ilikecats/stk-code_catmod
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Keep flying karts parallel to the ground in the physics, not outside.

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This avoids odd side effects that happened before (e.g. very bad collisions
with track; problems when dropping karts on rescue on the walldriving branch).
This commit is contained in:
hiker 2014-08-05 08:21:52 +10:00
parent 7e65d4d346
commit 44da1fb4f2
2 changed files with 12 additions and 25 deletions
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26
src/karts/kart.cpp
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@ -1098,7 +1098,7 @@ void Kart::update(float dt)
// TODO: hiker said this probably will be moved to btKart or so when updating bullet engine.
// Neutralize any yaw change if the kart leaves the ground, so the kart falls more or less
// straight after jumping, but still allowing some "boat shake" (roll and pitch).
// straight after jumping, but still allowing some "boat shake" (roIll and pitch).
// Otherwise many non perfect jumps end in a total roll over or a serious change of
// direction, sometimes 90 or even full U turn (real but less fun for a karting game).
// As side effect steering becames a bit less responsive (any wheel on air), but not too bad.
@ -2023,30 +2023,6 @@ void Kart::updatePhysics(float dt)
m_max_speed->setMinSpeed(min_speed);
m_max_speed->update(dt);
// If the kart is flying, keep its up-axis aligned to gravity (which in
// turn typically means the kart is parallel to the ground). This avoids
// that the kart rotates in mid-air and lands on its side.
if(m_vehicle->getNumWheelsOnGround()==0)
{
btVector3 kart_up = getTrans().getBasis().getColumn(1); // up vector
btVector3 terrain_up = m_body->getGravity();
float g = World::getWorld()->getTrack()->getGravity();
// Normalize the gravity, g is the length of the vector
btVector3 new_up = 0.9f * kart_up + 0.1f * terrain_up/-g;
// Get the rotation (hpr) based on current heading.
Vec3 rotation(getHeading(), new_up);
btMatrix3x3 m;
m.setEulerZYX(rotation.getX(), rotation.getY(), rotation.getZ());
// We can't use getXYZ() for the position here, since the position is
// based on interpolation, while the actual center-of-mass-transform
// is based on the actual value every 1/60 of a second (using getXYZ()
// would result in the kart being pushed ahead a bit, making it jump
// much further, depending on fps)
btTransform new_trans(m, m_body->getCenterOfMassTransform().getOrigin());
//setTrans(new_trans);
m_body->setCenterOfMassTransform(new_trans);
}
// To avoid tunneling (which can happen on long falls), clamp the
// velocity in Y direction. Tunneling can happen if the Y velocity
// is larger than the maximum suspension travel (per frame), since then

11
src/physics/btKart.cpp
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@ -387,6 +387,17 @@ void btKart::updateVehicle( btScalar step )
if(m_wheelInfo[i].m_raycastInfo.m_isInContact)
m_num_wheels_on_ground++;
}
// If the kart is flying, try to keep it parallel to the ground.
if(m_num_wheels_on_ground==0)
{
btVector3 kart_up = getChassisWorldTransform().getBasis().getColumn(1);
btVector3 terrain_up(0,1,0);
btVector3 axis = kart_up.cross(terrain_up);
// Times 10 gives a nicely balanced feeling.
m_chassisBody->applyTorqueImpulse(axis * 10);
}
// Work around: make sure that either both wheels on one axis
// are on ground, or none of them. This avoids the problem of
// the kart suddenly getting additional angular velocity because