targetting and LOS

[d_m]

I've ported the sample DFOV implementation to C, and am trying to plug it into Angband to test with. It seems promising, although I'm a little bit nervous about getting a compatible path-finding algorithm working with DFOV.

[Marble Dice]

One problem with the lack of cover, though, is that cover is important to evasion of monsters with ranged attacks and evasion is a huge part of gameplay. That's the real reason for conical shadows.

I agree with this, and to me an ideal system would incorporate conical pillar shadows, however I'm not convinced the lack thereof will have much of an impact. DFOV does have conical shadows, but only for walls and rooms, not pillars.

I can't think of a time I've been saved by a single pillar, unless you use the pillar dance, but that would still work in DFOV. You can still use corners to lure a group of ranged attackers into melee, and corners are still tactical positions because the hockey stick would still allow you to limit your attackers to 1 melee and 2 ranged. You are more vulnerable while running down a corridor because there's 1 extra tile of enemies being able to project at you, but that's not much different than things are now.

In the current system, pillars could be an important tactical consideration but I don't feel like they ever are, Angband just doesn't have room templates that allow you to effectively utilize them to gain cover while fleeing or approaching. Maybe some of the vaults do? I can't think of any examples off the top of my head where flimsy columns would actually weaken gameplay.

[Atarlost]

I haven't played with any alternate LOS setup, but I'd expect it to come up in the rooms with a
#.
..
fill pattern and in earthquaked areas. It also means you can't hide in the pillar's shadow while luring a ranged attacker into a pillar dance.

[d_m]

Tactics like targetting hacks, sight hacks, pillar-dancing, etc, are all fallout from various game quirks (AI, LOS, FOV, etc). As such, I think it's fair to try to come up with better algorithms first and then worry about whether people's preferred hacks will still work (and in fact, I think the point of this is to get rid of some of the most flagrant/useful hacks).

[PowerDiver]

Look at the page with information on the implementation:

DFOV Implementation at RogueBasin

You can see an image which illustrates concepts behind line of sight in DFOV. The walls are arbitrary polygons, not diamonds.

I stand by my viewpoint of the model. At its heart, it is diamonds everywhere. That is what makes it so elegant. For efficiency purposes, you take hulls.

Whether you want to view ## as two adjacent diamonds, or as the stretched hexagon that is their hull, is up to you. Both give rise to precisely the same visibility blockages. That means that you can think of your rooms as having straight walls instead of the constant jagging of diamonds.

IMO it is the equivalence to diamonds everywhere that makes it clear that the overall model works cleanly.

[buzzkill]

Everything seems to get hung up on pillars. So instead of treating pillars like pillars, why not just treat them like what they are, that is 10' diameter (cylindrical/top-down circular) chunks of stone (which are very well approximated, for our purposes, by diamonds), therefore, the pillars become diamonds (along with the ends of walls, and inside corners), and LOS if established by visibility from center, to center of any given grids. I've been playing around with this in Visio (pencil and paper method), and it both produces conical shadows, both around pillars and while standing in a doorway, and preserves the hockey stick. I don't see a problem with it. Full range of vision through a pillar is broken ( @.#??????? ) but I don't think that should exist in the first place.

[Marble Dice]

I haven't played with any alternate LOS setup, but I'd expect it to come up in the rooms with a
#.
..
fill pattern and in earthquaked areas. It also means you can't hide in the pillar's shadow while luring a ranged attacker into a pillar dance.

Here's how the 25% pillars rooms would look with DFOV:

  .    ...    .                #.#
  .#   #.#   #.          ..    ...    ..
.. ..  ...  .. ..        #.#   #.#   #.#
 #. .# #.# #. .#          ...  ...  ...
  .. ....... ..            #.# #.# #.#
   #. .#.#. .#              .........
    .. ... ..          #.#.#.#.#.#.#.#.#.#
.#.#.#.#.#.#.#.#.     .....................
........@........              #@#
.#.#.#.#.#.#.#.#.     .....................
    .. ... ..          #.#.#.#.#.#.#.#.#.#
   #. .#.#. .#              .........
  .. ....... ..            #.# #.# #.#
 #. .# #.# #. .#          ...  ...  ...
.. ..  ...  .. ..        #.#   #.#   #.#
  .#   #.#   #.          ..    ...    ..
  .    ...    .                #.#

[Atarlost]

That's not as bad as I expected from the single pillar examples.

Does V have the rooms with a pillar row 1 space from the wall and an open center? What about the cross shaped rooms with a single pillar in the center?

[PowerDiver]

Everything seems to get hung up on pillars. So instead of treating pillars like pillars, why not just treat them like what they are, that is 10' diameter (cylindrical/top-down circular) chunks of stone (which are very well approximated, for our purposes, by diamonds), therefore, the pillars become diamonds (along with the ends of walls, and inside corners), and LOS if established by visibility from center, to center of any given grids. I've been playing around with this in Visio (pencil and paper method), and it both produces conical shadows, both around pillars and while standing in a doorway, and preserves the hockey stick. I don't see a problem with it. Full range of vision through a pillar is broken ( @.#??????? ) but I don't think that should exist in the first place.

If you require all of (1) symmetric, (2) passwall monsters in visible walls are targetable, (3) targeting does not go away when you cast stone-to-mud at your passwall target, and (4) all walls of a room are visible when inside the room, then you cannot have pillars casting expanding shadows. Something will break somewhere.

The problem is granularity. You want to restrict visibility to a center viewpoint, but have the obstruction fill the square, and that inconsistency leads to problems. Just think of the @ being able to range anywhere over the 10' x 10' square he occupies [which presumably he can if he can attack in any direction], and then a pillar less than 10x10 does not cast expanding shadows against the full set of viewpoints in a square.

[PaulBlay]

(4) all walls of a room are visible when inside the room

Are you including 'standing in the entrance' as inside the room there?

[PowerDiver]

Are you including 'standing in the entrance' as inside the room there?

No, I'm talking about firmly in the interior. The problem is that an expanding cone from one corner moves out to cover well into the interior of the room in the other corner.

If you think in at least 10' away from all walls you should be able to view all the walls of a square room, then (4) applies.

[buzzkill]

If you require all of (1) symmetric, (2) passwall monsters in visible walls are targetable, (3) targeting does not go away when you cast stone-to-mud at your passwall target, and (4) all walls of a room are visible when inside the room, then you cannot have pillars casting expanding shadows. Something will break somewhere.

The problem is granularity. You want to restrict visibility to a center viewpoint, but have the obstruction fill the square, and that inconsistency leads to problems. Just think of the @ being able to range anywhere over the 10' x 10' square he occupies [which presumably he can if he can attack in any direction], and then a pillar less than 10x10 does not cast expanding shadows against the full set of viewpoints in a square.

Just my opinion. I've been following this thread somewhat closely, although it's a bit over my head at times.

It's not an inconsistency. Since the pillar does not move, neither should your point of view. If you wanted to move your point of view 10' in any given direction, there's already a mechanism for that, it's called moving. Short of that, your point of view should remain stationary. Else we're approximating a warrior zig-zagging wildly down a corridor, or into and across a room. First zig to the far left side, then zag to the far right, for every 10' of forward motion. I find it much more likely he'd walk in a straight line to avoid drawing attention to himself.

If I understand you correctly, and that is an if, screw no. 4 (it not only breaks the model, but is a departure from reality). When standing in a room containing a pillar, you should not have visibility of all walls. The 10' wide pillar would obviously obstruct your vision of some portion of some wall regardless of where you stand.

EDIT: That first drawing is actually off by a hair. The 2nd form the left and 2nd from the right, in the 2nd from the top row should be visible.

[d_m]

If I understand you correctly, and that is an if, screw no. 4 (it not only breaks the model, but is a departure from reality). When standing in a room containing a pillar, you should not have visibility of all walls. The 10' wide pillar would obviously obstruct your vision of some portion of some wall regardless of where you stand.

I think #4 references a totally empty room (x and ^ are walls that I want to talk about):

#####
x...#
^...#
#...#
#...#
#@..#
#####

The issue is that if @ were to shoot at the "x" wall, the current path finding algorithm would include the "^" square in the path, and so the path would be blocked. In some of the proposed FOV ideas, you would need this path to be open to see the wall, and thus you would definitely not be able to see "x" at all.

I am pretty sure this is the issue #4 aims to address.

EDIT: incidentally, this is what targetting hacks do--they target some square far away so that the path is totally vertical until the very last square, where it swerves over.

[PowerDiver]

If I understand you correctly, and that is an if, screw no. 4 (it not only breaks the model, but is a departure from reality). When standing in a room containing a pillar, you should not have visibility of all walls. The 10' wide pillar would obviously obstruct your vision of some portion of some wall regardless of where you stand.

You misunderstood me. (4) is if you stand 10' from the wall in an *empty* square room with no pillars. Do you think you should be able to see the walls?

That's 10' into the interior, not 10' down a corridor.

[Atarlost]

Realisticly it depends what the walls are. Even walls you'll be able to see for quite a ways, but at a shallow angle you're likely to be unable to tell a wall from an unadorned doorway. If the walls are cavelike it may become difficult to distinguish walls from openings even at moderate angles.