public TreadSegment(Vector3 segmentPosition, Entity body, TreadSegmentDescription treadSegmentDescription)
{
Entity = new Cylinder(segmentPosition, treadSegmentDescription.Width, treadSegmentDescription.Radius, treadSegmentDescription.Mass);
Entity.Material.KineticFriction = treadSegmentDescription.Friction;
Entity.Material.StaticFriction = treadSegmentDescription.Friction;
Entity.Orientation = Quaternion.CreateFromAxisAngle(Vector3.Forward, MathHelper.PiOver2);
//Preventing the occasional pointless collision pair can speed things up.
CollisionRules.AddRule(Entity, body, CollisionRule.NoBroadPhase);
//Connect the wheel to the body.
SuspensionAxisJoint = new PointOnLineJoint(body, Entity, Entity.Position, Vector3.Down, Entity.Position);
SuspensionLengthLimit = new LinearAxisLimit(body, Entity, Entity.Position, Entity.Position, Vector3.Down, -treadSegmentDescription.SuspensionLength, 0);
//This linear axis motor will give the suspension its springiness by pushing the wheels outward.
SuspensionSpring = new LinearAxisMotor(body, Entity, Entity.Position, Entity.Position, Vector3.Down);
SuspensionSpring.Settings.Mode = MotorMode.Servomechanism;
SuspensionSpring.Settings.Servo.Goal = 0;
SuspensionSpring.Settings.Servo.SpringSettings.Stiffness = treadSegmentDescription.SuspensionStiffness;
SuspensionSpring.Settings.Servo.SpringSettings.Damping = treadSegmentDescription.SuspensionDamping;
SuspensionAngularJoint = new RevoluteAngularJoint(body, Entity, Vector3.Right);
//Make the joint extremely rigid. There are going to be extreme conditions when the wheels get up to speed;
//we don't want the forces involved to torque the wheel off the frame!
SuspensionAngularJoint.SpringSettings.Damping *= Entity.Mass * 50;
SuspensionAngularJoint.SpringSettings.Stiffness *= Entity.Mass * 50;
//Motorize the wheel.
Motor = new RevoluteMotor(body, Entity, Vector3.Left);
Motor.Settings.VelocityMotor.Softness = treadSegmentDescription.MotorSoftness;
Motor.Settings.MaximumForce = treadSegmentDescription.MotorMaximumForce;
}
public Tank(Vector3 position)
{
Body = new Box(position, 4, (Fix64).5m, 5, 20);
Body.CollisionInformation.LocalPosition = new Vector3(0, (Fix64).8m, 0);
var treadDescription = new TreadSegmentDescription
{
Width = (Fix64)0.5m,
Radius = (Fix64)0.5m,
Mass = 1,
Friction = (Fix64)2f,
MotorSoftness = 0,//0.3m,
MotorMaximumForce = 30,
SuspensionDamping = 70,
SuspensionStiffness = 300,
SuspensionLength = 1
};
RightTread = new Tread(Body, new Vector3((Fix64)(-1.8m), (Fix64)(-.2m), (Fix64)(-2.1m)), 5, 1, treadDescription);
LeftTread = new Tread(Body, new Vector3((Fix64)1.8m, (Fix64)(-.2m), (Fix64)(-2.1m)), 5, 1, treadDescription);
Turret = new Turret(Body, new Vector3(0, (Fix64)1.5m, (Fix64)0.5m));
}
public Tank(Vector3 position)
{
Body = new Box(position, 4, .5f, 5, 20);
Body.CollisionInformation.LocalPosition = new Vector3(0, .8f, 0);
var treadDescription = new TreadSegmentDescription
{
Width = 0.5f,
Radius = 0.5f,
Mass = 1,
Friction = 2f,
MotorSoftness = 0,//0.3f,
MotorMaximumForce = 30,
SuspensionDamping = 70,
SuspensionStiffness = 300,
SuspensionLength = 1
};
RightTread = new Tread(Body, new Vector3(-1.8f, -.2f, -2.1f), 5, 1, treadDescription);
LeftTread = new Tread(Body, new Vector3(1.8f, -.2f, -2.1f), 5, 1, treadDescription);
Turret = new Turret(Body, new Vector3(0, 1.5f, 0.5f));
}
public Tank(Vector3 position)
{
Body = new Box(position, 4, .5f, 5, 20);
Body.CollisionInformation.LocalPosition = new Vector3(0, .8f, 0);
var treadDescription = new TreadSegmentDescription
{
Width = 0.5f,
Radius = 0.5f,
Mass = 1,
Friction = 2f,
MotorSoftness = 0,//0.3f,
MotorMaximumForce = 30,
SuspensionDamping = 70,
SuspensionStiffness = 300,
SuspensionLength = 1
};
RightTread = new Tread(Body, new Vector3(-1.8f, -.2f, -2.1f), 5, 1, treadDescription);
LeftTread = new Tread(Body, new Vector3(1.8f, -.2f, -2.1f), 5, 1, treadDescription);
Turret = new Turret(Body, new Vector3(0, 1.5f, 0.5f));
}
public Tread(Entity tankBody, Vector3 offsetToFrontOfTread, int segmentCount, Fix64 spacing, TreadSegmentDescription treadSegmentDescription)
{
Segments = new List <TreadSegment>();
Vector3 nextSegmentPosition = tankBody.Position + offsetToFrontOfTread;
//The front of the tread includes the radius of the first segment.
nextSegmentPosition.Z += treadSegmentDescription.Radius * (Fix64)0.5m;
for (int i = 0; i < segmentCount; ++i)
{
Segments.Add(new TreadSegment(nextSegmentPosition, tankBody, treadSegmentDescription));
//The tread offset starts at the front of the vehicle and moves backward.
nextSegmentPosition.Z += spacing;
}
//Don't let the tread segments rotate relative to each other.
SegmentAngularBindings = new List <NoRotationJoint>();
for (int i = 1; i < segmentCount; ++i)
{
//Create constraints linking the segments together to ensure that the power of one motor is felt by other segments.
SegmentAngularBindings.Add(new NoRotationJoint(Segments[i - 1].Entity, Segments[i].Entity));
//Don't let the tread segments collide.
CollisionRules.AddRule(Segments[i - 1].Entity, Segments[i].Entity, CollisionRule.NoBroadPhase);
}
//Note: You can organize this in different ways. For example, you could have one motor which drives one wheel, which
//in turn drives other wheels through these NoRotationJoints.
//In such a one-motor model, it may be a good idea for stability to bind all wheels directly to the drive wheel with
//NoRotationJoints rather than using a chain of one wheel to the next.
//Per-wheel drive motors are used in this example just because it is slightly more intuitive at a glance.
//Each segment is no different than the others.
}
public TreadSegment(Vector3 segmentPosition, Entity body, TreadSegmentDescription treadSegmentDescription)
{
Entity = new Cylinder(segmentPosition, treadSegmentDescription.Width, treadSegmentDescription.Radius, treadSegmentDescription.Mass);
Entity.Material.KineticFriction = treadSegmentDescription.Friction;
Entity.Material.StaticFriction = treadSegmentDescription.Friction;
Entity.Orientation = Quaternion.CreateFromAxisAngle(Vector3.Forward, MathHelper.PiOver2);
//Preventing the occasional pointless collision pair can speed things up.
CollisionRules.AddRule(Entity, body, CollisionRule.NoBroadPhase);
//Connect the wheel to the body.
SuspensionAxisJoint = new PointOnLineJoint(body, Entity, Entity.Position, Vector3.Down, Entity.Position);
SuspensionLengthLimit = new LinearAxisLimit(body, Entity, Entity.Position, Entity.Position, Vector3.Down, -treadSegmentDescription.SuspensionLength, 0);
//This linear axis motor will give the suspension its springiness by pushing the wheels outward.
SuspensionSpring = new LinearAxisMotor(body, Entity, Entity.Position, Entity.Position, Vector3.Down);
SuspensionSpring.Settings.Mode = MotorMode.Servomechanism;
SuspensionSpring.Settings.Servo.Goal = 0;
SuspensionSpring.Settings.Servo.SpringSettings.Stiffness = treadSegmentDescription.SuspensionStiffness;
SuspensionSpring.Settings.Servo.SpringSettings.Damping = treadSegmentDescription.SuspensionDamping;
SuspensionAngularJoint = new RevoluteAngularJoint(body, Entity, Vector3.Right);
//Make the joint extremely rigid. There are going to be extreme conditions when the wheels get up to speed;
//we don't want the forces involved to torque the wheel off the frame!
SuspensionAngularJoint.SpringSettings.Damping *= Entity.Mass * 50;
SuspensionAngularJoint.SpringSettings.Stiffness *= Entity.Mass * 50;
//Motorize the wheel.
Motor = new RevoluteMotor(body, Entity, Vector3.Left);
Motor.Settings.VelocityMotor.Softness = treadSegmentDescription.MotorSoftness;
Motor.Settings.MaximumForce = treadSegmentDescription.MotorMaximumForce;
}
public Tread(Entity tankBody, Vector3 offsetToFrontOfTread, int segmentCount, float spacing, TreadSegmentDescription treadSegmentDescription)
{
Segments = new List<TreadSegment>();
Vector3 nextSegmentPosition = tankBody.Position + offsetToFrontOfTread;
//The front of the tread includes the radius of the first segment.
nextSegmentPosition.Z += treadSegmentDescription.Radius * 0.5f;
for (int i = 0; i < segmentCount; ++i)
{
Segments.Add(new TreadSegment(nextSegmentPosition, tankBody, treadSegmentDescription));
//The tread offset starts at the front of the vehicle and moves backward.
nextSegmentPosition.Z += spacing;
}
//Don't let the tread segments rotate relative to each other.
SegmentAngularBindings = new List<NoRotationJoint>();
for (int i = 1; i < segmentCount; ++i)
{
//Create constraints linking the segments together to ensure that the power of one motor is felt by other segments.
SegmentAngularBindings.Add(new NoRotationJoint(Segments[i - 1].Entity, Segments[i].Entity));
//Don't let the tread segments collide.
CollisionRules.AddRule(Segments[i - 1].Entity, Segments[i].Entity, CollisionRule.NoBroadPhase);
}
//Note: You can organize this in different ways. For example, you could have one motor which drives one wheel, which
//in turn drives other wheels through these NoRotationJoints.
//In such a one-motor model, it may be a good idea for stability to bind all wheels directly to the drive wheel with
//NoRotationJoints rather than using a chain of one wheel to the next.
//Per-wheel drive motors are used in this example just because it is slightly more intuitive at a glance.
//Each segment is no different than the others.
}
