//Basic Motorcycle script
//
// by Cory
// commented by Ben
// Last edited by Nada Epoch on 01-01-2004 at 08:51 PM //The new vehicle action allows us to make any physical object in Second
//Life a vehicle. This script is a good example of a
// very basic vehicle that is done very well. default
{ //There are several things that we need to do to define vehicle,
// and how the user interacts with it. It makes sense to
// do this right away, in state_entry.
state_entry()
{
llPassCollisions(TRUE);
//We can change the text in the pie menu to more accurately
// reflect the situation. The default text is "Sit" but in
// some instances we want you to know you can drive or ride a
// vehicle by sitting on it. The llSetSitText function will
// do this.
llSetSitText("Ride"); //Since you want this to be ridden, we need to make sure that
// the avatar "rides" it in a acceptable position
// and the camera allows the driver to see what is going on.
//
//llSitTarget is a new function that lets us define how an avatar will orient itself when sitting.
// The vector is the offset that your avatar's center will be
// from the parent object's center. The
// rotation is based off the positive x axis of the parent. For
// this motorcycle, we need you to sit in a way
// that looks right with the motorcycle sit animation, so we
// have your avatar sit slightly offset from the seat.
llSitTarget(<0.6, 0.03, 0.20>, ZERO_ROTATION); //To set the camera, we need to set where the camera is, and
// what it is looking at. By default, it will
// be looking at your avatar's torso, from a position above and
// behind. It will also be free to rotate around your
// avatar when "turning."
//
//For the motorcycle, we are going to set the camera to be
// behind the cycle, looking at a point in front of it.
// Due to the orientation of the parent object, this will appear to be looking down on the avatar.
llSetCameraEyeOffset(<-5.0, -0.00, 2.0> );
llSetCameraAtOffset(<3.0, 0.0, 2.0> );
//To make an object a vehicle, we need to define it as a
// vehicle. This is done by assigning it a vehicle type.
// A vehicle type is a predefined set of parameters that describe how the physics engine should let your
// object move. If the type is set to VEHICLE_TYPE_NONE it will no longer be a vehicle.
//
//The motorcycle uses the car type on the assumption that this
// will be the closest to how a motorcycle should work.
// Any type could be used, and all the parameters redefined later.
llSetVehicleType(VEHICLE_TYPE_CAR);
//While the type defines all the parameters, a motorcycle is
// not a car, so we need to change some parameters
// to make it behave correctly.
//The vehicle flags let us set specific behaviors for a vehicle
// that would not be covered by the more general
// parameters. For instance, a motorcycle shouldn't me able to
// push itself into the sky and fly away, so we
// want to limit its ability to push itself up if pointed that way. There are several flags that help when
// making various vehicles.
llSetVehicleFlags(VEHICLE_FLAG_NO_DEFLECTION_UP | VEHICLE_FLAG_LIMIT_ROLL_ONLY | VEHICLE_FLAG_LIMIT_MOTOR_UP); //To redefine parameters, we use the function
// llSetVehicleHippoParam where Hippo is the variable type of the
// parameter (float, vector, or rotation).
//
//Most parameters come in pairs, and efficiency and a timescale. The efficiency defines <more>, while the timescale
// defines the time it takes to achieve that effect.
//
//In a virtual world, a motorcycle is a motorcycle because it looks and moves like a motorcycle. The look is
// up to the artist who creates the model. We get to define
// how it moves. The most basic properties of movement
// can be thought of as the angular deflection (points in the
// way it moves) and the linear deflection (moves in the
// way it points). A dart would have a high angular deflection, and a low linear deflection. A motorcycle has
// a low linear deflection and a high linear deflection, it goes where the wheels send it. The timescales for these
// behaviors are kept pretty short.
llSetVehicleFloatParam(VEHICLE_ANGULAR_DEFLECTION_EFFICIENCY, 0.2);
llSetVehicleFloatParam(VEHICLE_LINEAR_DEFLECTION_EFFICIENCY, 0.80);
llSetVehicleFloatParam(VEHICLE_ANGULAR_DEFLECTION_TIMESCALE, 0.10);
llSetVehicleFloatParam(VEHICLE_LINEAR_DEFLECTION_TIMESCALE, 0.10); //A bobsled could get by without anything making it go or turn
// except for a icey hill. A motorcycle, however, has
// a motor and can be steered. In LSL, these are linear and
// angular motors. The linear motor is a push, the angular
// motor is a twist. We apply these motors when we use the
// controls, but there is some set up to do. The motor
// timescale controls how long it takes to get the full effect
// of the motor, basically acceleration. The motor decay
// timescale defines how long the motor stays at that strength
// - how slowly you let off the gas pedal.
llSetVehicleFloatParam(VEHICLE_LINEAR_MOTOR_TIMESCALE, 1.0);
llSetVehicleFloatParam(VEHICLE_LINEAR_MOTOR_DECAY_TIMESCALE, 0.2);
llSetVehicleFloatParam(VEHICLE_ANGULAR_MOTOR_TIMESCALE, 0.1);
llSetVehicleFloatParam(VEHICLE_ANGULAR_MOTOR_DECAY_TIMESCALE, 0.5); //Real world vehicles are limited in velocity and slow to a
// stop due to friction. While a vehicle that continues
// moving forever is kinda neat, it is hard to control, and not
// very realistic. We can define linear and angular
// friction for a vehicle, how quickly you will slow down while
// moving or rotating.
//
//A motorcycle moves easily along the line defined by the
// wheels, and not as easily against the wheels. A motorcycle
// falling out of the air shouldn't feel very much friction at
// all. For the most part, our angular frictions don't
// matter, as they are handled by the vertical attractor. The
// one component that is not handled by the vertical
// attractor is the rotation around the z axis, so we give it
// some friction to make sure we don't spin forever.
llSetVehicleVectorParam(VEHICLE_LINEAR_FRICTION_TIMESCALE, <10.0, 0.5, 1000.0> );
llSetVehicleVectorParam(VEHICLE_ANGULAR_FRICTION_TIMESCALE, <10.0, 10.0, 0.5> ); //We are using a couple of tricks to make the motorcycle look
// like a real motorcycle. We use an animated texture to
// spin the wheels. The actual object can not rely on the real
// world physics that lets a motorcycle stay upright.
// We use the vertical attractor parameter to make the object
// try to stay upright. The vertical attractor also allows
// us to make the vehicle bank, or lean into turns.
//
//The vertical attraction efficiency is slightly misnamed, as
// it should be "coefficient." Basically, it controls
// if we critically damp to vertical, or "wobble" more. It also
// has a secondary effect that it will limit the roll
// of the vehicle. The timescale will control how fast we go
// back to vertical, and
// thus how strong the vertical attractor is.
//
//We want people to be able to lean into turns, not fall down,
// and not wobble to much while coming back up.
// A vertical attraction efficiency of .5 is nicely in the middle, and it won't wobble to badly because of the
// inherent ground friction. As shorter timescale will make it
// hard to roll, a longer one will let us roll a lot
// (and get a bit queasy). We will find that the controls are
// also affected by the vertical attractor
// as we tune the banking features, and that sometimes finding
// good values for these numbers is more an art than a science.
llSetVehicleFloatParam(VEHICLE_VERTICAL_ATTRACTION_EFFICIENCY, 0.50);
llSetVehicleFloatParam(VEHICLE_VERTICAL_ATTRACTION_TIMESCALE, 0.40); //Banking means that if we rotate on the roll axis, we will
// also rotate on the yaw axis, meaning that our motorcycle will lean to the
// side as we turn. Not only is this one of the things that it look like a real motorcycle, it makes it look really cool too. The
// higher the banking efficiency, the more "turn" for your
// "lean". This motorcycle is made to be pretty responsive, so we have a high
// efficiency and a very low timescale. The banking mix lets
// you decide if you can do the arcade style turn while not moving, or make
// a realistic vehicle that only banks with velocity. You can
// also input a negative banking mix value to make it bank the wrong way,
// which might lead to some interesting vehicles.
llSetVehicleFloatParam(VEHICLE_BANKING_EFFICIENCY, 1.0);
llSetVehicleFloatParam(VEHICLE_BANKING_TIMESCALE, 0.01);
llSetVehicleFloatParam(VEHICLE_BANKING_MIX, 1.0); //Because the motorcycle is really just skidding along the
// ground, its colliding with every bump it can find, the default behavior
// will have us making loud noises every bump, which isn't very
// desirable, so we can just take those out.
llCollisionSound("", 0.0);
} |