Exemplo n.º 1
0
void CharacterController::applyMotor(int index, btScalar dt, btVector3& worldVelocity, std::vector<btVector3>& velocities, std::vector<btScalar>& weights) {
    assert(index < (int)(_motors.size()));
    CharacterController::CharacterMotor& motor = _motors[index];
    if (motor.hTimescale >= MAX_CHARACTER_MOTOR_TIMESCALE && motor.vTimescale >= MAX_CHARACTER_MOTOR_TIMESCALE) {
        // nothing to do
        return;
    }

    // rotate into motor-frame
    btVector3 axis = motor.rotation.getAxis();
    btScalar angle = motor.rotation.getAngle();
    btVector3 velocity = worldVelocity.rotate(axis, -angle);

    if (_state == State::Hover || motor.hTimescale == motor.vTimescale) {
        // modify velocity
        btScalar tau = dt / motor.hTimescale;
        if (tau > 1.0f) {
            tau = 1.0f;
        }
        velocity += (motor.velocity - velocity) * tau;

        // rotate back into world-frame
        velocity = velocity.rotate(axis, angle);

        // store the velocity and weight
        velocities.push_back(velocity);
        weights.push_back(tau);
    } else {
        // compute local UP
        btVector3 up = _currentUp.rotate(axis, -angle);

        // split velocity into horizontal and vertical components
        btVector3 vVelocity = velocity.dot(up) * up;
        btVector3 hVelocity = velocity - vVelocity;
        btVector3 vTargetVelocity = motor.velocity.dot(up) * up;
        btVector3 hTargetVelocity = motor.velocity - vTargetVelocity;

        // modify each component separately
        btScalar maxTau = 0.0f;
        if (motor.hTimescale < MAX_CHARACTER_MOTOR_TIMESCALE) {
            btScalar tau = dt / motor.hTimescale;
            if (tau > 1.0f) {
                tau = 1.0f;
            }
            maxTau = tau;
            hVelocity += (hTargetVelocity - hVelocity) * tau;
        }
        if (motor.vTimescale < MAX_CHARACTER_MOTOR_TIMESCALE) {
            btScalar tau = dt / motor.vTimescale;
            if (tau > 1.0f) {
                tau = 1.0f;
            }
            if (tau > maxTau) {
                maxTau = tau;
            }
            vVelocity += (vTargetVelocity - vVelocity) * tau;
        }

        // add components back together and rotate into world-frame
        velocity = (hVelocity + vVelocity).rotate(axis, angle);

        // store velocity and weights
        velocities.push_back(velocity);
        weights.push_back(maxTau);
    }
}