Bridge Positions Unexpected Results

[Luft08 27]

I went through the Global Mobilization map gathering the rough position data on bridges:

eastGermanBridges = [
	[10577.8,17680.2],[10889.8,17545.4],[12102.7,17199.6],[13399.5,15948],[14312.1,15123],
	[13630.1,12722.1],[14927.9,15361.6],[14943.2,15220.9],[15658.5,14663.3],[15663.2,14166.2],
	[16256.9,12515.4],[17365.1,11464.7],[18684.4,11083.3],[14927.8,15360.4],[16192.9,15358],
	[18230.3,15977.5],[19959.8,4850.35],[18082.2,5211.08],[16399.4,6661.06],[16143.3,6951.2],
	[15553.2,8796.89],[14255.2,11924.2],[13137.8,8403.86],[12917.6,8265.83],[12582.7,7924.79],
	[13666.6,4606.77],[13870.7,4370.2],[15269.4,2432.02],[16340.1,178.734]
];

I wrote a function that takes a position and is suppose to return true if that position is at a bridge. However, it always returns false.

isOnBridge:

params["_pos"];
if((count _pos) == 2) then { _pos pushBack 0};
private _result = false;
if(isOnRoad _pos) then {
	private _nearestRoad = [_pos, 10] call  BIS_fnc_nearestRoad;
	private _roadInfo = getRoadInfo _nearestRoad;
	_result = (_roadInfo select 8);
};

_result

I was using bridge position data I gathered by hand so I figured that it wasn’t accurate enough so I wrote a function that takes the rough data and returns more precise data:

private _bridgeSeg = [];
{
	private _nearPos = _x;
	private _roadSegs = _nearPos nearRoads 50;
	
	{
		private _roadInfo = getRoadInfo _x;
		private _isBridge = _roadInfo select 8;
		if(_isBridge) then {
			_bridgeSeg pushBack (getPos _x);
		};
	} forEach _roadSegs;
} forEach eastGermanBridges;

diag_log format ["Bridge Array = %1", _bridgeSeg];

The updated data:

eastGermanBridges = [
	[10578.4,17680.9,12.4872],[10889.6,17544.5,12.8538],[12102.4,17199.3,12.5763],
	[13400.2,15949.4,12.8326],[14315,15122.7,12.4278],[13628.6,12721.3,12.5986],
	[14928.2,15360,12.1543],[14943.7,15219.7,12.9992],[15660.1,14663.1,13.0124],
	[15664.2,14165.7,14.3585],[16255.7,12514.4,13.1765],[17356.8,11455.1,14.3627],
	[17371.4,11468.7,16.0603],[17386,11482.4,12.3864],[18685.7,11083.8,14.1605],
	[14928.2,15360,12.1543],[16193.1,15347.6,14.5347],[16193.4,15367.6,15.7658],
	[18223.9,15987.5,15.8225],[18235.9,15971.4,16.2582],[19959.6,4850.25,16.6743],
	[18082.3,5211.1,14.82],[16399.5,6661.06,12.4695],[16143.4,6951.2,14.6601],
	[16156.9,6965.9,13.1921],[15543.3,8794.17,14.8643],[15562.5,8799.49,14.7014],
	[14255.7,11925.7,14.6887],[13138.5,8405,14.5256],[12920,8264.23,14.1931],
	[12581.9,7926.16,12.985],[13667,4607.53,11.6135],[13869.8,4369.87,15.0714],
	[15269.2,2432,14.7458],[16338.1,177.258,16.1915]
];

When I tested the function again it still returns false even when I pass the exact bridge position.

[pierremgi 4737]

Don't triple (even double) post!

https://forums.bohemia.net/forums/topic/235999-task-not-completing/?tab=comments#comment-3446788

https://forums.bohemia.net/forums/topic/235994-how-do-you-prevent-a-randomly-spawned-vehicle-from-spawning-on-a-bridge/?tab=comments#comment-3446752

 

 

[Luft08 27]

2 hours ago, pierremgi said:

Don't triple (even double) post!

https://forums.bohemia.net/forums/topic/235999-task-not-completing/?tab=comments#comment-3446788

https://forums.bohemia.net/forums/topic/235994-how-do-you-prevent-a-randomly-spawned-vehicle-from-spawning-on-a-bridge/?tab=comments#comment-3446752

 

 

Sorry. Although the threads deal with similar issues aimed at solving problems in the same mission they ARE different.

The first deals with a variable holding a bridge object. Only it didn't because it was being loaded with objects near the bridge. That issue was solved.

 

You do have a point about the second thread and this thread. They are similar enough that perhaps I should have just reopened the second thread and tacked on the additional information but being that I wrote code that looks like it should work but doesn't, it seemed to me to be a different issue. In retrospect it may have been too close to an earlier post.  I do apologize for the similar posts but still don't know why the code I posted fails. 

 

[Ibragim A 148]

I don't know why, but not all maps can define roads using the nearRoads command. On some maps, this command does not find anything. Therefore, it would be good to additionally search for roads with the nearestTerrainObjects:
 

_nearest_road_pos = [];

_roads1 = nearestTerrainObjects [_position, ["Road"], 50]; // nearest
_roads2 = _position nearRoads 50; // not nearest
_roads = _roads1 + _roads2;

// find nearest:
		
if (count _roads > 0) then 
	{
		_roads = _roads apply { [_x distance (_position), _x] };
		_roads sort true;

		_nearest_road_pos = position (_roads select 0 select 1);
	};

Also, it seems that isOnBridge will always return false because it uses isOnRoad, which requires z coordinates in AGL or 2D format.

if((count _pos) == 2) then { _pos pushBack 0}; // <-- delete it
if((count _pos) > 2) then { _pos = [_pos select 0, _pos select 1]}; // try it

 

[Luft08 27]

On 10/11/2021 at 8:39 PM, Ibragim A said:

I don't know why, but not all maps can define roads using the nearRoads command. On some maps, this command does not find anything. Therefore, it would be good to additionally search for roads with the nearestTerrainObjects:
 

_nearest_road_pos = [];

_roads1 = nearestTerrainObjects [_position, ["Road"], 50]; // nearest
_roads2 = _position nearRoads 50; // not nearest
_roads = _roads1 + _roads2;

// find nearest:
		
if (count _roads > 0) then 
	{
		_roads = _roads apply { [_x distance (_position), _x] };
		_roads sort true;

		_nearest_road_pos = position (_roads select 0 select 1);
	};

Also, it seems that isOnBridge will always return false because it uses isOnRoad, which requires z coordinates in AGL or 2D format.

if((count _pos) == 2) then { _pos pushBack 0}; // <-- delete it
if((count _pos) > 2) then { _pos = [_pos select 0, _pos select 1]}; // try it

 

Thanks, I ended up using:

params["_pos"];

private _result = false;
private _pos2D = [_pos select 0, _pos select 1];
private _nearestRoad = [_pos2D, 5] call  BIS_fnc_nearestRoad;
if (!(_nearestRoad isEqualTo objNull)) then {
	private _roadInfo = getRoadInfo _nearestRoad;
	_result = (_roadInfo select 8);
};
_result

It doesn't tell me if the EXACT position is a bridge but does tell me if the nearest road within 5m of the specified position is a bridge.  Close enough, I think.

[Ibragim A 148]

BIS_fnc_nearestRoad does not return position, function returns road object. Therefore, you just need to get the position of this _nearestRoad.

_result = [false, objNull];
//...
_bridgePos = position _nearestRoad;
_result = [(_roadInfo select 8), _bridgePos];

You will get return value of true and bridge position.