Class Frame

  • Direct Known Subclasses:
    FixedFrame, Joint, MovableFrame

    public class Frame
    extends StateData
    The type of node of forward kinematic trees.

    Types of joints are implemented as subclasses of Frame. The
    responsibility of a joint is to implement the getTransform() method that
    returns the transform of the frame relative to whatever parent it is
    attached to.

    The getTransform() method takes as parameter the set of joint values
    State for the tree. Joint values for a particular frame can be accessed
    via State::getQ(). A frame may contain pointers to other frames so that
    the transform of a frame may depend on the joint values for other frames
    also.
    • Constructor Detail

      • Frame

        public Frame​(long cPtr,
                     boolean cMemoryOwn)
    • Method Detail

      • getCPtr

        public static long getCPtr​(Frame obj)
      • multiplyTransform

        public void multiplyTransform​(Transform3D parent,
                                      State state,
                                      Transform3D result)
        Post-multiply the transform of the frame to the parent transform.

        The transform is calculated for the joint values of state.

        The exact implementation of getTransform() depends on the type of
        frame. See for example RevoluteJoint and PrismaticJoint.

        Parameters:
        parent - [in] The world transform of the parent frame.
        state - [in] Joint values for the forward kinematics tree.
        result - [in] The transform of the frame in the world frame.
      • getTransform

        public Transform3D getTransform​(State state)
        The transform of the frame relative to its parent.

        The transform is calculated for the joint values of state.

        The exact implementation of getTransform() depends on the type of
        frame. See for example RevoluteJoint and PrismaticJoint.

        Parameters:
        state - [in] Joint values for the forward kinematics tree.

        Returns:
        The transform of the frame relative to its parent.
      • getDOF

        public int getDOF()
        The number of degrees of freedom (dof) of the frame.

        The dof is the number of joint values that are used for controlling
        the frame.

        Given a set joint values of type State, the getDof() number of joint
        values for the frame can be read and written with State::getQ() and
        State::setQ().

        Returns:
        The number of degrees of freedom of the frame.
      • getParent

        public Frame getParent()
        The parent of the frame or NULL if the frame is a DAF.
      • getParent

        public Frame getParent​(State state)
        Returns the parent of the frame

        If no static parent exists it look for at DAF parent. If such
        does not exists either it returns NULL.

        Parameters:
        state - [in] the state to consider
        Returns:
        the parent
      • getDafParent

        public Frame getDafParent​(State state)
      • getChildrenList

        public VectorFramePtr getChildrenList​(State state)
        get a list of all frame children
        Parameters:
        state - [in] the state of to look for children in.
        Returns:
        a vector with the children
      • attachTo

        public void attachTo​(FramePtr parent,
                             State state)
        Move a frame within the tree.

        The frame frame is detached from its parent and reattached to
        parent. The frames frame and parent must both belong to the
        same kinematics tree.

        Only frames with no static parent (see getParent()) can be moved.

        Parameters:
        parent - [in] The frame to attach frame to.
        state - [inout] The state to which the attachment is written.
      • isDAF

        public boolean isDAF()
        Test if this frame is a Dynamically Attachable Frame
        Returns:
        true if this frame is a DAF, false otherwise
      • wTf

        public Transform3D wTf​(State state)
        Get the transform relative to world.
        Parameters:
        state - [in] the state.
        Returns:
        transform relative to world.
      • fTf

        public Transform3D fTf​(FrameCPtr to,
                               State state)
        Get the transform of other frame relative to this frame.
        Parameters:
        to - [in] the other frame
        state - [in] the state.
        Returns:
        transform of frame to relative to this frame.
      • equals

        public boolean equals​(Frame rhs)
        Compares the Frame to see if they are the same
        Checks the statedata, parent frame and chld frame
        Parameters:
        rhs - [in] the Frame to compare with
        Returns:
        true if equal
      • notEqual

        public boolean notEqual​(Frame rhs)
        Check if not equal
        Parameters:
        rhs - [in] the Frame to compare with
        Returns:
        true if not equal
      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object