LIDAR file format

Lidar file format

Fine resolution surface data in the form of LIDAR.

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Racer is used in professional race simulators where things often go beyond what you'd normally encounter doing mods for a racing game. One of these things is the track surface, which on the high-end can be defined using LIDAR points. LIDAR is conceptually just a big chunk of points (XYZ and sometimes color data) from which the user has to create something drivable from. Data sets are generally very large, so you may be limited to what you can process in a limited timeframe.

Note that the RLD format is currently only available in licensed versions of Racer.

Racer accepts binary Lidar files with an .RLD extension (Racer LiDar). The file format is a very simple binary file.

Part	Description
Header	char[4] RLD0 char[4] HEAD int32 points int32 triangles
Points	char[4] "VERT" points times float x,y,z
Triangles	char[4] "TRIS" triangles times int32 index[3] (indices into VERT array)
Blocks	char[4] "BLKI" int32 blocks int32 blockStart[blocks] int32 blockPoints[blocks] For example: blocks=1, blockStart[0]=0, blockPoints[0]=100 (if points=100) would define a single block. Some debugging paint functions may colorize these blocks; other than that, this part really has no function.

The points are 3D vertices, the triangles indicate which vertex (point) is used for each Lidar mesh triangle (normally use counter-clockwise ordering to get the right normal).

The blocks may need some explaining; often, the Lidar data is split into geographical parts (called 'blocks' here). This is nothing more than some metadata which is used in Racer to give different blocks different colors.

Here is an example dump extract from an actual .rld file, which contains a 81 (0x51) points and 128 triangles. The binary file can be downloaded at this link.


00000000: 52 4c 44 30 48 45 41 44 51 00 00 00 80 00 00 00   RLD0HEADQ.......
00000010: 56 45 52 54 35 5e 3c c1 9a 99 a9 40 df b0 29 43   VERT5^<....@..)C
00000020: f6 28 20 c1 a8 c6 85 40 87 b7 29 43 b6 f3 03 c1   .( ....@..)C....
00000030: 6d e7 43 40 d7 c4 29 43 33 33 97 c0 aa f1 52 3f   m.C@..)C33....R?
00000040: 6a dc 29 43 cb a1 3d c0 3d 0a 97 be b4 e8 29 43   j.)C..=.=.....)C
00000050: 5e ba 99 bf b8 1e b5 bf 1d fa 29 43 12 83 48 c1   ^.........)C..H.
00000060: 3b df 83 40 a4 b0 29 43 a2 45 2c c1 ec 51 40 40   ;..@..)C.E,..Q@@
00000070: 4c b7 29 43 31 08 10 c1 fc a9 f1 3f 5a c4 29 43   L.)C1......?Z.)C
00000080: b2 9d e7 c0 cb a1 45 3f 6f d2 29 43 d1 22 af c0   ......E?o.)C."..
00000090: d7 a3 b0 be ac dc 29 43 df 4f 6d c0 0c 02 bb bf   ......)C.Om.....
000000a0: b4 e8 29 43 39 b4 f8 bf f4 fd 24 c0 db f9 29 43   ..)C9.....$...)C
000000b0: e5 d0 54 c1 96 43 3b 40 62 b0 29 43 fe d4 38 c1   ..T..C;@b.)C..8.
000000c0: 1d 5a e4 3f 0a b7 29 43 17 d9 1c c1 1d 5a 24 3f   .Z.?..)C.....Z$?
000000d0: dd c4 29 43 2f dd 00 c1 00 00 00 bf 33 d3 29 43   ..)C/.......3.)C
000000e0: 5e ba c9 c0 0e 2d d2 bf 71 dd 29 43 8f c2 91 c0   ^....-..q.)C....
000000f0: ac 1c 32 c0 73 e8 29 43 81 95 33 c0 33 33 7b c0   ..2.s.)C..3.33{.
00000100: 9a f9 29 43 fa 7e 62 c1 44 8b cc 3f 21 b0 29 43   ..)C.~b.D..?!.)C
00000110: a2 45 46 c1 6a bc f4 3e 87 b6 29 43 4a 0c 2a c1   .EF.j..>..)CJ.*.
00000120: 1d 5a 24 bf 5a c4 29 43 0a d7 0d c1 73 68 e1 bf   .Z$.Z.)C....sh..
00000130: b0 d2 29 43 64 3b e3 c0 4e 62 38 c0 71 dd 29 43   ..)Cd;..Nb8.q.)C
00000140: b4 c8 aa c0 31 08 80 c0 b4 e8 29 43 08 ac 64 c0   ....1.....)C..d.
00000150: 0a d7 a3 c0 58 f9 29 43 f8 53 6f c1 6a bc b4 3e   ....X.)C.So.j..>
00000160: 62 b0 29 43 1b 2f 53 c1 66 66 46 bf 87 b6 29 43   b.)C./S.ffF...)C
00000170: 3d 0a 37 c1 81 95 f3 bf 9c c4 29 43 79 e9 1a c1   =.7.......)Cy...
00000180: 4a 0c 42 c0 33 d3 29 43 37 89 fd c0 b8 1e 85 c0   J.B.3.)C7.......
00000190: b2 dd 29 43 7d 3f c5 c0 4c 37 a9 c0 f0 e7 29 43   ..)C}?..L7....)C
000001a0: f4 fd 8c c0 df 4f cd c0 17 f9 29 43 d9 ce 7b c1   .....O....)C..{.
000001b0: 6d e7 5b bf 21 b0 29 43 d9 ce 5f c1 62 10 00 c0   m.[.!.)C.._.b...
000001c0: 46 b6 29 43 d9 ce 43 c1 e9 26 49 c0 5a c4 29 43   F.)C..C..&I.Z.)C
000001d0: d9 ce 27 c1 b8 1e 89 c0 f2 d2 29 43 d9 ce 0b c1   ..'.......)C....
000001e0: fc a9 ad c0 b2 dd 29 43 b2 9d df c0 3f 35 d2 c0   ......)C....?5..
000001f0: f0 e7 29 43 b2 9d a7 c0 83 c0 f6 c0 93 f8 29 43   ..)C..........)C
00000200: 39 b4 12 c1 50 8d af 40 c2 b7 29 43 21 b0 2e c1   9...P..@..)C!...
00000210: 65 19 d4 40 1a b1 29 43 a4 70 ed c0 0c 02 8b 40   e..@..)C.p.....@
00000220: 95 c5 29 43 d5 78 b5 c0 91 ed 4c 40 eb d3 29 43   ..)C.x....L@..)C
00000230: aa f1 7a c0 ae d8 03 40 28 de 29 43 0c 02 0b c0   ..z....@(.)C....
00000240: 96 43 6b 3f 2a e9 29 43 75 93 d8 be 1d 5a 64 be   .Ck?*.)Cu....Zd.
00000250: 51 fa 29 43 81 95 cf c0 39 b4 f8 3f f2 d2 29 43   Q.)C....9..?..)C
00000260: 5f 07 ae bf b5 37 a8 bf 8d f8 29 43 e4 83 06 c0   _....7....)C....
00000270: 5c 8f 1e c0 52 f8 29 43 58 a8 3d c0 ed 9e 74 c0   \...R.)CX.=...t.
00000280: 10 f8 29 43 d0 d5 6e c0 1b 9e a0 c0 dc f7 29 43   ..)C..n.......)C
00000290: ed 0d 92 c0 62 10 ca c0 8d f7 29 43 f0 a7 ac c0   ....b.....)C....
000002a0: 60 76 f3 c0 11 f7 29 43 18 95 14 bf 6b 2b f6 bd   `v....)C....k+..
000002b0: c8 f8 29 43 2c d4 39 c1 aa 60 a6 40 76 b1 29 43   ..)C,.9..`.@v.)C
000002c0: a1 f8 45 c1 f0 a7 80 40 3b b1 29 43 30 4c 52 c1   ..E....@;.)C0LR.
000002d0: 4f af 34 40 f9 b0 29 43 88 f4 5f c1 40 a4 bf 3f   O.4@..)C.._.@..?
000002e0: b1 b0 29 43 92 cb 6c c1 9c c4 80 3e f2 b0 29 43   ..)C..l....>..)C
000002f0: ba 49 79 c1 86 38 76 bf b1 b0 29 43 6b 2b 2c c1   .Iy..8v...)Ck+,.
00000300: 42 cf d0 40 b1 b1 29 43 f0 a7 84 c1 aa f1 0a c0   B..@..)C........
00000310: df af 29 43 02 2b 6d c1 d1 22 53 c0 46 b6 29 43   ..)C.+m.."S.F.)C
00000320: 25 06 51 c1 fc a9 8d c0 d7 c3 29 43 48 e1 34 c1   %.Q.......)CH.4.
00000330: 8f c2 b1 c0 b0 d2 29 43 6a bc 18 c1 23 db d5 c0   ......)Cj...#...
00000340: 35 de 29 43 1b 2f f9 c0 b6 f3 f9 c0 ae e7 29 43   5.)C./........)C
00000350: 60 e5 c0 c0 25 06 0f c1 52 f8 29 43 dd 24 06 c1   `...%...R.)C.$..
00000360: be 9f d6 40 03 b8 29 43 4e 62 22 c1 04 56 fa 40   ...@..)CNb"..V.@
00000370: 5b b1 29 43 d9 ce d3 c0 48 e1 b2 40 12 c5 29 43   [.)C....H..@..)C
00000380: 29 5c 9b c0 02 2b 8f 40 26 d3 29 43 8f c2 45 c0   )\...+.@&.)C..E.
00000390: ba da 56 40 64 dd 29 43 9a 99 a9 bf 8b 6c 0f 40   ..V@d.)C.....l.@
000003a0: 6c e9 29 43 ae 47 e1 3e 3b df 8f 3f 93 fa 29 43   l.)C.G.>;..?..)C
000003b0: 2b f6 c5 c0 66 66 0d c1 d6 f6 29 43 72 f9 8f 3e   +...ff....)Cr..>
000003c0: b1 bf 9c 3f 09 f9 29 43 bd 63 83 c1 a4 70 11 c0   ...?..)C.c...p..
000003d0: 76 b0 29 43 73 d7 1f c1 8a 1f f7 40 f2 b1 29 43   v.)Cs......@..)C
000003e0: 54 52 49 53 38 00 00 00 39 00 00 00 07 00 00 00   TRIS8...9.......
000003f0: 07 00 00 00 01 00 00 00 38 00 00 00 01 00 00 00   ........8.......
00000400: 07 00 00 00 08 00 00 00 08 00 00 00 02 00 00 00   ................
00000410: 01 00 00 00 02 00 00 00 08 00 00 00 09 00 00 00   ................
00000420: 09 00 00 00 30 00 00 00 02 00 00 00 30 00 00 00   ....0.......0...
00000430: 09 00 00 00 0a 00 00 00 0a 00 00 00 03 00 00 00   ................
00000440: 30 00 00 00 03 00 00 00 0a 00 00 00 0b 00 00 00   0...............
00000450: 0b 00 00 00 04 00 00 00 03 00 00 00 31 00 00 00   ............1...
00000460: 32 00 00 00 0c 00 00 00 0c 00 00 00 05 00 00 00   2...............
00000470: 31 00 00 00 39 00 00 00 3a 00 00 00 0e 00 00 00   1...9...:.......
00000480: 0e 00 00 00 07 00 00 00 39 00 00 00 07 00 00 00   ........9.......
00000490: 0e 00 00 00 0f 00 00 00 0f 00 00 00 08 00 00 00   ................
000004a0: 07 00 00 00 08 00 00 00 0f 00 00 00 10 00 00 00   ................
000004b0: 10 00 00 00 09 00 00 00 08 00 00 00 09 00 00 00   ................
000004c0: 10 00 00 00 11 00 00 00 11 00 00 00 0a 00 00 00   ................
000004d0: 09 00 00 00 0a 00 00 00 11 00 00 00 12 00 00 00   ................
000004e0: 12 00 00 00 0b 00 00 00 0a 00 00 00 32 00 00 00   ............2...
000004f0: 33 00 00 00 13 00 00 00 13 00 00 00 0c 00 00 00   3...............
00000500: 32 00 00 00 3a 00 00 00 3b 00 00 00 15 00 00 00   2...:...;.......
00000510: 15 00 00 00 0e 00 00 00 3a 00 00 00 0e 00 00 00   ........:.......
00000520: 15 00 00 00 16 00 00 00 16 00 00 00 0f 00 00 00   ................
00000530: 0e 00 00 00 0f 00 00 00 16 00 00 00 17 00 00 00   ................
00000540: 17 00 00 00 10 00 00 00 0f 00 00 00 10 00 00 00   ................
00000550: 17 00 00 00 18 00 00 00 18 00 00 00 11 00 00 00   ................
00000560: 10 00 00 00 11 00 00 00 18 00 00 00 19 00 00 00   ................
00000570: 19 00 00 00 12 00 00 00 11 00 00 00 33 00 00 00   ............3...
00000580: 34 00 00 00 1a 00 00 00 1a 00 00 00 13 00 00 00   4...............
00000590: 33 00 00 00 3b 00 00 00 3c 00 00 00 1c 00 00 00   3...;...<.......
000005a0: 1c 00 00 00 15 00 00 00 3b 00 00 00 15 00 00 00   ........;.......
000005b0: 1c 00 00 00 1d 00 00 00 1d 00 00 00 16 00 00 00   ................
000005c0: 15 00 00 00 16 00 00 00 1d 00 00 00 1e 00 00 00   ................
000005d0: 1e 00 00 00 17 00 00 00 16 00 00 00 17 00 00 00   ................
000005e0: 1e 00 00 00 1f 00 00 00 1f 00 00 00 18 00 00 00   ................
000005f0: 17 00 00 00 18 00 00 00 1f 00 00 00 20 00 00 00   ............ ...
00000600: 20 00 00 00 19 00 00 00 18 00 00 00 34 00 00 00    ...........4...
00000610: 35 00 00 00 21 00 00 00 21 00 00 00 1a 00 00 00   5...!...!.......
00000620: 34 00 00 00 3c 00 00 00 3d 00 00 00 23 00 00 00   4...<...=...#...
00000630: 23 00 00 00 1c 00 00 00 3c 00 00 00 1c 00 00 00   #.......<.......
00000640: 23 00 00 00 24 00 00 00 24 00 00 00 1d 00 00 00   #...$...$.......
00000650: 1c 00 00 00 1d 00 00 00 24 00 00 00 25 00 00 00   ........$...%...
00000660: 25 00 00 00 1e 00 00 00 1d 00 00 00 1e 00 00 00   %...............
00000670: 25 00 00 00 26 00 00 00 26 00 00 00 1f 00 00 00   %...&...&.......
00000680: 1e 00 00 00 1f 00 00 00 26 00 00 00 27 00 00 00   ........&...'...
00000690: 27 00 00 00 20 00 00 00 1f 00 00 00 35 00 00 00   '... .......5...
000006a0: 36 00 00 00 28 00 00 00 28 00 00 00 21 00 00 00   6...(...(...!...
000006b0: 35 00 00 00 3d 00 00 00 4f 00 00 00 40 00 00 00   5...=...O...@...
000006c0: 40 00 00 00 23 00 00 00 3d 00 00 00 23 00 00 00   @...#...=...#...
000006d0: 40 00 00 00 41 00 00 00 41 00 00 00 24 00 00 00   @...A...A...$...
000006e0: 23 00 00 00 24 00 00 00 41 00 00 00 42 00 00 00   #...$...A...B...
000006f0: 42 00 00 00 25 00 00 00 24 00 00 00 25 00 00 00   B...%...$...%...
00000700: 42 00 00 00 43 00 00 00 43 00 00 00 26 00 00 00   B...C...C...&...
00000710: 25 00 00 00 26 00 00 00 43 00 00 00 44 00 00 00   %...&...C...D...
00000720: 44 00 00 00 27 00 00 00 26 00 00 00 36 00 00 00   D...'...&...6...
00000730: 4d 00 00 00 45 00 00 00 45 00 00 00 28 00 00 00   M...E...E...(...
00000740: 36 00 00 00 50 00 00 00 3e 00 00 00 29 00 00 00   6...P...>...)...
00000750: 29 00 00 00 46 00 00 00 50 00 00 00 46 00 00 00   )...F...P...F...
00000760: 29 00 00 00 2b 00 00 00 2b 00 00 00 48 00 00 00   )...+...+...H...
00000770: 46 00 00 00 48 00 00 00 2b 00 00 00 2c 00 00 00   F...H...+...,...
00000780: 2c 00 00 00 49 00 00 00 48 00 00 00 49 00 00 00   ,...I...H...I...
00000790: 2c 00 00 00 2d 00 00 00 2d 00 00 00 4a 00 00 00   ,...-...-...J...
000007a0: 49 00 00 00 4a 00 00 00 2d 00 00 00 2e 00 00 00   I...J...-.......
000007b0: 2e 00 00 00 4b 00 00 00 4a 00 00 00 4e 00 00 00   ....K...J...N...
000007c0: 37 00 00 00 2f 00 00 00 2f 00 00 00 4c 00 00 00   7.../.../...L...
000007d0: 4e 00 00 00 3e 00 00 00 38 00 00 00 01 00 00 00   N...>...8.......
000007e0: 01 00 00 00 29 00 00 00 3e 00 00 00 29 00 00 00   ....)...>...)...
000007f0: 01 00 00 00 02 00 00 00 02 00 00 00 2b 00 00 00   ............+...
00000800: 29 00 00 00 2b 00 00 00 02 00 00 00 30 00 00 00   )...+.......0...
00000810: 30 00 00 00 2c 00 00 00 2b 00 00 00 2c 00 00 00   0...,...+...,...
00000820: 30 00 00 00 03 00 00 00 03 00 00 00 2d 00 00 00   0...........-...
00000830: 2c 00 00 00 2d 00 00 00 03 00 00 00 04 00 00 00   ,...-...........
00000840: 04 00 00 00 2e 00 00 00 2d 00 00 00 37 00 00 00   ........-...7...
00000850: 31 00 00 00 05 00 00 00 05 00 00 00 2f 00 00 00   1.........../...
00000860: 37 00 00 00 04 00 00 00 0b 00 00 00 32 00 00 00   7...........2...
00000870: 32 00 00 00 31 00 00 00 04 00 00 00 0b 00 00 00   2...1...........
00000880: 12 00 00 00 33 00 00 00 33 00 00 00 32 00 00 00   ....3...3...2...
00000890: 0b 00 00 00 12 00 00 00 19 00 00 00 34 00 00 00   ............4...
000008a0: 34 00 00 00 33 00 00 00 12 00 00 00 19 00 00 00   4...3...........
000008b0: 20 00 00 00 35 00 00 00 35 00 00 00 34 00 00 00    ...5...5...4...
000008c0: 19 00 00 00 20 00 00 00 27 00 00 00 36 00 00 00   .... ...'...6...
000008d0: 36 00 00 00 35 00 00 00 20 00 00 00 27 00 00 00   6...5... ...'...
000008e0: 44 00 00 00 4d 00 00 00 4d 00 00 00 36 00 00 00   D...M...M...6...
000008f0: 27 00 00 00 4b 00 00 00 2e 00 00 00 37 00 00 00   '...K.......7...
00000900: 37 00 00 00 4e 00 00 00 4b 00 00 00 2e 00 00 00   7...N...K.......
00000910: 04 00 00 00 31 00 00 00 31 00 00 00 37 00 00 00   ....1...1...7...
00000920: 2e 00 00 00 00 00 00 00 06 00 00 00 39 00 00 00   ............9...
00000930: 39 00 00 00 38 00 00 00 00 00 00 00 06 00 00 00   9...8...........
00000940: 0d 00 00 00 3a 00 00 00 3a 00 00 00 39 00 00 00   ....:...:...9...
00000950: 06 00 00 00 0d 00 00 00 14 00 00 00 3b 00 00 00   ............;...
00000960: 3b 00 00 00 3a 00 00 00 0d 00 00 00 14 00 00 00   ;...:...........
00000970: 1b 00 00 00 3c 00 00 00 3c 00 00 00 3b 00 00 00   ....<...<...;...
00000980: 14 00 00 00 1b 00 00 00 22 00 00 00 3d 00 00 00   ........"...=...
00000990: 3d 00 00 00 3c 00 00 00 1b 00 00 00 22 00 00 00   =...<......."...
000009a0: 3f 00 00 00 4f 00 00 00 4f 00 00 00 3d 00 00 00   ?...O...O...=...
000009b0: 22 00 00 00 47 00 00 00 2a 00 00 00 3e 00 00 00   "...G...*...>...
000009c0: 3e 00 00 00 50 00 00 00 47 00 00 00 2a 00 00 00   >...P...G...*...
000009d0: 00 00 00 00 38 00 00 00 38 00 00 00 3e 00 00 00   ....8...8...>...
000009e0: 2a 00 00 00 42 4c 4b 49 01 00 00 00 00 00 00 00   *...BLKI........
000009f0: 51 00 00 00                                       Q...

Most axis systems in Racer follow the OpenGL format. Since Lidar is most often used in high-end situations, this format follows the ISO format. Upon loading, Racer will internally convert to OpenGL format implicitly. Notice the ISO axis system is X=forward, Y=left, Z=up.

Not many changes are expected, because of the simplicity of the format. However, a 'normal' section may be added to pregenerate smoothed normals.

Although for high-end purposes you might want to directly generate RLD files, you can also create them in alternative ways.

This method uses a console command in Racer to create an RLD file from an ASE file. The steps involved:

Make sure you have the base track working (your track runs without Lidar data).

Then to make an RLD file out of an ASE file:

Create an ASE file, for example using the 'Export ASE' function in 3D Studio Max. This ASE will be converted into Lidar data, so is probably high-resolution.
Place the .ase file in data/tracks/<mytrack>/ase/surface.ase (in other words, you need to create an ase directory in your track directory, and place the ASE there).
Run a race (in Racer) with that track selected
Enter the console command 'terminal' if you would like to see the progress during converting (which may take a couple of minutes).
Then enter the console command 'lidar import'. This will convert the (probably very large) surface.ase file into data/tracks/<mytrack>/track.rld.

To test whether it worked, continue:

Enter the console command 'debug 6'; you should see, amonst others, 'Lidar tree: no Lidar data'.
Enter 'reload track'. This reloads the track and the generated track.rld file. You should see some info on the Lidar tree now (number of points, triangles etc) in the debug list.
Enter 'show lidar' to visualize the Lidar data. This quickly gives an idea whether the import worked ok.
If all looks ok, remove the ase/surface.ase file again to cleanup the track directory.

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(last updated December 30, 2014 )