OBD:AKVA/0x24: Difference between revisions

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{{OBD_File_Header|align=center|type=AKVA|prev=AKOT|next=BINA|name=BNV Node Array|family=Level|onistuff=akva}}
;Overview
----
This is the pathfinding grid data, linked to from the BNV chunk of an [[OBD:AKVA|AKVA]].


The example below is the grid of BNV number 32 from '''level1_Final'''.
The pathfinding grid is made of equally sized tiles and it is aligned with the x and z axis. The size of the tile and the number of tiles are along each axis are stored in the [[OBD:AKVA|BNV]]. Grid rows corespond to the x axis and grid column corespond to the z axis.
:('''chr_teleport 0 0''' gets you there, and then you can use '''chr_show_bnv=1''' and '''ai2_showgrids=1''')


The example was chosen because it's a relatively small grid (45 bytes of data) and illustrates the format completely.
A tile can have one of the following types (appearance as visible with '''ai2_showgrids=1'''):
*0 : '''clear''' (no cross)
*1 : '''nearwall''' (light green cross)
*2 : '''border1''' (lightest blue cross)
*3 : '''border2''' (lighter blue cross)
*4 : '''semipassable''' (green cross)
*5 : '''border3''' (blue cross)
*6 : '''border4''' (dark blue cross)
*7 : '''stairs''' (dark green cross)
*8 : '''danger''' (orange cross)
*9 : '''impassable''' (red cross)


The pathfinding grid is aligned with the x and z axis. The size of the grid along x and z is specified in the DAT.


The grid data is stored in strips, each strip consisting of tiles of a certain type.
;Storage
:A strip can have any length between 1 and 255 (along x), and a width of 1 (along z).
:A strip runs along x for fixed z, and can wrap around to the next z if it's longer than the grid.


Tile types are (appearance as visible with '''ai2_showgrids=1'''):
The grid is stored compressed in .raw files and it is decompressed on demand (when an AI needs to find its way through a BNV).
*0 : no cross, '''clear'''
The used compression algorithm is a form of [[wikipedia:Run-length_encoding|RLE]]:
*1 : light green cross, '''nearwall'''
:*a sequence of tiles that have the same type form a run
*2 : lightest blue cross, '''border1'''
:*a run can have a length of up to 255 tiles
*3 : lighter blue cross, '''border2'''
:*runs of length 1 are treated as any other length runs
*4 : green cross, '''semipassable'''
:*runs of up to 15 tiles (short runs) are stored in one byte:
*5 : blue cross, '''border3'''
::XY (hexadecimal, with X > 0 ) stands for a run of X tiles of type Y
*6 : dark blue cross, '''border4'''
:*runs of more than 15 tiles (long runs) are stored in 2 bytes:
*7 : dark green cross, '''stairs'''
::0Y XX (hexadecimal, with XX > 0 ) stands for a run of XX tiles of type Y
*8 : orange cross, '''danger'''
::the leading 0 is used to differentiate between short and long runs
*9 : red cross, '''impassable'''
Taken from EXE (pointer array at 0x134878 in the 1527808-byte EXE)


There's another pointer array at 0x1348A0 in the 1527808-byte EXE that goes:
*0 : '''none'''
*1 : '''floor'''
*2 : '''wall'''
*3 : '''sloped'''
*4 : '''danger'''
*5 : '''stair'''
Apparently a separate type, but possibly complementary to the one above.
*0x134878 is addressed from 0xB6745 (0xB675B links to "unknown-weight %d")
*0x1348A0 is addressed from 0xB670D (0xB6723 links to "unknown-event %d")
SFeLi, please help ^^


Strips can be stored in two ways:
;Example


;Short strips (1 to 15 tiles)
The example below is the grid of BNV number 32 from '''level1_Final'''.
:are stored as one byte
:('''chr_teleport 0 0''' gets you there, and then you can use '''chr_show_bnv=1''' and '''ai2_showgrids=1''')
:XY (hexadecimal, with X > 0 )
 
:stands for a strip of X tiles of type Y
The example was chosen because it's a relatively small grid (45 bytes of data) and illustrates the format completely.


;Long strips (1 to 255 tiles)
:are stored as two bytes
:0YXX (hexadecimal, with XX > 0 )
:stands for a strip of XX tiles of type Y
The leading zero tells you if you're looking at a long or short strip.


;Example (BNV 32 from '''level1_Final''')
:(offsets relative)
:(offsets relative) (make them absolute if you like)
{|cellspacing=0
{|cellspacing=0
{{HexRow|0x00|
{{HexRow|0x00|

Revision as of 09:36, 6 June 2008

Overview

The pathfinding grid is made of equally sized tiles and it is aligned with the x and z axis. The size of the tile and the number of tiles are along each axis are stored in the BNV. Grid rows corespond to the x axis and grid column corespond to the z axis.

A tile can have one of the following types (appearance as visible with ai2_showgrids=1):

  • 0 : clear (no cross)
  • 1 : nearwall (light green cross)
  • 2 : border1 (lightest blue cross)
  • 3 : border2 (lighter blue cross)
  • 4 : semipassable (green cross)
  • 5 : border3 (blue cross)
  • 6 : border4 (dark blue cross)
  • 7 : stairs (dark green cross)
  • 8 : danger (orange cross)
  • 9 : impassable (red cross)


Storage

The grid is stored compressed in .raw files and it is decompressed on demand (when an AI needs to find its way through a BNV). The used compression algorithm is a form of RLE:

  • a sequence of tiles that have the same type form a run
  • a run can have a length of up to 255 tiles
  • runs of length 1 are treated as any other length runs
  • runs of up to 15 tiles (short runs) are stored in one byte:
XY (hexadecimal, with X > 0 ) stands for a run of X tiles of type Y
  • runs of more than 15 tiles (long runs) are stored in 2 bytes:
0Y XX (hexadecimal, with XX > 0 ) stands for a run of XX tiles of type Y
the leading 0 is used to differentiate between short and long runs


Example

The example below is the grid of BNV number 32 from level1_Final.

(chr_teleport 0 0 gets you there, and then you can use chr_show_bnv=1 and ai2_showgrids=1)

The example was chosen because it's a relatively small grid (45 bytes of data) and illustrates the format completely.


(offsets relative)
0x00:  00 FF 00 FF 00 E1 E1 70 E1 E4 11 50 11 E4 E9 14  °NONSENSE°ASCII°
0x10:  11 30 11 14 09 11 48 79 14 11 30 11 14 79 48 39  °°°°°°°°°°°°°°°°
0x20:  24 19 48 19 64 11 50 11 64 19 48 19 24 °° °° °°  °°°°°°°°°°°°°°°°


Here's the grid this corresponds to
(the grid's size is 26x35 as specified in the DAT)
01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35
01
02
03
04 255 tiles of type 0
05
06
07
08
09
10
11 255 tiles of type 0
12
13
14
15
16
17
18 225 tiles of type 0
19
20
21
22 14 tiles of type 1 7 tiles of type 0 14 tiles of type 1
23 14 tiles of type 4 1 5 tiles of type 0 1 14 tiles of type 4
24 14 tiles of type 9 4 1 3 t. of type 0 1 4 17 tiles...
25 ...of type 9 4 t. of type 8 7 tiles of type 9 4 1 3 t. of type 0 1 4 7 tiles of type 9 4 t. of type 8 3 t. of type 9
26 4 9 4 t. of type 8 9 6 t. of type 4 1 5 t. of type 0 1 6 t. of type 4 9 4 t. of type 8 9 4
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