Modding NHeat - Physics/Final settings

If all the previous values have been carefully set, with a lot of testing, you should now have a car with great physics. Some final values have still to be set, but the difficult part of creating the car's physics has been done already. What's missing ?

TABLE	PARAMETER	DIMENSION
Table Front/Rear	brake_force	min,max
Table Front/Rear	solid_axle	yes/no
Table Front/Rear	removal_impulse
Table Front/Rear	damage_impulse
Table Front/Rear	torque_steer	degree

brakeforce (min,max) range typically will have 0.0 for min value, while max value will be something between 1500 - 3500. It's a matter of testing and what you think to be reasonable brakeforces for your car. Take into consideration what grip you have set your tires to, as low longitudinal grip combined with high brakeforces will eat up the car's tires in very short time.

For testing, you should set brake bias in Garage to something like 60% and check if and when your wheels stop moving. If eventually white smoke shows up each time you slam the brakes, even at high speed, maybe brakeforces are set too high. Check if ONLY front or rear wheels block on braking. On about 60% brake bias and same brakeforce range for front and rear wheels, they should stop at about same time

Obviously here's brakeforce value been a little too high.

solid_axle can be set easily. Unless you edit physics for some really old car, you can put in a no for front wheels and in for most modern cars for rear wheels as well. If you are unsure about your car, try to get info on the net about it's axles.

In Heat you can damage the car's

body
front spoiler
wheels
but unfortunatly only for the wheels you can define how sensitive to damage they are. Body and front spoiler damage sensitivity is hardcoded and cannot be changed.

damage_impulse sets how easy wheels get damaged
removal_impulse sets how easy wheels fly off on damage
Setting either parameter to very high values > 10.0 will make the wheels be almost immune to damage and removal, while very low values < 2.0 will make wheels be kind of touchy - though low values would be more realistic, this can become very annoying. Generally damage_impulse value should be set lower than removal_impulse value

Wanna have servo steering ? Or at least kind of ? torque_steer is the parameter to set the force that's needed on steering. It is defined as degree of flex per 1000 lbs force. Typically it will be set very low or zero for rear wheels, while front wheels' setting would be something close to 1.0

TABLE	PARAMETER	DIMENSION
table EngineNormal	fuel_consumption
table Chassis	fuel_capacity	gallons

fuel_consumption

is some fine-tuning issue that determines how fast you'll empty the gasoline tank, while

fuel_capacity

value sets the tank's volume and adds weight to the car. That weight decreases with fuel draining. Info about what fuel_capacity to be used for a specific car type can be found on the net. It's generally a good idea to make a mind about what relationship tire wear and fuel consumption for the car should have, as this may add some strategical component to races. To figure what fuel_consumption value needs to be set according to what this relationship is intended to be, you'll have to run testlaps again until you run out of fuel.

AI performs badly ?

TABLE	PARAMETER	DIMENSION
Table Chassis	lite_fuel	multiplier
Table Chassis	lite_grip	multiplier
Table Chassis	lite_power	multiplier

Heat treats AI cars pretty different to player cars; it seems to cut off weight from AI cars for example. That makes for better accelerating, but for tipping over in turns as well... The AI cars' setup is defined with track physics and/or GCF files and can be optimized. But there's parameters in physics as well to control the AI drivers' performance

lite_fuel = AI fuel load as multiple to fuel_capacity
lite_grip = AI's tires' grip as multiple to tire grip definitions
lite_power = AI's engine power as multiple to engine's power definitions

It's a little tricky to set these values right; especially setting lite_grip too high may cause the cars to tip over instead of just running faster in turns. A car's turning ability depends on grip/stiffness and it's relationship to power/weight. If the car has very high grip/low stiffness on tires, while being lightweighted and overpowered, it may just topple over at turning in. Some values to start fine tuning with would be

lite_fuel 1.0
lite_grip 1.3
lite_power 1.05

[ Physics: Final Tuning ]