This is part 1 of a short series chronicling the design process for an F1 Race Simulation System using AI, with the goal of creating a rapid interactive prototype.
Typically we employ a very interactive design process, with a minimum of these participants:
- Subject Matter Expert (aka Domain Expert) to talk about the problem space
- A Modeller/Designer/Developer, to refine the SME’s ideas and prompt the GPT
- Our custom GPT to build and expand the design
However, for this experiment we don’t have access to an SME – it’s all from past memory.
A few things to note before you continue reading:
- The entire exercise is about sketching and coming up with robust ideas. Complete accuracy is not the goal at this stage.
- Our custom GPT refers to “Fresnel“: our rapid prototyping tool (formally titled Fresnel Domain Model Explore). Fresnel takes Domain Model code (as you’ll see below), and runs models as interactive software prototypes. This allows us to experiment, refine, and explore scenarios, to understand how concepts fit together. You can see an example of it working on our home page.
- Note the absence of formal User Stories, Use Cases, or any UI designs. In some cases, the GPT gives us example scenarios.
- The GPT thinks the different areas are Bounded Contexts. In reality they are Subdomains, but making the distinction at this stage offers no benefits.
- Some of the names of concepts aren’t the best, but we can rename/refactor those later.
- The typos have been left in, so you can see how the AI infers the correct meaning regardless
The original ChatGPT session may be found here: https://chatgpt.com/share/67f3727b-48ac-8004-aba5-2a20a16f7768
π¬ Prompt 1:
I want to create a model for an F1 Race Simulator.
- A race is divided into a number of laps
- Each Lap is divider into 3 sectors
- Each sector has a specific physical start and end point
- The simulation needs to calculate the total time it takes for a Driver to complete each Lap
- The total time is based on a number of variables.
- Those variables include “Zero-Fuel Lap Time” (the quickest time to complete a lap, assuming it has no fuel to weight it down)
- The amount of fuel in the car, and the rate at which it burns
- The effect of tyre degradation as tyres wear down
- Tyres have a different wear rate for each Driver
- There are different types of Tyres, each with their own wear rate characteristics
- Cars that are behind other cars may be affected by “Dirty Air”, which slows the car down
- Cars that are behind other cars may be affected by “Slip-streaming”, which accelerates the car
- Cars also have boost from electrical charging
- Cars also have boost from DRS (look it up)
- To make it modular, Lap Times are calculated by iterating through a number of Calculators.
- Each Calculator deals with a different aspect (e.g. Fuel Load calculator, Tyre deg calculator)
- Each Calculator computes a Time Delta
- By summing all the deltas, and applying to the Zero Fuel Lap Time, we can compute each Lap’s time
- This is done for each Driver in a Race
Give me a high-level model that could handle this.
π« ChatGPT:
Here’s a high-level model outline for your F1 Race Simulator, aligned with Fresnel’s domain modeling approach:
πΉ Bounded Contexts
Letβs divide the domain into key bounded contexts:
- Race Management
- Driver Performance
- Tyre Management
- Fuel & Energy Systems
- Lap Time Calculation
πΉ Aggregate Roots and Entities
- Race (IAggregateRoot)
Id,VersionName[Owns] ICollection<Lap> Laps[Owns] ICollection<DriverRaceEntry> DriverEntries
- Lap (IEntity)
IdLapNumber[Owns] ICollection<Sector> Sectors
- Sector (IEntity)
IdSectorNumberStartPoint,EndPoint(positions or coordinates)
- DriverRaceEntry (IEntity)
Id[Relationship] Driver Driver// Check this for accuracy.[Owns] ICollection<LapPerformance> LapPerformances
- LapPerformance (IEntity)
IdLapNumberZeroFuelLapTimeFinalLapTime[Owns] ICollection<TimeDelta> TimeDeltas
πΉ Supporting Entities
- TimeDelta (IEntity)
IdDeltaType(enum: FuelLoad, TyreDeg, DirtyAir, etc.)DeltaSeconds
- Tyre (IEntity)
IdType(enum: Soft, Medium, Hard, etc.)BaseWearRate
- Driver (IAggregateRoot)
Id,VersionNameTyreWearProfile(e.g., multiplier on base tyre wear)
- Car (IEntity)
IdDRSEnabled(bool)ERSChargeLevelFuelLevelFuelBurnRate
πΉ Calculation Strategy (Dependencies)
- LapTimeCalculatorManager (IDomainService)
- Coordinates a set of calculators (injected)
- ITimeDeltaCalculator (Interface)
CalculateDelta(LapContext context): TimeDelta
- Implementations of ITimeDeltaCalculator
FuelLoadCalculatorTyreDegradationCalculatorDirtyAirCalculatorSlipStreamCalculatorERSBoostCalculatorDRSBoostCalculator
πΉ LapContext (IValueObject)
- Captures current state of car, tyres, track conditions for calculator input
πΉ Enumerations
DeltaType: FuelLoad, TyreDeg, DirtyAir, Slipstream, ERS, DRSTyreType: Soft, Medium, Hard
This model gives you a modular and testable way to simulate each lap per driver, calculate performance influences, and aggregate them to get the final lap time. Let me know which part you’d like to generate first!
π¬ Prompt 2:
When the Simulator runs, we need something to track the state of each Driver/Car, in each Race, for each Lap, and record the Lap Times for everyone. We also need to track the Sector Times for each too.
π« ChatGPT:
Got it β you’re describing a runtime state tracker that captures:
- Driver-Car state per Lap and Sector
- Records:
- Sector Times
- Lap Time
- Tracks evolving variables like:
- Fuel level
- Tyre wear
- ERS charge
- DRS usage
Here’s how you might model that within Fresnel:
πΉ LapSimulationState (IEntity)
Represents the state of a Driver/Car for a single Lap .
Properties:
Guid Idint LapNumberdouble TotalLapTime[Owns] ICollection<SectorSimulationState> SectorStatesdouble RemainingFueldouble TyreWearPercentdouble ERSChargeRemainingbool DRSActivated
πΉ SectorSimulationState (IEntity)
Captures the sector-level data within a Lap .
Properties:
Guid Idint SectorNumberdouble SectorTime
πΉ RaceSimulationState (IAggregateRoot)
Tracks the state of the entire simulation for one Race .
Properties:
[Key] Guid Id[ConcurrencyCheck] long Versionstring Name[Owns] ICollection<DriverSimulationState> DriverStates
πΉ DriverSimulationState (IEntity)
Holds the state for a given Driver over the whole Race .
Properties:
Guid Id[Relationship] Driver Driver// Check this for accuracy.[Owns] ICollection<LapSimulationState> LapStates
This would give you a hierarchy like:
RaceSimulationState
βββ DriverSimulationState
βββ LapSimulationState
βββ SectorSimulationState
This structure is clean, navigable in Fresnel’s UI, and aligns with aggregates and ownership rules. Would you like to generate this model now?
π¬ Prompt 3:
Lets put these latest classes in a Simulation BC, and remove the “SimulationState” suffixes from the class name
π« ChatGPT:
Perfect. Here’s how weβll structure the Simulation bounded context with the updated class names:
πΉ Simulation Bounded Context (Simulation namespace)
- RaceSimulation (IAggregateRoot)
Tracks the simulation state of the entire race.
namespace Simulation;
using Envivo.Fresnel.ModelAttributes;
using Envivo.Fresnel.ModelTypes;
using Envivo.Fresnel.ModelTypes.Interfaces;
using System.ComponentModel.DataAnnotations;
public class RaceSimulation : IAggregateRoot
{
[Key]
public Guid Id { get; set; }
[ConcurrencyCheck]
public long Version { get; set; }
public string Name { get; set; }
[Relationship(RelationshipType.Owns)]
public ICollection<DriverSimulation> DriverStates { get; set; } = [];
public override string ToString()
{
return Name;
}
}
- DriverSimulation (IEntity)
Represents a single Driverβs state across all laps in the simulation.
namespace Simulation;
using Envivo.Fresnel.ModelAttributes;
using Envivo.Fresnel.ModelTypes;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class DriverSimulation : IEntity
{
public Guid Id { get; set; }
[Relationship(RelationshipType.Has)]
public Driver Driver { get; set; } // Check this for accuracy.
[Relationship(RelationshipType.Owns)]
public ICollection<Lap> LapStates { get; set; } = [];
}
- Lap (IEntity)
Captures the state and results for one lap of a simulation.
namespace Simulation;
using Envivo.Fresnel.ModelAttributes;
using Envivo.Fresnel.ModelTypes;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class Lap : IEntity
{
public Guid Id { get; set; }
public int LapNumber { get; set; }
public double TotalLapTime { get; set; }
[Relationship(RelationshipType.Owns)]
public ICollection<Sector> SectorStates { get; set; } = [];
public double RemainingFuel { get; set; }
public double TyreWearPercent { get; set; }
public double ERSChargeRemaining { get; set; }
public bool DRSActivated { get; set; }
}
- Sector (IEntity)
Represents one sector within a lap.
namespace Simulation;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class Sector : IEntity
{
public Guid Id { get; set; }
public int SectorNumber { get; set; }
public double SectorTime { get; set; }
}
Would you like me to generate these as full .cs files next (with repositories and demo data), or is there more you’d like to tweak first?
π¬ Prompt 4:
We need the concept of one or more Pit Stops that each Driver makes during a race.
A Pit Stop may be made for a number of reasons: to change Tyres to another set, or to serve a penalty, or even to fix a piece of the car.
A proposed Pit Stop will add extra time to the Lap.
The duration of a Pit Stop is calculated in 3 stages: the Pit Entry Time, the Actual Stop Time, and the Pit Exit Time. This is because the entry speed and exit speed is mandated by regulations.
π« ChatGPT:
Awesome β here’s how we can integrate Pit Stops into the Simulation bounded context with all your requirements:
πΉ New Entity: PitStop
Purpose :
- Belongs to a
Lap(i.e., pit stop is executed during a specific lap). - Has reason(s) for the stop.
- Holds timing breakdown: Entry, Stop, Exit.
- Can be proposed or executed.
πΉ Updated Model Additions
β
PitStopReason Enum
namespace Simulation;
/// <summary>
/// The reason for making a pit stop
/// </summary>
[Flags]
public enum PitStopReason
{
None = 0,
TyreChange = 1,
Penalty = 2,
Repair = 4
}
β PitStop (IEntity)
namespace Simulation;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class PitStop : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// Reasons for the Pit Stop (can be multiple)
/// </summary>
public PitStopReason Reason { get; set; }
/// <summary>
/// Time lost entering the pit lane (due to speed limit)
/// </summary>
public double PitEntryTime { get; set; }
/// <summary>
/// Time spent stationary in the box (tyres, repair, penalty)
/// </summary>
public double ActualStopTime { get; set; }
/// <summary>
/// Time lost exiting the pit lane (due to speed limit)
/// </summary>
public double PitExitTime { get; set; }
/// <summary>
/// Total time for the pit stop (entry + stop + exit)
/// </summary>
public double TotalPitStopTime => PitEntryTime + ActualStopTime + PitExitTime;
public override string ToString()
{
return $"{Reason} - {TotalPitStopTime:0.000}s";
}
}
β
Update to Lap entity
Add a relationship to allow for zero or more PitStops during that Lap:
[Relationship(RelationshipType.Owns)]
public ICollection<PitStop> PitStops { get; set; } = [];
That gives you:
Lap
βββ ICollection<Sector> SectorStates
βββ ICollection<PitStop> PitStops
This supports both planned and executed pit stops, allows for multiple reasons, and calculates time impact explicitly.
Ready to bake these into the full code files?
π¬ Prompt 5:
We also need this concept in the Race Management BC. The problem is, we don’t know which Laps would be best suited for a Pit Stop. So we want to try different Scenarios, and somehow calculate which Laps would offer the best opportunity to pit.
π« ChatGPT:
Got it β you want to model strategic planning of Pit Stops before the simulation runs. That belongs in the Race Management bounded context and deals with Pit Stop Scenarios , i.e.:
- Trying different combinations of pit laps
- Assigning reasons and tyre selections
- Comparing total race time based on each scenario
πΉ Race Management Bounded Context
β
PitStopPlan (IEntity)
Represents a single pit stop in a planned scenario.
namespace RaceManagement;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class PitStopPlan : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// The Lap number where this stop is planned
/// </summary>
public int PlannedLap { get; set; }
/// <summary>
/// Reason(s) for this planned stop
/// </summary>
public Simulation.PitStopReason Reason { get; set; }
/// <summary>
/// The type of tyres to switch to, if any
/// </summary>
public TyreType? TyreToSwitchTo { get; set; }
public override string ToString()
{
return $"Lap {PlannedLap} - {Reason}" + (TyreToSwitchTo.HasValue ? $" to {TyreToSwitchTo}" : "");
}
}
β PitStrategyScenario (IEntity)
Represents one strategy β i.e., a list of planned stops.
namespace RaceManagement;
using Envivo.Fresnel.ModelTypes.Interfaces;
using Envivo.Fresnel.ModelAttributes;
public class PitStrategyScenario : IEntity
{
public Guid Id { get; set; }
public string Name { get; set; }
/// <summary>
/// The driver this strategy is intended for
/// </summary>
[Relationship(RelationshipType.Has)]
public Simulation.Driver Driver { get; set; } // Check this for accuracy
[Relationship(RelationshipType.Owns)]
public ICollection<PitStopPlan> PitStops { get; set; } = [];
public override string ToString()
{
return Name;
}
}
This allows:
- Multiple scenarios per driver
- Each with different lap timing , reasons , and tyre switches
- Use in tools to simulate different outcomes and compare results
Want to generate this set next, or continue refining?
π¬ Prompt 6:
When we execute a simulation, we know that other Cars will affect our Cars (e.g. due to being blocked on track, or being in dirty air, or being in clean air.
Therefore, the Simulation logic needs to split a Lap into ‘chunks’ (based on a user defined resolution).
For each chunk, each Car’s progress is calculated.
The logic will know the relative positions of cars.
The logic can decide which Calculations need to apply depending on the distance to the car in front (e.g dirty air, clean air)
Each chunk is processed in sequence, so that the relative positions of cars is maintained throughout the processing
π« ChatGPT:
That’s a great level of detail β you’re describing a time-stepped simulation , where a Lap is split into discrete chunks (like a mini-segment or snapshot), and each chunk:
- Tracks the Car’s position within the Lap
- Applies delta-time calculations (e.g., slipstream, dirty air, blocking)
- Depends on relative position to other cars
- Is processed in strict sequential order (preserving race state evolution)
πΉ Modeling Lap Progression in Chunks
Letβs add this concept into the Simulation bounded context:
β
LapChunk (IEntity)
A mini time segment within a lap used for simulation step-by-step.
namespace Simulation;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class LapChunk : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// Sequential position of this chunk within the lap
/// </summary>
public int Sequence { get; set; }
/// <summary>
/// The car's distance along the track at this point
/// </summary>
public double DistanceAlongLap { get; set; }
/// <summary>
/// The time taken for this chunk
/// </summary>
public double TimeDelta { get; set; }
/// <summary>
/// True if affected by dirty air, slipstreaming, or blocking
/// </summary>
public string Influences { get; set; } // Could also be enum/flag or breakdown in future
}
β
Update to Lap
Each Lap now holds a list of Chunks that represent fine-grained progress and influence data.
[Relationship(RelationshipType.Owns)]
public ICollection<LapChunk> Chunks { get; set; } = [];
This enables:
- Customizable simulation resolution (e.g., 10m segments, 100ms intervals)
- Accurate overtaking/blocking logic
- Step-by-step delta-time computation (via calculators)
- Potential visualization of progress and racecraft
We can also evolve LapChunk to include:
- Reference to car ahead
- Flags for DRS/ERS activation
- Flags for Track status (e.g., yellow flag, weather)
Would you like to lock this in and start generating code?
π¬ Prompt 7:
Here’s the tricky part. Race Strategists measure everything in time (e.g. delta to car in front, delta to car behind). They don’t use distance measurements. So all values and calculations need to work on a time basis.
π« ChatGPT:
Thatβs a really important insight β and it totally shifts how we model things.
Instead of using distance-based progress , your LapChunk needs to represent elapsed time , and car positions are determined by how far theyβve progressed in time , not meters.
So letβs reframe the model to reflect that:
πΉ Updated Concept: Time-Based LapChunk
β
LapChunk (IEntity)
namespace Simulation;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class LapChunk : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// Sequential chunk number within the Lap (e.g. 1, 2, 3...)
/// </summary>
public int Sequence { get; set; }
/// <summary>
/// Cumulative time from the start of the Lap, up to this chunk
/// </summary>
public double ElapsedTime { get; set; }
/// <summary>
/// Time taken for this specific chunk
/// </summary>
public double TimeDelta { get; set; }
/// <summary>
/// Breakdown or tag indicating influencing factors (e.g. Dirty Air, Clean Air, DRS)
/// </summary>
public string Influences { get; set; }
public override string ToString()
{
return $"[{Sequence}] +{TimeDelta:0.000}s (Elapsed {ElapsedTime:0.000}s)";
}
}
β Simulation Resolution Setting (for UI)
You could introduce a domain object like:
public class SimulationSettings : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// How long (in seconds) each chunk should last
/// </summary>
public double ChunkDurationSeconds { get; set; } = 0.25; // e.g. 250ms chunks
}
Then, during simulation, LapChunks are computed based on time steps:
- Calculate forward by
ChunkDurationSeconds - Apply influence logic (based on time gap to other cars, not distance)
- Update
ElapsedTimeaccordingly
β During Simulation Logic:
- At each time step:
- Compare current
ElapsedTimeof all cars - Determine delta-times between cars (ahead, behind)
- Tag influences on each chunk (e.g., βSlipstreamβ, βBlockedβ, βDirtyAirβ)
This fits how strategists think, supports replay and telemetry views, and keeps you aligned with real-world F1 analysis.
Ready to build this model into actual code? Or want to discuss how calculators would plug into it next?
π¬ Prompt 8:
An important thing about Tyre Degredation Models: Tyres designed for Dry conditions perform very differently under Wet conditions. Tyres designed for Wet conditions perform very differently under Dry conditions. We need the ability to say what the Track Conditions might be (rain could start or stop at any time, and the track could go from wet to try). This needs factoring into the logic.
π« ChatGPT:
Thatβs a critical piece of realism β you’re capturing:
- Track Conditions that evolve over time (wet to dry, dry to wet)
- Tyre types that behave differently depending on the current track state
- The need for simulation logic (especially tyre degradation and grip models) to adapt based on current weather and surface conditions
Hereβs how we can model this:
πΉ TrackCondition Enum
namespace Simulation;
/// <summary>
/// Represents the grip and weather condition of the track
/// </summary>
public enum TrackCondition
{
Dry,
Damp,
Wet,
Intermittent // e.g. drying or light drizzle
}
πΉ TrackSurfaceState (IEntity)
This represents the trackβs condition over time, aligned with LapChunk or time progression.
namespace Simulation;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class TrackSurfaceState : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// Time during the race where this condition applies
/// </summary>
public double ElapsedRaceTime { get; set; }
/// <summary>
/// Track condition at that time
/// </summary>
public TrackCondition Condition { get; set; }
public override string ToString()
{
return $"{Condition} @ {ElapsedRaceTime:0.0}s";
}
}
πΉ RaceSimulation Update
Add a list of track condition changes to the RaceSimulation:
[Relationship(RelationshipType.Owns)]
public ICollection<TrackSurfaceState> TrackConditions { get; set; } = [];
πΉ How This Integrates Into Simulation Logic
Each LapChunk can:
- Look up current
TrackConditionusing itsElapsedTime - Combine that with the Tyre Type on the car
- Delegate to the appropriate TyreDegradationCalculator (with strategy logic like: slicks on wet track = rapid deg + time loss)
This sets the stage for rich simulation logic β even modelling risk (e.g., driver spins due to wrong tyre choice under poor conditions).
Would you like to go ahead and bake this into the code too?
π¬ Prompt 9:
That’s a good point: if a driver spins, we would need to add ‘Driver Recovery Time’ as a time delta
π« ChatGPT:
Exactly! That fits perfectly with the modular LapTime calculation strategy you already have. A Driver Spin or Incident introduces an additional TimeDelta β just like fuel load, tyre wear, or DRS boost β but only triggered under certain conditions.
Hereβs how we can model that:
πΉ DeltaType Enum Update
Add a new value:
public enum DeltaType
{
FuelLoad,
TyreDeg,
DirtyAir,
Slipstream,
ERS,
DRS,
DriverRecovery // π New!
}
πΉ DriverRecoveryCalculator (ITimeDeltaCalculator)
This calculator would:
- Look at current
TrackCondition - Compare with
TyreTypeand current grip level - Possibly factor in
DriverSkillorRiskTaking(future extensibility) - If a spin or slide is detected β return a
TimeDeltawithDeltaType.DriverRecovery
public class DriverRecoveryCalculator : ITimeDeltaCalculator
{
public TimeDelta CalculateDelta(LapContext context)
{
var currentCondition = context.TrackCondition;
var tyre = context.CurrentTyres;
bool isMismatched =
(tyre.Type == TyreType.Slick && currentCondition != TrackCondition.Dry) ||
(tyre.Type == TyreType.Wet && currentCondition == TrackCondition.Dry);
if (isMismatched)
{
var recoveryTime = 2.5; // example penalty for spinning or correcting
return new TimeDelta
{
DeltaType = DeltaType.DriverRecovery,
DeltaSeconds = recoveryTime
};
}
return new TimeDelta
{
DeltaType = DeltaType.DriverRecovery,
DeltaSeconds = 0
};
}
}
πΉ Benefits
- Fully encapsulated logic
- Easy to test or swap out recovery behavior
- Can later evolve to model yellow flags, safety car triggers, or spin animations
Would you like this DriverRecoveryCalculator added to the set of generators when we create your simulation engine code?
π¬ Prompt 10:
Would the DriverRecoveryCalculator be added only when needed, or as a constant? (I’m thinking of performance)
π« ChatGPT:
Great question β and you’re totally right to consider performance and modularity.
Here are two solid strategies, depending on your goals:
β
Option 1: Always Add (but return 0s when not needed)
Pros:
- Simpler setup
- Every LapChunk is processed consistently
- Keeps the calculator chain predictable
Cons:
- Slight overhead even when not needed (though small if implemented efficiently)
When to use:
Good for early stages, debugging, or simulations that need full traceability per chunk.
β Option 2: Add Conditionally Based on Simulation Settings
You introduce a setting or strategy config that determines which calculators to use:
public class SimulationSettings : IEntity
{
public Guid Id { get; set; }
public bool EnableDriverRecoveryChecks { get; set; } = true;
}
In your LapTimeCalculatorManager, you check this:
if (_settings.EnableDriverRecoveryChecks)
{
_calculators.Add(new DriverRecoveryCalculator());
}
Pros:
- Scalable β load only the logic you need
- Avoids unnecessary computation
- Allows for “lightweight” vs “full-fidelity” simulations
When to use:
Ideal for larger simulations or when doing strategy planning at scale (e.g., thousands of scenarios).
β Recommended Approach:
Start with Option 2 (configurable) using a SimulationSettings object or similar. That gives you the best of both worlds β performance and flexibility.
Would you like me to model that SimulationSettings with toggles for calculators and chunk resolution too?
π¬ Prompt 11:
Yes, add that to Simulation Settings. What else might we need in there?
π« ChatGPT:
Nice β hereβs a starter set of properties for your SimulationSettings, capturing control, performance, and realism . You can always expand it, but this will give you solid coverage:
β SimulationSettings (IEntity)
namespace Simulation;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class SimulationSettings : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// Time resolution of the simulation in seconds (e.g. 0.25 = 250ms per chunk)
/// </summary>
public double ChunkDurationSeconds { get; set; } = 0.25;
/// <summary>
/// Whether to consider tyre degradation in lap time calculation
/// </summary>
public bool EnableTyreDegCalculation { get; set; } = true;
/// <summary>
/// Whether to consider fuel load and burn rate
/// </summary>
public bool EnableFuelLoadCalculation { get; set; } = true;
/// <summary>
/// Whether to include DRS boosts (if available)
/// </summary>
public bool EnableDRSBoost { get; set; } = true;
/// <summary>
/// Whether to include ERS (electrical boost) impact
/// </summary>
public bool EnableERSBoost { get; set; } = true;
/// <summary>
/// Whether cars are affected by dirty air from the car in front
/// </summary>
public bool EnableDirtyAirEffect { get; set; } = true;
/// <summary>
/// Whether cars gain time from slipstreaming (aero tow)
/// </summary>
public bool EnableSlipstreamEffect { get; set; } = true;
/// <summary>
/// Whether to check for spins or recovery due to mismatched tyre/track conditions
/// </summary>
public bool EnableDriverRecoveryChecks { get; set; } = true;
/// <summary>
/// Whether to enable pit strategy simulation (adds proposed pit stops to logic)
/// </summary>
public bool EnablePitStrategySimulation { get; set; } = true;
public override string ToString()
{
return $"Resolution: {ChunkDurationSeconds:0.000}s, Effects: Tyre={EnableTyreDegCalculation}, Fuel={EnableFuelLoadCalculation}, DRS={EnableDRSBoost}";
}
}
π‘ Future expansions you might consider:
RandomSeedfor stochastic elements (e.g. random weather, failure chance)WeatherForecastMode: Predicted vs ActualEnableSafetyCar,EnableRedFlagsMaxConcurrentSimulations(if you go parallelized later)
Would you like me to generate this one now? Or wait and do a batch generation when weβre ready?
π¬ Prompt 12:
I don’t like that design – it’s not extensible. I would prefer that when a new Calculator is added, the settings can somehow accommodate the flags
π« ChatGPT:
Excellent instinct β you’re right. A fixed list of booleans tightly couples SimulationSettings to specific calculators, which becomes fragile and non-extensible as the number of calculators grows.
Letβs improve this by introducing a more extensible and pluggable design , where:
- Each Calculator declares its own unique ID or name
SimulationSettingsholds a list of enabled calculator names- You can add or remove calculators dynamically (even user-defined ones)
- New calculators donβt require changes to the settings class
πΉ Updated Design: Extensible Calculator Control
β
SimulationSettings (Extensible Version)
namespace Simulation;
using Envivo.Fresnel.ModelTypes.Interfaces;
public class SimulationSettings : IEntity
{
public Guid Id { get; set; }
/// <summary>
/// Time resolution of the simulation in seconds (e.g. 0.25 = 250ms per chunk)
/// </summary>
public double ChunkDurationSeconds { get; set; } = 0.25;
/// <summary>
/// The list of enabled calculators by name
/// </summary>
public ICollection<string> EnabledCalculators { get; set; } = [];
/// <summary>
/// Check whether a calculator with the given name is enabled
/// </summary>
public bool IsEnabled(string calculatorName)
{
return EnabledCalculators.Contains(calculatorName);
}
public override string ToString()
{
return $"Ξt={ChunkDurationSeconds}s, Enabled: {string.Join(", ", EnabledCalculators)}";
}
}
β Each Calculator Now Defines Its Name
public interface ITimeDeltaCalculator
{
string Name { get; }
TimeDelta CalculateDelta(LapContext context);
}
Example:
public class TyreDegradationCalculator : ITimeDeltaCalculator
{
public string Name => "TyreDegradation";
public TimeDelta CalculateDelta(LapContext context)
{
...
}
}
β LapTimeCalculatorManager Uses Settings Dynamically
foreach (var calculator in _allAvailableCalculators)
{
if (_settings.IsEnabled(calculator.Name))
{
_activeCalculators.Add(calculator);
}
}
β Benefits:
- Zero changes needed to
SimulationSettingswhen new calculators are introduced - User or UI-configurable via list
- Works great for plugins or modules
- Easily supports future toggles like debug/test-mode calculators
Would you like this version of SimulationSettings modeled and generated?
π¬ Prompt 13:
The DriverRecoveryCalculator needs to factor in the probability of a spin, for example. Just because a driver has tyres that don’t match the track, doesn’t mean they will definitely spin. The drivers are experts, who may spin.
π« ChatGPT:
Exactly β and that nuance is important to make the simulation feel realistic.
Instead of triggering a spin deterministically , we introduce a probability-based decision :
- The mismatch between tyre and track increases the likelihood of a spin.
- Each driver might have different levels of skill , risk tolerance , or car control , which affect this probability.
- A random value determines if a spin occurs in a given chunk.
πΉ New Concept: SpinProbabilityModel
This can be:
- A stateless service (
IDomainDependency) - Reused across chunks and drivers
- Injectable into
DriverRecoveryCalculator
β
Sample Interface: ISpinProbabilityModel
public interface ISpinProbabilityModel : IDomainDependency
{
/// <summary>
/// Returns true if the driver spun under current track/tyre conditions
/// </summary>
bool ShouldSpin(LapContext context);
}
β Simple Implementation
public class DefaultSpinProbabilityModel : ISpinProbabilityModel
{
private readonly Random _rng = new();
public bool ShouldSpin(LapContext context)
{
var isWetTrack = context.TrackCondition != TrackCondition.Dry;
var isSlickTyre = context.CurrentTyres.Type == TyreType.Slick;
if (!isWetTrack || !isSlickTyre)
return false;
var riskFactor = 0.05; // 5% default risk of spin if slicks on wet
// Future: Could be adjusted by driver skill, tyre wear, chunk speed
return _rng.NextDouble() < riskFactor;
}
}
β
In DriverRecoveryCalculator
Inject the model:
private readonly ISpinProbabilityModel _spinModel;
public DriverRecoveryCalculator(ISpinProbabilityModel spinModel)
{
_spinModel = spinModel;
}
public TimeDelta CalculateDelta(LapContext context)
{
if (_spinModel.ShouldSpin(context))
{
return new TimeDelta
{
DeltaType = DeltaType.DriverRecovery,
DeltaSeconds = 3.0 // e.g. recovery time after spin
};
}
return new TimeDelta
{
DeltaType = DeltaType.DriverRecovery,
DeltaSeconds = 0
};
}
This gives you realistic, non-deterministic driver errors , influenced by tyre-track mismatch, and extensible to include driver skill in the future.
Want me to generate this setup, including the spin model interface and default implementation?
π¬ Prompt 14:
Not all properties need public setters. Setters that would be updated manually (by a person) remain public, but properties updated by code logic should be marked as Internal. Which ones can be marked as Internal?
π« ChatGPT:
Great principle β Fresnel respects .NET scoping rules, so using internal setters helps guide who controls what in your domain logic.
Letβs apply that rule to your current model. Hereβs a breakdown of which properties should likely be internal set (i.e., updated by simulation logic only), and which should remain public set (editable in the UI):
β Lap
public int LapNumber { get; set; } // UI editable if manually configuring
public double TotalLapTime { get; internal set; } // β
set by simulation logic
public double RemainingFuel { get; internal set; } // β
simulation tracks fuel
public double TyreWearPercent { get; internal set; } // β
updated over time
public double ERSChargeRemaining { get; internal set; } // β
based on usage
public bool DRSActivated { get; internal set; } // β
toggled dynamically
β LapChunk
public int Sequence { get; internal set; } // β
assigned during chunk generation
public double ElapsedTime { get; internal set; } // β
updated by simulator
public double TimeDelta { get; internal set; } // β
calculated by logic
public string Influences { get; internal set; } // β
populated by logic
β PitStop
public double PitEntryTime { get; internal set; } // β
rule-driven
public double ActualStopTime { get; internal set; } // β
rule-driven
public double PitExitTime { get; internal set; } // β
rule-driven
public double TotalPitStopTime => PitEntryTime + ActualStopTime + PitExitTime; // read-only calc
β TrackSurfaceState
public double ElapsedRaceTime { get; set; } // UI-settable, represents track change point
public TrackCondition Condition { get; set; } // UI-settable or calculated
β
SimulationSettings
Leave all setters public so users can adjust settings.
β
DriverSimulation , RaceSimulation , Sector , PitStopPlan , PitStrategyScenario
These are mostly structural/configuration β leave them public unless there’s a clearly internal-only property.
Let me know if you want a pass over the rest of the model to apply these internally β or want a helper doc to track which props are logic-updated vs UI-edited.
π¬ Prompt 15:
All internal properties need the [JsonInclude] attribute above the property definition
π« ChatGPT:
Perfect β yes, Fresnel uses JSON (and reflection) under the hood, and marking internal properties with [JsonInclude] ensures they are correctly serialized and shown in the UI even though they aren’t publicly settable.
Hereβs how you’d apply it:
β Example: Updated Lap Entity
using System.Text.Json.Serialization;
public class Lap : IEntity
{
public Guid Id { get; set; }
public int LapNumber { get; set; }
[JsonInclude]
public double TotalLapTime { get; internal set; }
[JsonInclude]
public double RemainingFuel { get; internal set; }
[JsonInclude]
public double TyreWearPercent { get; internal set; }
[JsonInclude]
public double ERSChargeRemaining { get; internal set; }
[JsonInclude]
public bool DRSActivated { get; internal set; }
...
}
Wherever you have internal set, you should add [JsonInclude] just above it β otherwise those fields wonβt show up in the Fresnel UI or wonβt deserialize properly during restores or transitions.
Would you like me to apply this across all logic-managed properties in the code when we generate them?
π¬ Prompt 16:
Yes, but don’t generate code yet
π« ChatGPT:
Got it β Iβll make sure that when we generate the code:
- All
internal setproperties (i.e., those updated by logic, not by users) will be decorated with[JsonInclude] - This applies across Lap , LapChunk , PitStop , and any other simulation-driven entities
We’ll hold off on code generation until you’re ready. Just say the word when you want to build the classes or dive into another area of the domain!
π¬ Prompt 17:
We’ll need an Overtake Calculator: when a driver is catching another and within overtaking distance, they may take a chance. Some drivers are more likely to overtake. However, some tracks have bends that limit overtaking (and some bends have zero chance of overtaking). Some may attempt an overtake, but then back off.
On track straights, the likelihood over overtaking can depending on the length of the straight.
π« ChatGPT:
This is π₯ β now we’re into racecraft and tactics . Here’s how we can model a solid, extensible Overtake Calculator that considers:
- Driver aggressiveness or risk profile
- Proximity to the car ahead (in time)
- Track segment characteristics (bend vs straight, overtaking probability)
- DRS availability
- The chance of aborted attempts
πΉ Core Concepts
β TrackSegment (IEntity)
Segments of the track β used by simulation to decide overtaking opportunity.
public class TrackSegment : IEntity
{
public Guid Id { get; set; }
public string Name { get; set; }
/// <summary>
/// Whether this segment is a straight, bend, or complex section
/// </summary>
public TrackSegmentType SegmentType { get; set; }
/// <summary>
/// Relative overtaking difficulty (0 = never, 1 = easy)
/// </summary>
public double OvertakeChance { get; set; }
/// <summary>
/// Length of segment in meters (only relevant for straights)
/// </summary>
public double LengthMeters { get; set; }
public override string ToString() => $"{Name} ({SegmentType})";
}
β TrackSegmentType Enum
public enum TrackSegmentType
{
Straight,
Bend,
Complex
}
πΉ Overtake Calculator
β
OvertakeCalculator : ITimeDeltaCalculator
- Uses
LapContextto determine: - Distance to car ahead (in time )
- Current
TrackSegment - Driver overtake tendency / aggression
- Availability of DRS
- Computes if an overtake is attempted
- If successful β time gain
- If aborted β possible time loss
- If blocked β small loss, no pass
πΉ Dependencies to support this
IOvertakeProbabilityModel(like the spin model):- Inputs: driver style, track segment, relative delta, DRS, tyre state
- Output: AttemptType (Successful, Failed, Aborted, NoAttempt)
public enum OvertakeAttemptResult
{
NoAttempt,
AttemptedAndPassed,
AttemptedAndAborted,
Blocked
}
πΉ Example Scenario:
- Driver A is 0.6s behind Driver B
- They’re on a straight of 650m with DRS active
- Driver A has high aggression
- Segment has
OvertakeChance = 0.75 - Model returns:
AttemptedAndPassed β -0.4s
Would you like to define that IOvertakeProbabilityModel interface next? Or discuss how TrackSegments are attached to chunks or laps?
π¬ Prompt 18:
Show me options for attaching TrackSegments
π« ChatGPT:
Nice β you’ve got a few clean and extensible options for attaching TrackSegments to the simulation timeline. Each approach gives a different tradeoff between fidelity, simplicity, and simulation control.
β Option 1: Attach TrackSegment to LapChunk (Fine-Grained Control)
[Relationship(RelationshipType.Has)]
public TrackSegment Segment { get; set; } // π Assigned per chunk
Pros:
- Most accurate: you know exactly which segment each chunk is in
- Enables segment-specific logic (DRS zones, corner exits, etc.)
- Easy to track overtaking, spins, etc. by segment
Cons:
- More data to manage (each chunk needs a segment ref)
- Requires segmentation of lap when generating chunks
Best for: High-fidelity simulations, visualizations, tactical planning
β Option 2: Define TrackSegments as Timeline Events (Like TrackSurfaceState)
public class TrackSegmentTimeSlot : IEntity
{
public Guid Id { get; set; }
public double StartTime { get; set; }
public double EndTime { get; set; }
[Relationship(RelationshipType.Has)]
public TrackSegment Segment { get; set; }
}
Attach to RaceSimulation:
[Relationship(RelationshipType.Owns)]
public ICollection<TrackSegmentTimeSlot> TrackSegments { get; set; } = [];
Pros:
- Fewer references (central mapping)
- Easily reused across all drivers
- Chunks can βlook upβ which segment applies based on ElapsedTime
Cons:
- Requires chunk logic to query central list
- Segments must be time-aligned, not distance-aligned
Best for: Time-driven models where chunk-time aligns with track evolution
β
Option 3: TrackSegments Assigned to Sectors (Fixed Segmentation)
Each Sector in a Lap maps to one or more TrackSegments.
[Relationship(RelationshipType.Owns)]
public ICollection<TrackSegment> Segments { get; set; } = [];
Then, each LapChunk is linked back to its parent Sector, and Sector tells you the segment.
Pros:
- Clean structure
- Fits existing Lap/Sector design
- Decent resolution if sectors are short
Cons:
- Less precise than per-chunk
- Not useful if overtaking changes inside a sector
Best for: Models that donβt need micro-chunk accuracy
π‘ Recommended: Option 1 + Option 2 Hybrid
- Define segments centrally (as in Option 2)
- Assign them to chunks during chunk generation (as in Option 1)
- That gives each chunk direct reference and keeps the timeline explicit
Would you like to go ahead and model this hybrid?
π¬ Prompt 19:
Or do we need a concept of a “Track Definition”, and attach the TrackSegments to that?
π« ChatGPT:
Yes β you’re absolutely thinking in the right direction. A Track Definition as its own entity makes the model far more reusable, modular, and future-proof.
πΉ Why Introduce a Track Definition?
- Encapsulates all layout-specific data:
- Track name , location , length
- Ordered list of TrackSegments
- DRS zones, pit entry/exit markers, elevation (if needed)
- Allows the same race logic to be reused across different circuits
- Enables simulation strategies per circuit
- Lets you reference TrackSegment by distance , time , or order
β Track (IAggregateRoot)
public class Track : IAggregateRoot
{
[Key]
public Guid Id { get; set; }
[ConcurrencyCheck]
public long Version { get; set; }
public string Name { get; set; }
public double TotalLengthMeters { get; set; }
[Relationship(RelationshipType.Owns)]
public ICollection<TrackSegment> Segments { get; set; } = [];
public override string ToString() => Name;
}
β TrackSegment (Updated)
public class TrackSegment : IEntity
{
public Guid Id { get; set; }
public string Name { get; set; }
public TrackSegmentType SegmentType { get; set; }
public double OvertakeChance { get; set; }
public double LengthMeters { get; set; }
public int Sequence { get; set; } // π to maintain order
}
β How This Integrates With Simulation:
- RaceSimulation holds a reference to the chosen
Track - During chunk generation , each chunk is tagged with the correct
TrackSegment(based on distance or time)
[Relationship(RelationshipType.Has)]
public Track Track { get; set; } // in RaceSimulation
- Overtake calculators, tyre wear, spin logic, etc. all query the segment for their probabilities
β Bonus: Can Preload Famous Tracks (Monza, Monaco, Spa)
Would you like to go ahead and model this Track aggregate and link it into RaceSimulation?
π¬ Prompt 20:
The Track Definition should also include Sector positions, Speed Trap position, etc
π« ChatGPT:
Perfect β those are essential to modeling a realistic circuit.
Here’s how we can structure the Track Definition to include:
- Track metadata (name, length)
- TrackSegments in order
- Sectors (used for lap timing + logic)
- Speed Traps (where top speeds are measured)
- Future extensibility for DRS zones, marshal posts, elevation changes, etc.
πΉ Final Structure for Track Aggregate
public class Track : IAggregateRoot
{
[Key]
public Guid Id { get; set; }
[ConcurrencyCheck]
public long Version { get; set; }
public string Name { get; set; }
public double TotalLengthMeters { get; set; }
[Relationship(RelationshipType.Owns)]
public ICollection<TrackSegment> Segments { get; set; } = [];
[Relationship(RelationshipType.Owns)]
public ICollection<TrackSector> Sectors { get; set; } = [];
[Relationship(RelationshipType.Owns)]
public ICollection<SpeedTrap> SpeedTraps { get; set; } = [];
public override string ToString() => Name;
}
πΉ TrackSegment (as above)
Each segment still includes:
- Type (Straight, Bend, Complex)
- Overtake chance
- Length
- Sequence number
πΉ TrackSector (IEntity)
Represents a sector of the track used for lap timing.
public class TrackSector : IEntity
{
public Guid Id { get; set; }
public int SectorNumber { get; set; } // e.g. 1, 2, 3
public double StartDistance { get; set; }
public double EndDistance { get; set; }
public override string ToString() => $"Sector {SectorNumber}";
}
πΉ SpeedTrap (IEntity)
Used to detect top speed performance for analysis or gamification.
public class SpeedTrap : IEntity
{
public Guid Id { get; set; }
public string Name { get; set; }
public double DistanceFromStart { get; set; }
public override string ToString() => Name;
}
β How It All Connects
- LapChunk can infer or be linked to a
TrackSegmentandTrackSector - OvertakeCalculator uses
TrackSegment.OvertakeChance - Simulation/Telemetry can log speed at
SpeedTrap.DistanceFromStart - Sector Times come from summing LapChunk times inside each
TrackSector
Would you like to proceed with modeling this as the Track aggregate and its components?
π¬ Prompt 21:
Which BC should Track Definition go? Does it need a new BC?
π« ChatGPT:
Excellent question β and a thoughtful one.
Letβs explore where the Track Definition best belongs, based on domain boundaries and usage patterns.
πΉ Who Owns the Track Definition?
- Itβs not specific to a single race or driver.
- Itβs reused across simulations, races, scenarios.
- It represents static configuration of a real-world object (a circuit).
β
Best Option: Create a new bounded context: TrackConfiguration
Why:
- Clean separation from simulation logic
- Reflects that Tracks are designed, maintained, and configured independently
- Allows future additions like:
- DRS Zones
- Flag Posts
- Track Layout Changes (historical versions)
- Track Weather Profiles (for realism)
πΉ Bounded Context: TrackConfiguration
Entities:
Track(IAggregateRoot)TrackSegment(IEntity)TrackSector(IEntity)SpeedTrap(IEntity)
Possible future features:
DRSZoneMarshalPostTrackVersionTrackClimateProfile
πΉ How Other BCs Use It
RaceSimulation(fromSimulationBC) has:
[Relationship(RelationshipType.Has)]
public Track Track { get; set; } // Check this for accuracy
OvertakeCalculator,TyreDegCalculator, etc., all queryTrackSegmentviaLapChunkorElapsedTime- UI tools can show track maps and overlays using the
TrackConfigurationdata
Would you like me to prepare this new bounded context and define the aggregate structure next?
π¬ Prompt 22:
Yes. Give a high level view of each BC, and it’s contents. Show it as an ASCII folder structure
π« ChatGPT:
Absolutely β here’s a clean high-level ASCII-style folder structure of your domain, organized into Bounded Contexts with the key entities, aggregates, and components youβve defined so far:
/FresnelModels
β
βββ RaceManagement
β βββ PitStrategyScenario.cs # List of planned pit stops for a driver
β βββ PitStopPlan.cs # Planned pit stop details (lap, reason, tyre)
β
βββ Simulation
β βββ RaceSimulation.cs # Simulation root for a race
β βββ DriverSimulation.cs # Tracks each driver's race simulation
β βββ Lap.cs # One lap of simulated performance
β βββ Sector.cs # One of three lap sectors (timing)
β βββ LapChunk.cs # Time-based segment of a lap (micro-step)
β βββ PitStop.cs # Actual pit stops taken
β βββ TrackSurfaceState.cs # Evolving wet/dry conditions over time
β βββ SimulationSettings.cs # Resolution and enabled calculators
β βββ TimeDelta.cs # Result of calculator for a chunk/lap
β βββ Enums
β βββ TrackCondition.cs
β βββ PitStopReason.cs
β βββ DeltaType.cs
β
βββ DriverPerformance
β βββ Driver.cs # The driver profile (includes tyre wear traits)
β βββ Car.cs # The car and its race-time state (ERS, fuel, DRS)
β
βββ LapTimeCalculation
β βββ Interfaces
β β βββ ITimeDeltaCalculator.cs # Core interface for delta calculators
β βββ LapTimeCalculatorManager.cs # Invokes all calculators in sequence
β βββ LapContext.cs # Snapshot of car/driver/track at current chunk
β βββ Calculators
β β βββ FuelLoadCalculator.cs
β β βββ TyreDegradationCalculator.cs
β β βββ ERSBoostCalculator.cs
β β βββ DRSBoostCalculator.cs
β β βββ DirtyAirCalculator.cs
β β βββ SlipstreamCalculator.cs
β β βββ DriverRecoveryCalculator.cs
β β βββ OvertakeCalculator.cs
β βββ Models
β βββ ISpinProbabilityModel.cs
β βββ IOvertakeProbabilityModel.cs
β
βββ TrackConfiguration
β βββ Track.cs # Aggregate root: defines layout & segments
β βββ TrackSegment.cs # Individual parts of a track (bend, straight)
β βββ TrackSector.cs # Timing sectors (1β3)
β βββ SpeedTrap.cs # Top speed measurement locations
β βββ Enums
β βββ TrackSegmentType.cs
β
This organization aligns with DDD principles and Fresnel conventions:
- Each BC is focused and independent
- Logic-heavy concerns (simulation, calculation) are separated from static data (track config)
- Domain models can evolve cleanly over time
Would you like a visual version next (like a UML diagram), or start generating some code now?
End Of Part 1
After 45-60 mins, we’ve got a reasonably comprehensive structure, with explicit concepts that can be discussed. The model is not fully formed, but we can continue to iterate and evolve it. We’re not generating any code just yet.
In Part 2, we continue extending the model to include Tyre Models, Stints, Race interruptions, and Strategy planning.
And in part 3, we’ll build the code model and create a rapid prototype from it.
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