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changed force coordinate frame

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This commit is contained in:
Dave Schuyler 2003-07-25 22:06:40 +00:00
parent ad4be177e2
commit e88c6726d7
1 changed files with 41 additions and 18 deletions
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59
panda/src/physics/physicsCollisionHandler.cxx
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@ -59,37 +59,60 @@ apply_linear_force(ColliderDef &def, const LVector3f &force) {
return;
}
ActorNode *actor=DCAST(ActorNode, def._node);
float friction=0.9f;
LVector3f vel=actor->get_physics_object()->get_velocity();
physics_debug("apply_linear_force() {");
physics_debug(" vel "<<vel<<" len "<<vel.length());
physics_debug(" force "<<force<<" len "<<force.length());
LVector3f old_vel=vel;
LVector3f adjustment=force;
// Copy the force vector while translating it
// into the physics object coordinate system:
LVector3f adjustment=force*actor->get_physics_object()->get_lcs();
physics_debug(" adjustment set "<<adjustment<<" len "<<adjustment.length());
adjustment.normalize();
adjustment*=adjustment.dot(vel);
physics_debug(" adjustment "<<adjustment<<" len "<<adjustment.length());
float angle=adjustment.dot(vel);
vel-=adjustment;
physics_debug(" vel "<<vel<<" len "<<vel.length());
physics_debug(" angle "<<angle);
if (angle<=0.0f) {
// ...avoid amplifying the velocity by checking to see
// that the adjustment and the velocity are more than
// right-angles (i.e. obtuse angle).
float almostStationary=0.1f;
if (vel.length()>almostStationary) {
physics_debug(" vel > almostStationary");
friction*=0.01f;
physics_debug(" adjustment nrm "<<adjustment<<" len "<<adjustment.length());
float adjustmentLength=-(adjustment.dot(vel));
physics_debug(" adjustmentLength "<<adjustmentLength);
// Are we in contact with something:
if (adjustmentLength>0.0f) {
physics_debug(" positive contact");
adjustment*=adjustmentLength;
physics_debug(" adjustment mul "<<adjustment<<" len "<<adjustment.length());
// This adjustment to our velocity will not reflect us off the surface,
// but will deflect us parallel (or tangent) to the surface:
vel+=adjustment;
physics_debug(" vel "<<vel<<" len "<<vel.length());
physics_debug(" angle "<<adjustmentLength);
const float almostStationary=0.1f;
float friction=0.9f;
// This velocity is not very accurate, but it's better than using
// the pre-collision-tested velocity for now. This may need to be
// better:
LVector3f implicitVel=actor->get_physics_object()->get_implicit_velocity();
physics_debug(" implicitVel "<<implicitVel<<" len "<<implicitVel.length());
// Determine the friction:
if (implicitVel.length()<almostStationary) {
physics_debug(" static friction");
friction=0.9f;
} else {
physics_debug(" dynamic friction");
friction=0.1f;
}
//vel*=1.0f-friction;
// Apply the friction:
vel*=1.0f-friction;
} else if (adjustmentLength==0.0f) {
physics_debug(" brushing contact");
} else {
physics_debug(" negative contact");
}
#ifndef NDEBUG //[
if (vel.length() > old_vel.length()) {
// This is a check to avoid adding engergy:
physics_debug(" vel.length() > old_vel.length() "<<vel.length()<<" > "<<old_vel.length());
}
if (vel.length() > 10.0f) {
// This is a check to see if the velocity is higher than I expect it
// to go. The check value is arbitrary.
physics_debug(" vel.length() > 10.0f "<<vel.length());
}
#endif //]
@ -97,6 +120,6 @@ apply_linear_force(ColliderDef &def, const LVector3f &force) {
physics_debug(" force "<<force<<" len "<<force.length());
physics_debug(" vel "<<vel<<" len "<<vel.length());
physics_debug("}");
actor->set_contact_vector(force);
actor->set_contact_vector(adjustment);
actor->get_physics_object()->set_velocity(vel);
}