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added Erin Catto's 'local' implicit coriolis/gyroscopic force, next to 'Ewert', Cooper, explicit and none

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Configured the gyroscopic demo to show the Dzhanibekov effect
see also https://www.youtube.com/watch?v=L2o9eBl_Gzw
This commit is contained in:
Erwin Coumans
2015-03-24 23:16:45 -07:00
parent 1e13454511
commit 0a04a745dd
4 changed files with 83 additions and 27 deletions
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46
Demos/GyroscopicDemo/GyroscopicSetup.cpp
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@@ -17,43 +17,49 @@ void GyroscopicSetup::initPhysics(GraphicsPhysicsBridge& gfxBridge)
btRigidBody* groundBody;
groundBody = createRigidBody(0, groundTransform, groundShape);
groundBody->setFriction(btSqrt(2));
btVector3 positions[4] = {
btVector3(0.8, -5, 4),
btVector3(0.8, -2, 4),
btVector3(0.8, 2, 4),
btVector3(0.8, 5, 4)
btVector3 positions[5] = {
btVector3( -10, 8,4),
btVector3( -5, 8,4),
btVector3( 0, 8,4),
btVector3( 5, 8,4),
btVector3( 10, 8,4),
};
int gyroflags[4] = {
int gyroflags[5] = {
0,//none, no gyroscopic term
BT_ENABLE_GYROPSCOPIC_FORCE_EXPLICIT,
BT_ENABLE_GYROPSCOPIC_FORCE_IMPLICIT_EWERT,
BT_ENABLE_GYROPSCOPIC_FORCE_IMPLICIT_COOPER,
BT_ENABLE_GYROSCOPIC_FORCE_EXPLICIT,
BT_ENABLE_GYROSCOPIC_FORCE_IMPLICIT_EWERT,
BT_ENABLE_GYROSCOPIC_FORCE_IMPLICIT_COOPER,
BT_ENABLE_GYROSCOPIC_FORCE_IMPLICIT_CATTO,
};
for (int i = 0; i<4; i++)
for (int i = 0; i<5; i++)
{
btCylinderShapeZ* top = new btCylinderShapeZ(btVector3(1, 1, 0.125));
btCapsuleShapeZ* pin = new btCapsuleShapeZ(0.05, 1.5);
top->setMargin(0.01);
btCylinderShapeZ* pin = new btCylinderShapeZ(btVector3(0.1,0.1, 0.2));
btBoxShape* box = new btBoxShape(btVector3(1,0.1,0.1));
box->setMargin(0.01);
pin->setMargin(0.01);
btCompoundShape* compound = new btCompoundShape();
compound->addChildShape(btTransform::getIdentity(), top);
compound->addChildShape(btTransform::getIdentity(), pin);
btTransform offsetBox(btMatrix3x3::getIdentity(),btVector3(0,0,0.2));
compound->addChildShape(offsetBox, box);
btScalar masses[2] = {0.3,0.1};
btVector3 localInertia;
top->calculateLocalInertia(1, localInertia);
btTransform principal;
compound->calculatePrincipalAxisTransform(masses,principal,localInertia);
btRigidBody* body = new btRigidBody(1, 0, compound, localInertia);
btTransform tr;
tr.setIdentity();
tr.setOrigin(positions[i]);
body->setCenterOfMassTransform(tr);
body->setAngularVelocity(btVector3(1, 17, 3));
body->setLinearVelocity(btVector3(0, 0, 0));
body->setAngularVelocity(btVector3(0, 0.1, 10));//51));
//body->setLinearVelocity(btVector3(3, 0, 0));
body->setFriction(btSqrt(1));
m_dynamicsWorld->addRigidBody(body);
body->setFlags(gyroflags[i]);
body->setDamping(0.00001f, 0.0001f);
m_dynamicsWorld->getSolverInfo().m_maxGyroscopicForce = 10.f;
body->setDamping(0.0000f, 0.000f);
}