What are the hat files?

[RaceCarRobs]

Could someone tell me what the *.hat files are and what they do?
I read that these files needed to be deleted sometimes and I would like to understand why.

 

[GTR233]

HAT extension files are cache files for GTL and GTR2 circuits.
They are synthetized from AIW+TRK+GDB : that's why the very first run of a track is longer, game builds HAT then second run is faster because game reads directly HAT cache.
So it is important to delete this HAT file whenever you modify your track files otherwise game will load cache with old settings.
On low configs it is impossible to generate this hat file with large tracks like Targa Florio and CTD : that's why HAT file is included with some tracks or patches.

 

[RaceCarRobs]

Think I have got it!

So hat files are the computer's way of pre-calculating and building a quick access database to draw the track rather than using the CPU to gather all the info from many files (which take time to load) do the calculations every frame.

I assume the hat file is optimized for size and then loaded into memory and by low config you mean computers with not much memory which cannot hold the hat info plus all the file info and have scratch pad memory to calculate all at once for the big tracks.


Also seems to indicate that it's not needed to delete hat files when installing new cars only when messing around with tracks.

Appreciate the explanation. Thankyou.