LOS Bugs?

[TeAcH]

You're joking right!?! C'Mon! haha.. yeah..you're joking. Obviously when my post is compared to Scott Clinton's, LOS has issues that are worth looking into.

TeAcH

[This message has been edited by TeAcH (edited 06-28-2000).]

[Guest Big Time Software]

Are you sure the LOS is clear? You are allowed to target units out of LOS (you just won't fire at them until they are in LOS).

But if the units were firing, then it's probably this: the underlying LOS grid doesn't match building walls perfectly (it would take too much memory and CPU time to do it more precisely). Sometimes it can be off by a bit, though the picture shown is the most extreme example I've seen. The LOS function allows for a little "play" around corners and such.

Charles

[Guest Rollstoy]

<BLOCKQUOTE>quote:</font><HR>the underlying LOS grid doesn't match building walls perfectly<HR></BLOCKQUOTE>DEJA VU! Ahhhh, how much Close Combat was always attacked for this. And now we go down that road again! Seems that the technology has indeed converged to A* path finding and Bresenham line of sight drawing. But thanks, anyway, for sharing!

Regards, Thomm

[Miles Teg]

Hi Scott,

Elevation. If there are small open ground areas seperating woods, this indicates an elevation change. In a test, I placed the woods in the same pattern. Then, noticing the small areas of open ground separating the clumps of woods, I was able to recreate a number of different combinations, where the gun has los through the open area between and even over, seemingly through the trees. At no point did the elevation changes, ever need to surpass + or - 2. For instance, two woods set to 8 and adjacent woods set to 6.

Moving on the the area where the gun is positioned, if it is +3 it will shoot over woods set at 6. If it is +2, it can shoot through the a portion of the woods set at 6. But, like I said there are a number of elevation combinations, what about the smoke?

If we look at the smoke, the epicenters of many of those do not interfere with the gun. If the center of one or more of those bursts was on top or a few meter in front, no los.

I feel the los calculations are good. You just have to beware the extreme corners of buildings. I found out the hard way in the Ardennes-Team Desobry operation.

[Splashrun]

I noticed earlier that the LOS-tool doesn't know anything about height. If you can only see the first floor of a multistory-building, it will report you can't see it.

Hence: you were invisible by the lostool, but the turret superstructure could be seen by the engine, and it killed you.

I guess..

[Guest Scott Clinton]

Miles:

Thanks for you opinion, but IMO: no, this does not explain it.

It boils down to this: the LOS was blocked BEFORE the action phase, and it was blocked after the action phase, but not DURING the action phase.

Neither the tank nor the gun moved. No more smoke was fired. So nothing MORE was added to block the LOS. As a matter of fact a case could be made that the LOS should have improved as the turn progressed and if it was clear during the action phase it surely should be clear after the action phase (do to smoke dispersion).

I knew the gun was there and that is the reason I fired two turns of smoke in front of it with my 81mm mortars. I checked before the action phase and LOS was blocked so I did not plot my tank to target the gun (I did not want it fixated on an object out of LOS for even one second). But as soon as the action phase started...the gun targeted my tank and my tank shifted to target the gun...my tank lost.

Charles said he would keep an eye on it. That is good enough for me.

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Please note the above is solely the opinion of 'The Grumbling Grognard' and reflects no one else's views but his own.

[This message has been edited by Scott Clinton (edited 06-28-2000).]

[Guest Offwhite]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Scott Clinton:

It boils down to this: the LOS was blocked BEFORE the action phase, and it was blocked after the action phase, but not DURING the action phase.<HR></BLOCKQUOTE>

You were able to check LOS from your tank after it was killed? (Please don't read this as snide or confrontational - I'm just puzzled since I didn't know you could do that )

[TeAcH]

Charles, Thanks for your reply. I'm a little bummed by your response though. I guess I was hoping that it was a bug that would go away with a tweak or a patch. But I guess it would take too much to fix it. I wonder how much more CPU and memory power would you need to fix it. The second question I have is could the building corners be invisibly exagerated just a bit to "trick" the LOS grid into making them much more accurate. In other words, create an invisible barrier around the corners of buildings that tells the computer that the wall sticks out furhter hence creating a collision field that is much closer to the drawn texture mapped wall?

I still love this game and play it all of the time, much to my wife's disappointment but I sure would like to see this tweaked a bit. Any way that a tweak like the one above or any other is possible?

Thanks

TeAcH

[chrisl]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Big Time Software:

Are you sure the LOS is clear? You are allowed to target units out of LOS Sometimes it can be off by a bit, though the picture shown is the most extreme example I've seen.

Charles<HR></BLOCKQUOTE>

I found a more extreme example last night playing a quick battle with town terrain-- there was a courtyard created by 3 big buildings corner to corner in a checkerboard pattern. Their corners touched visually, but there was (still is is-it's not over yet) an AFV parked inside the courtyard shooting out through the blocked corner.

[Guest Scott Clinton]

Offwhite, no from the crew that had bailed. And then from another Sherman right behind it.

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Please note: The above is solely the opinion of 'The Grumbling Grognard' and reflects no one else's views but his own.

[Notnowjohn]

Hate to throw even more fuel on the fire, but I just got done with a scenario in which something very strange happened along the lines of this discussion.

Seems I had a King Tiger(SS) parked in a village about 100m from a house. Couple of turns later, a Sherman presented itself just on the outskirts of town. Drawing a LOS from the Tiger to the Sherman, I noticed that the line appeared to go solidly through the corner of the building, but still gave me a clear shot(light blue line) at the Ami.

I thought that was odd, but what the hell, a shot is a shot. I targeted the Sherman and hit the go button, whereupon the Tiger proceeded to get off three quick shots, each of which impacted on the CORNER of the building and went no further. After the game turn, I checked LOS again and sure enough, was assured that I had a supposedly clean shot. Hmmmm...

Don't know what it all means, just wanted to add my 2 cents worth.

By the way, I was just curious as to wether or not my wifes divorce lawyer has gotten in touch with you guys at BTS yet?

And to be certain that you understand that the preceeding was meant in jest (and at the risk of of a good Penging) I include this:

[Ben Galanti]

I had the same thing happen recently in a quick battle. I had several shots (from both sides) impact the corner of a building, but the targetting line said it was clear (even though it drew through the corner of the buildign also)

[IntelWeenie]

I agree that this is a pain, but I take a "Full Metal Jacket" philisophical approach to it: Just because there's a building (or hedgerow) there doesn't mean there's no holes it, doesn't mean you notice that, doesn't mean someone else can't shoot you through that hole. Remember, real terrain is not perfectly square or even, especially in a combat zone. I would like the instance of LOS showing blocked before and after but not during the execution phase investigated further, though.

[TeAcH]

I see your point but with all due respect IntelWeenie, I cant be as accepting as that. Charles already confirmed that this is an issue that would have been corrected if the LOS map wasn't such of a resource hog. How much of a hog it is? Well, I was hoping for another answer.

Secondly, the buildings are not modeled with holes in them, IIRC. There has been discussion about adding partially collapsed buildings and the like in CM2, but that is not the case in this release. Also, what you are saying then is that a tank behind a hill is not safe either because there could be a culvert present allowing sighting through it. Or that grass is grown up over a hole in the hill that blows aside in the wind and thus presents no cover. Items are what they are and they should function appropriately.

These posts are in no way rants about how bad the game is. They only serve as dicussion to report possible bugs. We all love the game!

TeAcH

[This message has been edited by TeAcH (edited 06-29-2000).]

[Guest Rollstoy]

<BLOCKQUOTE>quote:</font><HR>I found a more extreme example last night - there was a courtyard created by 3 big buildings corner to corner in a checkerboard pattern. Their corners touched visually, but there was an AFV parked inside the courtyard shooting out through the blocked corner.<HR></BLOCKQUOTE>Well, chrisl, you just provided an excellent debugging setup! I think this should be corrected, maybe by making the LOS grid more 'conservative' as TeAcH suggested.

As for the line-of-fire: obviously the LOS checks are resolved on a discrete grid, while projectiles are traced as vectors and their intersection with the building polygons calculated with analog precision (?!). This makes sense, because the number of LOS checks will be orders of magnitudes higher than the number of shells in flight. <BLOCKQUOTE>quote:</font><HR>Just because there's a building (or hedgerow) there doesn't mean there's no holes it<HR></BLOCKQUOTE>But it does not mean that there is a hole in *every* building, either !

[This message has been edited by Rollstoy (edited 06-30-2000).]

[TeAcH]

Here's hoping Charles or Steve will find a few minutes to answer this topic once more. C'mon guys power down the new yacht and twin lear jets for a few minutes will ya?

TeAcH