I have re-done my weather system for GTR2 you can download it here:
http://www.gamefront.com/files/20560782/H_LweatherGenJuly2011_rarShort description of the system bellow, feel free to comment on any thing, ask questions or give suggestions:
DESCRIPTION OF GENERATION PROCESS
Enter weather details. This is done by the user.
Calculate following parameters to match current conditions in forecast (start conditions, time in weather file = 0.00):
-Start track temp +8 to -3 of user input for ambient temp.
-Start condition based on user input for current condition.
-Decide if rain will occur based on probability of rain.
-Level of rain that will occur based on level of precipitation.
-Initial on path and off path wetness based on level of rain.
Create random number to say how many changes will occur. Range of number created will be between 1 for every 15 mins (race time divided by 15) and race time divided by 3 (race time entered by user).
Generate list of condition values, one for each change that will occur. The list of conditions will meet the forecast input by the user, will not allow unrealistically fast condition changes and will use some or all of the available spread of conditions values possible given race time and difference in start condition and forecast condition (changeability). The condition list generation is done using an optimisation technique known as a ‘Genetic Algorithm’.
Once the list of conditions values has been generated, the temperature changes are determined. The temperatures will be randomly generated in the range of smallest of start and forecast temp to biggest of start and forecast temperatures. The difference from one temperature change to the next is based on the time difference between the two changes. Two times close together will not allow a large difference in temperature but two times far apart will.
The generated values are then written to the weather file. The forecast part of the system then reads the weather file and splits up the weather into 3 separate sectors, early, mid and late race forecast. The weather generation system outputs the forecast for the 3 session (and makes a forecast file) with a slight level of randomness added. The randomness means that the conditions values read can be up to 10% off. This means that it could report slight inaccuracy but not massive inaccuracy.
UPDATE - July 2011 version of weather gen system added. See post bellow for changes.
