This has been answered by
@The_American somwheres, think its one of his first 10 or so post.
EDIT: Maybe it was Ian.
EDIT 2: Maybe someone else will have better luck finding it, whoever posted it started it by explaining how the weather was divided up in PCars1 ... Ive looked but I cant spot it.
EDIT 3: Memory served me wrong this was said in the general discussion:
"
Hi... It's quite difficult to set up the weather system for sure.. But really didn't find any bug...but you have to learn to set it up properly..
That was in the official support forum...i recomend to read it an try it out... Hope it helps you like it did to me:
This has been posted by Elmo (written by a development weatherman) on the official forum about how the weather system is supposed to work.
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Internally weather system we have is actually quite robust in how it can receive weather forecast information.
The way it works is that you can feed it a condition and how long that condition will last for. With that information it will create a timeline that will playout. It works basically on a 24 hour clock.
Saying all that we did not expose all this functionality to the player because frankly we thought it was a little bit of overkill..
(As you all know PCars was a co-operative development and I think we forget a little how a simple menu like this can be confusing to people only buying the game anew.)
Ok so when you look at the screen the first option you can see is a menu item called weather slots
Here you can select between 1 and 4 slots.
Using these slots, the race setup will feed a weather timeline into the weather system.
Each slot represents what the weather will be at the top of every hour with slot 1 being the race start time slot 2 race start time +1 hour and so on. We repeat this cycle over a 24 hour period.
For example we setup a system with 2 weather slots one rainy one clear and the race time at 2pm.
Race setup will feed a timeline to the weather system something like this:
at 2pm weather will be rainy and it will be like that for 40 mins.
at 3pm weather will be clear and it will be like that for 50 mins ...
at 4pm weather will be rainy and it will last 53 mins...
at 5pm weather will be clear and it will last 35 mins ..
What this will do is when you start the race it will be raining and will so for the first 40mins.
Then at 2:40pm the weather will start to clear up and by 3pm it will be fully clear and stay that way till 3:50pm and so on.
(note the time the weather would last for is random, it was thought exposing info like this would again be too much information)
Ok so that's all simple enough. Now where it gets a little confusing
Somewhere along the development process people wanted to decouple the weather from the day and night cycle.
So for example they wanted the weather to be changing a lot but have the time of day to stay the same.
So what we did was decouple the weather timeline progression (Weather Progression) from the day night (Time Progression) .
This meant for example you could have the weather speed at 60 i.e 1 second equals 1 min but time of day at real time.
So in the example above
if we had the weather progression at realtime it would take 40 mins for the weather to start to transition to rainy.
But if we set it to 60 it would only take 40 seconds.
Then later in the project it was proposed that instead of the weather timeline being a time based thing people wanted it to happen based on how the race progressed..
So a new option was added to the Weather progression slider called "sync to race"
So the way it works is each slot would represent a proportion of the race, so if we had 2 slots they would represent the the first and second half of the race , if 4 slots then each quarter of the race.
So again taking our above example it would mean the following.
The Start of the race as always rainy and the end of the race would always be clear.
e.g If you had a 2 lap race you would start of raining and the time the leader went started the second lap the weather would be clear."