LOSes from X28 to R33 and R32 are both blocked, but not due to any Slope subtlety. The Slope in X28 allows a unit in that hex to see over a crest line (or other, lower, obstacle) to lower elevation, but it doesn't change the fact that there may be blind hexes. In this case, the range from X28 to S33 (the crest line) is seven hexes, meaning that the crest line generates one blind hex. For this reason the LOS from X28 to R33 is blocked. The LOS to Q34 will be open.

The same applies to R32. I put it in to see if anyone would bite on the hillside hedge. Half-level obstacles like walls and hedges have no effect on inter-level LOS (EXC, of course, Continuous Slope). Q33 will be in LOS.

JR

Thanks for the clarification - with the hedge and slope it was a case of "over-thinking" and forgetting that slopes do not affect a hex's base level. I'm getting ready to start KGP I and I was not real comfortable with slopes before now. After this CG, I suspect I will be very comfortable with them.

 

[bennyb]

This is probably flogging a dead horse.. But isn't X28 to R31 also blocked due to the creation of a single Blind Hex?

 

[jrv]

Your answer was very interesting, BTW. I think it showed you were trying to model this problem in 3-D, which would work in the real world but not so much in ASL.

This was sort of a trick question. The LOSes from X28 to R33 and R32 are both blocked, but not due to any Slope subtlety. The Slope in X28 allows a unit in that hex to see over a crest line (or other, lower, obstacle) to lower elevation, but it doesn't change the fact that there may be blind hexes. In this case, the range from X28 to S33 (the crest line) is seven hexes, meaning that the crest line generates one blind hex. For this reason the LOS from X28 to R33 is blocked. The LOS to Q34 will be open.

The same applies to R32. I put it in to see if anyone would bite on the hillside hedge. Half-level obstacles like walls and hedges have no effect on inter-level LOS (EXC, of course, Continuous Slope). Q33 will be in LOS.

JR

This is probably flogging a dead horse.. But isn't X28 to R31 also blocked due to the creation of a single Blind Hex?

Per my previous post, yes.

JR

 

[bennyb]

Thanks JR.
I saw you mention R32 and R33, but not R31.

Cheers

 

[jrv]

Thanks JR.
I saw you mention R32 and R33, but not R31.

Cheers

my error. didn't compare hex ids carefully enough.

jr