selectBestPlaces

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Introduced with Arma 2 version 1.00
  

Click on the images for descriptions

Introduced in

Game:
Arma 2
Version:
1.00

Description

Description:
Find the places with the maximum value of expression in the given area. Places can be on water. Results are sorted by value. Search pattern is randomised every command execution.

Syntax

Syntax:
selectBestPlaces [position, radius, expression, precision, sourcesCount]
Parameters:
[position, radius, expression, precision, sourcesCount]: Array -
position: Object, Position3D or Position2D
radius: Number
expression: String - Arithmetic expression. Simple expression var names containing values from 0 to 1 depending on location (see also Ambient Parameters):
  • forest
  • trees
  • meadow
  • hills
  • houses
  • sea
  • night
  • rain
  • windy
  • deadBody
  • waterDepth
  • camDepth
precision: Number
sourcesCount: Number - max results to return
Return Value:
Array - in Format [[position: Position2D, expressionResult: Number], ...]

Examples

Example 1:
myPlaces = selectBestPlaces [position player, 50, "meadow + 2*hills", 1, 5];

Additional Information

Multiplayer:
-
See also:
getEnvSoundControllergetAllEnvSoundControllersfindEmptyPositionisFlatEmptyAmbient Parameters

Notes

Only post proven facts here. Report bugs on the feedback tracker. Use the talk page or the forums for discussions.
Add New Note | How To

Notes

Posted on Jul 17, 2010 - 18:39
Rübe
see http://forums.bistudio.com/showthread.php?t=93897 for some more information (though neither official, nor complete). The most important information is the list of useable keywords for the expression which is: forest, trees, meadow, hills, houses, sea, night, rain, windy and deadBody. The keyword will be replaced by the actual value at the given sample position and thus the expression gets evaluated. For example the following expression (which returns high values in forest) "forest + trees - meadow - houses - (10 * sea)" might be transformed to 0 + 0.1 - 0.7 - 0 - (10 * 0) which is - with it's result of -0.6 - not in the forest, though there are some tree(s) around. You get the idea.
Also note that you may aswell check such an expression value at a single position by passing a low radius and a sourceCount of 1, which is often just as useful as retrieving multiple (and already sorted) positions.
Also do not underestimate the keywords night, rain or windy, for if you couple them with the other keywords, you can easily get a highly dynamic system at a very low cost. (this, btw., is how animals "choose" where and when to spawn)
Posted on Apr 3, 2014 - 16:10
ffur2007slx2_5
In ArmA3 ver 1.14 Two new expressions are available: waterDepth(0-1) and camDepth(0-1), along with three simple operators: interpolate, randomGen and factor that can be used together with expressions. E.g. p = selectBestPlaces [ position player, 500, "(2 * (waterDepth interpolate [1,16,0,1]) * ((0.1+houses factor [0.1,0.8]) * (randomGen 1 + houses)))", 1, 1]; Algorithm randomGen: randomGen A(number): randomly generate a float number from 0 - A Algorithm factor: A(number) factor [p,q] = p< A <q: [(A -p)/(q-p)] Algorithm interpolate: A(number) interpolate [p,q,r,s] = A <=p:r A >=q:s p< A <q: [(A -p)/(q-p)]*(s-r) +r

Bottom Section

Posted on June 15, 2015 - 13:27 (UTC)
Killzone Kid
precision seems to have range 0 - 100. At very low values the command is extremely slow. 100 makes it quite fast. It looks like precision is some kind of grid search size. Large chunks make the search faster but less accurate.

Resulting array is [] if sourcesCount is 0 or expression is "". In all other cases it seems that result is array of arrays of the set max count. The sole indication of successful search is expressionResult value when it is > 0.
Posted on June 4, 2017 - 20:51 (UTC)
Tankbuster
Results are sorted by value, that is, the result of the expression. They are sorted in descending order, so in the case of waterdepth, the deepest water will be found at the locations at the start of the returned array and the shallowest water will be found at the locations at the end.
Posted on September 22, 2017 - 18:39 (UTC)
Tankbuster
The sourcesCount parameter is capped to 50. Asking for any more is capped to 50.