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Map making: Converting to and from Nitro Pack

Posted: Sun Aug 06, 2017 1:51 pm
by Lightfoot
There are (3) main differences in map headers between Interstate '76 and Nitro Pack:

1) Byte 25 - 1 byte difference in WDEF (6f - Nitro /62 - I'76)

2) Byte 45 - 1 byte difference in WRLD (53 - Nitro / 46 - I'76)

3) Byte 182 - 13 byte difference due to HZD reference (add for Nitro / remove for I'76)

This means by simply adjusting the WDEF and WRLD values accordingly and adding or removing the HZD reference (or adding / removing null values) any map can be easily ported forward or backward while maintaining the "original authors integrity" of the files.

This is in preference to "full header replacements" which are easier but do not preserve the maps original palettes.

"FHR" involves replacing the first 350 bytes (I'76) / 363 bytes (Nitro Pack) of the header from an appropriate styled map.

(Maps in the OLDROADS and MISSING map packs are examples of "FHR" from I'76 to Nitro; Frost Mines, Day Light' Race and Nitro Rush 3a are examples of "FHR" from Nitro to Nitro to adjust the night time palette. There are currently no examples of backward ported maps.)

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All conversion from Nitro Pack to I'76 need to have their extension changed to .LVL

All conversion from I'76 to Nitro Pack need to have their extension changed to .CBT (or .RAC)

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Please do not release any ports without proper prior testing and consulting the (yet to be written) "Map Format Guide"...:

BETA:

Original text file (if available) and updated text file for the conversion in MAP TEXT FILES folder.
.TER file in ADDON
.LVL file in ADDON (for I'76)
.CBT / .RAC file in MISS8 and MISS16 (for Nitro)

Let me know if you have any questions.