Reverse engineering of Wipeout

[tigrou]

about CHK files : it does not seems to be PSX ram addresses, since only addressable range is 0x00000000 - 0x001FFFFF (2MB)

Most of the time, 0x80 is added in front of them. Eg : 80 44 0B 1D (so PSX address is 0x001D0B44)

I think those checkpoints are either specify directly by section index (eg : check point is at track section 142). the other values would be lap times (depending the class).

or maybe they are defined using a sphere bounding box : sphere position (XYZ = 4 * 3 bytes) + radius (2 or 4 bytes?)

The time in this game is encoded this way : 9:59.9 = (9*600+59*10+9)*5 = 29995 (maximum possible remaining lap time)

Here is one thing you can try (it helped me in my previous searches) : you start a PSX emulator (eg : psxjin r726). Then you search for the content of CHK file in RAM (for TRS they were in memory just like on the filesystem so i just had to search some bytes pattern). You can use cheat search functionality for that or use a lua script (in case of psxjin). Be aware that the byte order can be different than files on CD (big vs little endian).

Then, once you find where the data is (in memory window), you modify it directly in RAM while the game is running and you check how it change the game (in case of checkpoint it could different remaining time for checkpoint OR modify checkpoint position.

You can also (as alternative) rip your game CD to an ISO file (if not already done ), then modify the ISO directly (open it in a hexadecimal editor and search for a given byte pattern and change it). This is, anyway, a slower iteration than changing in RAM

About WAD files : yep the way you did it is how it work for most game with containers (eg : doom). Anyway you did not answer my question : are the file in the WAD binary different from other files in track folder ?

About VEW files: i give it another try yesterday : there was a minor bug. now the track culling (using VEW files) works perfectly and exactly like on the PSX. Check this branch : https://github.com/tigrouind/wipeout/tree/culling_vew. VEW files have no more secret for me. Check my post from 16/05 on first page of this topic for more info (i edited it). What is still unknown is how culling is performed on scene objects. It seems the game performs culling per object polygon ! (instead of per object). Would this information be contained in the "unknown" fields of the many polygon types the game use ?