Creating Simple Cars in Second Life

This video shows how to create simple cars in Second Life. I will take you step by step as a car is built. A script will be added to the car. This script is shown below. In this video I show how to set the root prim, create proper wheels and finally, add the script to the car.

Simple Car Script

// Encog's Magic Wagon
// Very simple vehicle script

float forward_power = 15; //Power used to go forward (1 to 30)
float reverse_power = -15; //Power ued to go reverse (-1 to -30)
float turning_ratio = 2.0; //How sharply the vehicle turns. Less is more sharply. (.1 to 10)
string sit_message = "Ride"; //Sit message
string not_owner_message = "You are not the owner of this vehicle ..."; //Not owner message

default
{
    state_entry()
    {
        llSetSitText(sit_message);
        // forward-back,left-right,updown
        llSitTarget(<0.2,0,0.45>, ZERO_ROTATION );
        
        llSetCameraEyeOffset(<-8, 0.0, 5.0>);
        llSetCameraAtOffset(<1.0, 0.0, 2.0>);
        
        llPreloadSound("car_start");
        llPreloadSound("car_run");
        
        //car
        llSetVehicleType(VEHICLE_TYPE_CAR);
        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);
        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);
        llSetVehicleVectorParam(VEHICLE_LINEAR_FRICTION_TIMESCALE, <1000.0, 2.0, 1000.0>);
        llSetVehicleVectorParam(VEHICLE_ANGULAR_FRICTION_TIMESCALE, <10.0, 10.0, 1000.0>);
        llSetVehicleFloatParam(VEHICLE_VERTICAL_ATTRACTION_EFFICIENCY, 0.50);
        llSetVehicleFloatParam(VEHICLE_VERTICAL_ATTRACTION_TIMESCALE, 0.50);
    }
    
    changed(integer change)
    {
        
        
        if (change & CHANGED_LINK)
        {
            
            key agent = llAvatarOnSitTarget();
            if (agent)
            {                
                if (agent != llGetOwner())
                {
                    llSay(0, not_owner_message);
                    llUnSit(agent);
                    llPushObject(agent, <0,0,50>, ZERO_VECTOR, FALSE);
                }
                else
                {
                    llTriggerSound("car_start",1);
                    
                    
                    llMessageLinked(LINK_ALL_CHILDREN , 0, "WHEEL_DRIVING", NULL_KEY);
                    llSleep(.4);
                    llSetStatus(STATUS_PHYSICS, TRUE);
                    llSleep(.1);
                    llRequestPermissions(agent, PERMISSION_TRIGGER_ANIMATION | PERMISSION_TAKE_CONTROLS);

                    llLoopSound("car_run",1);
                }
            }
            else
            {
                llStopSound();
                
                llSetStatus(STATUS_PHYSICS, FALSE);
                llSleep(.4);
                llReleaseControls();
                llTargetOmega(<0,0,0>,PI,0);
                
                llResetScript();
            }
        }
        
    }
    
    run_time_permissions(integer perm)
    {
        if (perm)
        {
            llTakeControls(CONTROL_FWD | CONTROL_BACK | CONTROL_DOWN | CONTROL_UP | CONTROL_RIGHT | 
                            CONTROL_LEFT | CONTROL_ROT_RIGHT | CONTROL_ROT_LEFT, TRUE, FALSE);
        }
    }
    
    control(key id, integer level, integer edge)
    {
        integer reverse=1;
        vector angular_motor;
        
        //get current speed
        vector vel = llGetVel();
        float speed = llVecMag(vel);

        //car controls
        if(level & CONTROL_FWD)
        {
            llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, <forward_power,0,0>);
            reverse=1;
        }
        if(level & CONTROL_BACK)
        {
            llSetVehicleVectorParam(VEHICLE_LINEAR_MOTOR_DIRECTION, <reverse_power,0,0>);
            reverse = -1;
        }

        if(level & (CONTROL_RIGHT|CONTROL_ROT_RIGHT))
        {
            angular_motor.z -= speed / turning_ratio * reverse;
        }
        
        if(level & (CONTROL_LEFT|CONTROL_ROT_LEFT))
        {
            angular_motor.z += speed / turning_ratio * reverse;
        }

        llSetVehicleVectorParam(VEHICLE_ANGULAR_MOTOR_DIRECTION, angular_motor);

    } //end control   
    
    
} //end default