Paths (GTA SA) - Revision history

Squ1dd13: /* File format */

2021-06-05T17:52:22Z

‎File format

Squ1dd13: /* Section 4 - Filler */

2021-06-05T17:44:07Z

‎Section 4 - Filler

Squ1dd13: Range of links

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Range of links

Squ1dd13: Wording

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Wording

Squ1dd13: /* File format */

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‎File format

Squ1dd13: Added details on core concepts

2021-06-05T17:15:27Z

Added details on core concepts

Squ1dd13: /* Purpose */

2021-06-05T16:59:56Z

‎Purpose

Squ1dd13: Reworded parts of summary

2021-06-05T16:58:26Z

Reworded parts of summary

Squ1dd13 at 16:48, 5 June 2021

2021-06-05T16:48:17Z

Squ1dd13 at 16:47, 5 June 2021

2021-06-05T16:47:43Z

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 There are several main concepts that are important for understanding the way path files work:
 * A "node" is an individual point in space which is used as an anchor for a path.
-* Full paths are created by drawing lines between nodes.
+* Paths are routes between nodes. These are traced in-game by peds and vehicles, but are typically shown in editors as graphical lines.
 * Two nodes are connected by one referencing a "link" which points to the other.
 * Most nodes link to two other nodes, one for each direction along a path, but it is possible for there to be more (such as at a junction).

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 ===Section 4 - Filler===
-This section hold data of constant size and content; its purpose is unknown. These '''768 bytes''' are filled with the repeating data pattern <code>0xFF,0xFF,0x00,0x00</code> (192x), but this can be filled with zeros as well.
+This section holds data of constant size and content; its purpose is unknown. These '''768 bytes''' are filled with 192 repetitions of the pattern <code>0xFF 0xFF 0x00 0x00</code>, but this can be filled with zeros as well.
 ===Section 5 - Navi Links===

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 ;Mem Address: These might have been pointers to path segment structures inside R*'s path compiler. Apparently they are ignored by the game and can be set to zero.
 ;Position: This is the position of the node in world coordinates. To convert the signed words to floating point values divide them by 8.
-;Link ID: Used to find adjacent nodes, the difference to the Node ID is that it counts all the links each node has.
+;Link ID: The ID of the first node this node links to. The range of linked nodes is ''link ID ≤ x &lt; (link ID + link count)'', where the link count is given by the first four bits of the flags.
 ;Area ID and Node ID: Informational data, used to connect nodes via Links. Area ID is always the same as the number in the filename, and Node ID is used to identify the node.
-;Path Width: This is used to modify the width of a path. The default value is 0 (zero). To convert the signed word to a floating point value divide it by 8 ''(unconfirmed)''.
+;Path Width: This is used to modify the width of a path. The default value is 0 (zero). To convert the signed word to a floating point value divide it by 8.
 ;Flood Fill: Flood IDs for route calculation for NPCs. For normal NPC vehicle traffic a value of 1 is used, 2 is for boats and higher values are allocated to disconnected path area segment, e.g for race tracks and other mission applications.
 ;Flags: The first 4 bits define the number of links to adjacent nodes. The other bits are used to characterize node behavior, for more information see the table below.
 ====Path Node Flags====

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 ===Section 2 - Navi Nodes===
-The second section contains additional nodes, referred to as ''navigational nodes'' (navi nodes) in this article. Each record has a size of '''14 bytes'''.
+The second section contains additional nodes. These nodes are ''navigational nodes'' (but are referred to in this article as "navi nodes" for brevity). Each record has a size of '''14 bytes'''.
 Navi nodes are used to define additional information for vehicle path segments; they are not used by ped paths. They are usually positioned between two adjacent vehicle nodes on an interpolated curve.
-There may be bugs if you don't connect navi nodes correctly. The order to connect them is to check first which of the 2 linked nodes is 'higher'. That means which one has the higher node ID or area ID. The direction of linking is allways from higher to lower node. So the target node of the navi nodes is allways the lower node. (Espacially on area boundaries!)
+There may be bugs if you don't connect navi nodes correctly. Links always go from a node with a higher area/node ID to one with a lower ID, so the target is always the lower node.
 b - INT16[2] - Position (XY), see below
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 ;Position: This is the position of the navi node in world coordinates. To convert the signed words to floating point values divide them by 8.
 ;Area ID and Node ID: These identify the target node a navi node is attached to.
-;Direction: This is a normalized vector pointing towards above mentioned target node, thus defining the general direction of the path segment. The vector components are represented by signed bytes with values within the interval <nowiki>[-100, 100]</nowiki>, which corresponds to floating point values <nowiki>[-1.0, 1.0]</nowiki>.
+;Direction: This is a normalized vector pointing towards above mentioned target node, thus defining the general direction of the path segment. The vector components are represented by signed bytes with values within the interval <nowiki>[-100, 100]</nowiki>, which corresponds to the range of floating point values <nowiki>[-1.0, 1.0]</nowiki>.
 ====Navi Node Flags====
 These are used to characterize path segment behavior, for more information see the table below.

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 * '''FLOAT''' - single precision floating point number ''(4 byte)''
-There are two main concepts that are important for understanding the way path files work:
+There are several main concepts that are important for understanding the way path files work:
-* A "node" is an individual point in space which is used as an anchor for a path. Paths are created by drawing lines through such points.
+* A "node" is an individual point in space which is used as an anchor for a path.
 * Two nodes are connected by one referencing a "link" which points to the other.
 ===Header===

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 ==Purpose==
-It is believed that these files were generated by some sort of path compiler during development of the game, and represent the processing-friendly binary data structures otherwise generated at runtime by previous versions of the game from files like <code>[[Item_Placement#PATH|paths.ipl]]</code> and related. These files are still present in SA, but unused.
+It is believed that the node files were generated by some sort of path compiler during development of the game, and represent the processing-friendly binary data structures otherwise generated at runtime by previous versions of the game from files like <code>[[Item_Placement#PATH|paths.ipl]]</code> and related. Such files are still present in SA, but are unused.
-Since the built-in path compiler has apparently been removed from the game code or at least made nonfunctional, custom tools and techniques are required to generate new paths for SA.
+Since the built-in path compiler has apparently been removed from the game code or at least made non-functional, custom tools and techniques are required to generate new paths for SA.
 Node files are streamed by the game &mdash; only the active area and those surrounding it are loaded at a time. Thus corrupt files only lead to a game crash when the player enters the specific area.

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 The 64 <code>nodes*.dat</code> files in <code>gta3.img</code> (or any other [[archive]]) contain the vehicle and ped paths and related information for [[GTA SA]]. There's a file for every 750&times;750 [[unit]] square, starting at the south-west corner (-3000, -3000) in [[Wikipedia:Row- and column-major order|row-major order]].
-However paths for planes and trains are not stored in the node-files. Nodes exist in any of the game's interiors and can only be influenced through SCM using the opcodes [[01EB|01EB]] and [[03DE|03DE]].
+Paths for planes and trains are not stored in the node files. Trains use the four <code>tracks*.dat</code> files. There are also paths for several missions and concrete cars in <code>[[Carrec|carrec.img]]</code>.
-Usually cars and pedestriants are using nodes if they are not linked to an [[SCM]] or an carrec path in any way.
+Nodes can be influenced through scripts using the opcodes [[01EB]] and [[03DE]].
 There is a [[Fastman92 Path Format|modified version]] of the path format that may be used with fastman92's Limit Adjuster, which removes or extends some of the limits that the native format imposes.
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 The separate <code>nodes*.dat</code> files in the <code>data\paths\</code> directory are ignored by the game.
-==Sections==
+==File format==
 Each file starts with a header, followed by 7 distinct sections.

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 ==Tools &amp; Scripts==
+* [[Fastman92 Path Format]]
 * {{GTAG|1093|SA Path Editor (WIP)}} by {{U|JGuntherS@NL}} &ndash; Only useful for editing existing path data.
 * {{GTAF|post|214901|3841297|Path Compiler (WIP)}} by {{U|ocram88}} &ndash; Allows to create linear ped paths by generating waypoints from inside the game.