/* * Copyright (c) 2009-2012 jMonkeyEngine * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are * met: * * * Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * * Neither the name of 'jMonkeyEngine' nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ package com.jme3.bullet.joints; import com.jme3.bullet.objects.PhysicsRigidBody; import com.jme3.export.InputCapsule; import com.jme3.export.JmeExporter; import com.jme3.export.JmeImporter; import com.jme3.export.OutputCapsule; import com.jme3.math.Vector3f; import java.io.IOException; import java.util.logging.Level; import java.util.logging.Logger; /** * <i>From bullet manual:</i><br> * Hinge constraint, or revolute joint restricts two additional angular degrees of freedom, * so the body can only rotate around one axis, the hinge axis. * This can be useful to represent doors or wheels rotating around one axis. * The user can specify limits and motor for the hinge. * @author normenhansen */ public class HingeJoint extends PhysicsJoint { protected Vector3f axisA; protected Vector3f axisB; protected boolean angularOnly = false; protected float biasFactor = 0.3f; protected float relaxationFactor = 1.0f; protected float limitSoftness = 0.9f; public HingeJoint() { } /** * Creates a new HingeJoint * @param pivotA local translation of the joint connection point in node A * @param pivotB local translation of the joint connection point in node B */ public HingeJoint(PhysicsRigidBody nodeA, PhysicsRigidBody nodeB, Vector3f pivotA, Vector3f pivotB, Vector3f axisA, Vector3f axisB) { super(nodeA, nodeB, pivotA, pivotB); this.axisA = axisA; this.axisB = axisB; createJoint(); } /** * Enables the motor. * @param enable if true, motor is enabled. * @param targetVelocity the target velocity of the rotation. * @param maxMotorImpulse the max force applied to the hinge to rotate it. */ public void enableMotor(boolean enable, float targetVelocity, float maxMotorImpulse) { enableMotor(objectId, enable, targetVelocity, maxMotorImpulse); } private native void enableMotor(long objectId, boolean enable, float targetVelocity, float maxMotorImpulse); public boolean getEnableMotor() { return getEnableAngularMotor(objectId); } private native boolean getEnableAngularMotor(long objectId); public float getMotorTargetVelocity() { return getMotorTargetVelocity(objectId); } private native float getMotorTargetVelocity(long objectId); public float getMaxMotorImpulse() { return getMaxMotorImpulse(objectId); } private native float getMaxMotorImpulse(long objectId); /** * Sets the limits of this joint. * @param low the low limit in radians. * @param high the high limit in radians. */ public void setLimit(float low, float high) { setLimit(objectId, low, high); } private native void setLimit(long objectId, float low, float high); /** * Sets the limits of this joint. * If you're above the softness, velocities that would shoot through the actual limit are slowed down. The bias be in the range of 0.2 - 0.5. * @param low the low limit in radians. * @param high the high limit in radians. * @param _softness the factor at which the velocity error correction starts operating,i.e a softness of 0.9 means that the vel. corr starts at 90% of the limit range. * @param _biasFactor the magnitude of the position correction. It tells you how strictly the position error (drift ) is corrected. * @param _relaxationFactor the rate at which velocity errors are corrected. This can be seen as the strength of the limits. A low value will make the the limits more spongy. */ public void setLimit(float low, float high, float _softness, float _biasFactor, float _relaxationFactor) { biasFactor = _biasFactor; relaxationFactor = _relaxationFactor; limitSoftness = _softness; setLimit(objectId, low, high, _softness, _biasFactor, _relaxationFactor); } private native void setLimit(long objectId, float low, float high, float _softness, float _biasFactor, float _relaxationFactor); public float getUpperLimit() { return getUpperLimit(objectId); } private native float getUpperLimit(long objectId); public float getLowerLimit() { return getLowerLimit(objectId); } private native float getLowerLimit(long objectId); public void setAngularOnly(boolean angularOnly) { this.angularOnly = angularOnly; setAngularOnly(objectId, angularOnly); } private native void setAngularOnly(long objectId, boolean angularOnly); public float getHingeAngle() { return getHingeAngle(objectId); } private native float getHingeAngle(long objectId); public void write(JmeExporter ex) throws IOException { super.write(ex); OutputCapsule capsule = ex.getCapsule(this); capsule.write(axisA, "axisA", new Vector3f()); capsule.write(axisB, "axisB", new Vector3f()); capsule.write(angularOnly, "angularOnly", false); capsule.write(getLowerLimit(), "lowerLimit", 1e30f); capsule.write(getUpperLimit(), "upperLimit", -1e30f); capsule.write(biasFactor, "biasFactor", 0.3f); capsule.write(relaxationFactor, "relaxationFactor", 1f); capsule.write(limitSoftness, "limitSoftness", 0.9f); capsule.write(getEnableMotor(), "enableAngularMotor", false); capsule.write(getMotorTargetVelocity(), "targetVelocity", 0.0f); capsule.write(getMaxMotorImpulse(), "maxMotorImpulse", 0.0f); } public void read(JmeImporter im) throws IOException { super.read(im); InputCapsule capsule = im.getCapsule(this); this.axisA = (Vector3f) capsule.readSavable("axisA", new Vector3f()); this.axisB = (Vector3f) capsule.readSavable("axisB", new Vector3f()); this.angularOnly = capsule.readBoolean("angularOnly", false); float lowerLimit = capsule.readFloat("lowerLimit", 1e30f); float upperLimit = capsule.readFloat("upperLimit", -1e30f); this.biasFactor = capsule.readFloat("biasFactor", 0.3f); this.relaxationFactor = capsule.readFloat("relaxationFactor", 1f); this.limitSoftness = capsule.readFloat("limitSoftness", 0.9f); boolean enableAngularMotor = capsule.readBoolean("enableAngularMotor", false); float targetVelocity = capsule.readFloat("targetVelocity", 0.0f); float maxMotorImpulse = capsule.readFloat("maxMotorImpulse", 0.0f); createJoint(); enableMotor(enableAngularMotor, targetVelocity, maxMotorImpulse); setLimit(lowerLimit, upperLimit, limitSoftness, biasFactor, relaxationFactor); } protected void createJoint() { objectId = createJoint(nodeA.getObjectId(), nodeB.getObjectId(), pivotA, axisA, pivotB, axisB); Logger.getLogger(this.getClass().getName()).log(Level.FINE, "Created Joint {0}", Long.toHexString(objectId)); } private native long createJoint(long objectIdA, long objectIdB, Vector3f pivotA, Vector3f axisA, Vector3f pivotB, Vector3f axisB); }