¶ Weather
ACSM has multiple weather systems that can be switched between when creating a race.
¶ Stock AC Weather
The stock AC weather installation is the most simple, and does not require your drivers to install any client side software.
Stock AC weather does have some noteworthy limitations:
- Start Time can only be set between 8am and 6pm
- Start Time can not be configured per-weather
- Weather transitions are possible, but instant
- You cannot activate any sort of visual rain
- It's generally more basic and does not look as good as the other systems
The basic settings for weather are all described in the race form itself:
¶ CSP/Sol Integration
If you are hosted with emperorservers.com Sol weathers come pre-loaded to your server, so you can skip this first paragraph!
In order to activate CSP/Sol Integration you must first upload the Sol weather graphics presets to your server. You can do this by going to the Content -> Weather page, clicking the Upload Weathers tab then uploading your Sol weathers from steamapps\common\assettocorsa\content\weather (for example the sol_12_fog folder), you can upload multiple weathers at once with drag and drop.
CSP/Sol Integration can be activated on the server by turning on the "Custom Shaders Patch/Sol Integration" switch at the top of the Weather section of any race form. In order for this to work drivers must install Content Manager, Custom Shaders Patch (can be installed via Content Manager as well) and Sol. All of these are developed by other great independent developers from the community who keep AC kicking, please consider supporting them for their hard work.
A driver without the above content installed will still be able to connect to the server, but the weather will be completely static for them and will not match what the other drivers are seeing.
CSP/Sol integration adds the following features:
- Full 24 hour time is possible
- Improved visuals when compared to stock AC weather, and a wider set of graphics presets to choose from
- Start Time can be set per weather, the date can also be set, which will change sunrise/set times and optionally some other seasonal effects
- Visual rain can be activated via CSP Extra Options, but will not be activated automatically (CSP rain will only work with certain versions of CSP, which are only available via the paid version from Patreon at the time of writing - 2022/05/04)
But it does have the following limitations:
- Weather transitions are possible, but instant
- When moving to a new session the time of day may take some time to "stabilise", with the time of day rapidly changing for all drivers. We recommend setting "Wait Time" to at least 120 seconds to stop this from ruining the start of a race.
¶ CSP Weather Transitions
CSP Weather Transitions are a more recent extension of the CSP weather system that allows for smooth transitions between weathers. CSP Weather transitions also allow for smooth transitions between different levels of rain, temperatures, wind speeds and wind directions.
In order to activate this you must first activate CSP/Sol Integration as described above, then turn on the "Use CSP Weather Transitions" switch. Now a new "CSP Weather Transition Duration" setting will appear, which lets you control the length of the transitions betweene each configured weather for a session.
In order to see proper transitions drivers must be running a recent version of CSP, and in order to see rain effects they must be using a rain-enabled version of CSP, which are only available via the paid version from Patreon at the time of writing - 2022/05/04. Again drivers without CSP will see completely static weather for the entire session.
CSP Weather Transitions have all the features and benefits of CSP/Sol integration, and add the following:
- Weather transitions are smooth, and can be controlled by the event configuration
- Time of day does not need time to stabilise when moving to a new session
- Visual rain will be automatically activated if a graphics preset with rain is selected, and the server will transition to/from rain as appropriate. You can also control the "Track Wetness" manually if you'd like in each weather preset box, allowing for custom scenarios (such as wet conditions with no rain).
With transitions enabled the session start time of the first configured weather (per session) will be used. All other session start times will be ignored.
If enabled then the "Session Start Date/Time" input will be converted from UTC to the timezone of the selected track (using the Geo Tag location of the track) by CSP. That means you need use a time zone converter to find the correct UTC time to enter here. Also if a track has no Geo Tags defined each user may see a different time of day. Unfortunately we have no control over this behavior.
When using CSP Weather Transitions we highly recommend setting the Weather FX Weather script in Content Manager to either
Default implementationorPure. Using theSolscript will cause the game to hang briefly whenever a transition starts.
If using ptracker with CSP Weather Transitions active we suggest using a chat filter to exclude messages from CSP, such as:
ACP:|PLP:|\$CSP0:. This example will also filter messages from ACP and PLP.
¶ CSP Weather Transitions (Weighted Random)
The weighted random system uses the CSP transitions system as described above, but instead of allowing the admin to manually define the length and order of the weather presets a weather plan is randomly generated for each session, based on the weightings given to each weather slot.
¶ What is randomly decided and how?
The weighted random system automatically generates these values:
- Number of Weather slots (based on session length)
- Weather preset for each slot (based on weighting given in event form)
- The duration of each slot (based on session length)
- The duration of each transition (based on session length)
Every value can vary between fixed minimum and maximum values based on weighting or session length.
The system uses a graphing function to build a set of weightings, deciding what values are most likely to be selected between a defined minimum and maximum:
Where the variables in that equation are:
a: maximum lengthd: minimum lengthc: midpointb: ratio, currently fixed by ACSM, lower values increase "randomness" by flattening the graphx: incremented fromdtoa, with the weighting of each value being stored
For duration the minimum is 1 minute and the maximum is event length/4, but no lower than 5 minutes.
For transition duration the minimum is 3 minutes and the maximum is event length/5, but no lower than 4 minutes.
Please note that each weather preset can be selected multiple times in a session, to give an example if you had "clear" with a low weighting, "overcast" with a medium weighting and "drizzle" with a high weighting as weather presets in your event you may end up with:
"overcast" -> "drizzle" -> "drizzle" -> "drizzle" -> "clear"
Then the next session may be:
"drizzle" -> "overcast" -> "overcast" -> "drizzle" -> "drizzle"
¶ Minimum Duration/Minimum Transition Duration
Available from v2.3.11
These options allow an admin to specify minimum durations for a weather preset when using the weighted random system. The durations may be higher than this given value, but not lower.
An example of when you may want to use this is for a preset that has rain (with physics) configured, in that scenario the automatic system may sometimes generate a transition that is faster than you may want if you want your drivers to have some warning time before needing to pit for wet tyres as the rain starts. This is especially helpful on very long tracks where the driver may be minutes away from reaching the pit lane!
¶ Conditions
¶ Weather Conditions
As well as the main weather settings you can control some of the conditions, such as temperature, wind and track grip, in more detail.
Each weather preset has options for temperatures and wind speed/direction. Within each preset the temperature and wind is static, but will change when you transition from one weather preset to another.
Within each session the "Final" value for each of these conditions is calculated as below:
- Final Temperature Ambient = Base Temperature Ambient +- Variation Ambient
- Final Temperature Road = Final Temperature Ambient + Base Temperature Road +- Variation Road
- Wind Speed is any value between Wind Base Speed Min and Wind Base Speed Max, selected randomly
- Final Wind Direction = Wind Base Direction +- Wind Variation Direction
¶ Dynamic Track Grip
The dynamic track grip settings can be found in the Realism section of any race form, it is in some ways separate to weather but is included here as it is related.
The dynamic track grip system allows you to set a % level of grip at the start of the event, how many laps must be completed to add 1% to the grip level and how much of the gained grip in a session should be transferred to the next session in the event.
For example, with these settings:
- Session Start: 92%
- Session Transfer: 50%
- Lap Gain: 30
If the event was made up of Qualifying -> Race then the Qualifying session would start with 92% grip. Say during the session 120 laps were completed, then at the end of the session the track would have 96% grip, a gain of 4%. With Session Transfer set to 50% the Race would start with 94% grip, and would reach 100% grip after 180 laps.
¶ Live Weather
¶ Change Time of Day
By default the time of day is set by the location chosen for the Live Weather when the Live Weather option is active, but it is possible to change the time of day by adding the following to "Extra Options":
[WEATHER_FX]
TIMEZONE = -25200
LATITUDE = 34.3
LONGITUDE = 118.14
Here timezone should be the offset from UTC in seconds that you would like, so -25200 is the timezone for Los Angeles. Latitude and Longitude should be set to a location matching your time offset, so again in this example Los Angeles.
For these time offsets to work properly clients must have "Use Seasonal Adjustment" turned on in their CSP options.
¶ Rain Physics
It is possible to enable Custom Shaders Patch physics, but there are some requirements that you must meet:
- ACSM v2.2.1 or newer running on the server
- Custom Shaders Patch version 2053 or newer (2000 for non-rain physics) running on all clients
If you meet those requirements, please follow these steps when creating a race to enable custom CSP physics (including rain physics if it is raining):
- Make sure the "Enable Extra Custom Shaders Patch Options" switch on the Server Options page is turned on.
- Start creating your event.
- Set "Required Minimum CSP Version" to 2053 or higher (or 2000 for non-rain physics).
- Set "Core Options" to any option that includes both car and track physics.
- Add the following to "Extra Options":
[RAIN_PREVIEW]
INTENSITY = 1
REQUIRED = 1
WITH_PHYSICS = 1
5a. If you're using CSP Weather Transitions (or Live Weather) then the "intensity" is the maximum that the physics can reach, so you most likely want to leave it at 1, then the physics will match what you see (going from dry to wet and back again works properly). If you're not using transitions and want a fixed rain level set intensity to whatever level you would like.
¶ Configuration Example
The weather system can be a bit complicated to get used to, but it's very powerful when you know what you're doing! Let's work through a configuration example using CSP Weather Transitions from start to finish.
Let's set up an event with two sessions, qualifying and a race. In qualifying we'll set up a single weather preset, in order to make the conditions fixed for all drivers across the session. In the race we'll transition between two different weathers half way between the session, changing the graphics, temperatures and wind.
- We want to use CSP/Sol with CSP Weather Transitions, so switch on the "Custom Shaders Patch/Sol Integration" switch then the "Use CSP Weather Transitions" switch. If these switches are missing check the CSP/Sol Integration section of this page.
- Now we can start configuring options, let's set the "Time Progression Multiplier" to 4 and the CSP Weather Transition Duration to 240 seconds for a slightly accelerated time progression.
- That's it for our main weather sections, now we get to the individual weather presets, each preset has a blue outline, and we can add more weather presets using the "Add Weather" button.
- First let's use the default existing weather preset to set up the weather for our qualifying session.
- Session Start Date/Time: 04/05/2022 10:00. Morning session.
- Graphics: Clear (Sol). As we're using Sol I have selected a Sol weather preset.
- Track Wetness: Based On Weather. Leaving this on the default Based On Weather option will usually be fine, in this case we want a dry track.
- Duration: 0. We want this weather to last for our entire qualifying session, so we set the Duration to 0 to disable weather transitions from this weather.
- Sessions: Qualifying selected. This weather will only be used for the Qualifying session, so we move that session into the green section on the right.
- Base Temperature Ambient: 26. In degrees centigrade, the final ambient temperature will be static, but may be +- the value of Variation Ambient.
- Base Temperature Road: 11. The final road temperature will be static, but will be the result of Final Temperature Ambient + Base Temperature Road +- Variation Road.
- Variation Ambient/Variation Road: 1. So with this setup our Final Temperature Ambient will be from 25-27, and our Final Temperature Road will be from 35-39.
- Wind Base Speed Min: 3.
- Wind Base Speed Max: 15. Wind will be static, and any value from 3-15m/s.
- Wind Base Direction: 30. 30 degrees North East +- Wind Variation Direction.
- Wind Variation Direction: 15. Final Wind Direction may be +-15 from the Base Direction.
- Once that is done, let's use the Add Weather button to add a new weather, this is going to be the first of two weather presets that we're going to transition between during the race. I won't go through all of the options in detail again apart from those which are important to point out.
- First we need to set the Graphics, let's go for Overcast (Sol) so that the race starts cloudy and dark.
- The next important setting is Duration, say our race is 20 minutes long and we want the transition to start after ten minutes, we could set the duration to 10. It's worth noting here that the Duration is in real-world minutes, so you don't need to take the in-game time multiplier into account here.
- This weather preset is being used in the race, so we select that session.
- Let's make the temperature a little colder and the wind a bit faster when compared to qualifying.
- Now let's add our second race weather preset, click the Add Weather button a second time.
- Note: As this weather is second in the chain of weathers in the race session the "Session Start Date/Time" will be ignored, as the start time has already been set by the first weather preset configured for the session.
- Now we're going to set the Graphics to Scattered Clouds (Sol), so after ten minutes in the race session we'll transition from Overcast to Scattered Clouds, over 240 seconds.
- As we're only having two weathers in this session we can set the Duration of this second weather preset to 0, that means that the weather plan is complete when this weather is active, and we won't transition again during this session. If you want you can set a Duration here, and the weather system will loop back to the first configured weather after than duration then loop endlessly.
- This weather preset is being used in the race, so we select that session.
- Finally, we can set the temperature to be a bit higher and the wind a bit slower, as we're using CSP Transitions these values will also transition smoothly when the weather transitions.
And we're done! Here are the main settings and then all three of the weather presets I just described, starting with the main settings:
Qualifying Weather:
Race Weather 1:
Race Weather 2:
