viewinfo.html

JAVA多媒体开发类库说明

<A NAME="getCoexistenceToImagePlate(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D, javax.media.j3d.Transform3D)"><!-- --></A><H3>
getCoexistenceToImagePlate</H3>
<PRE>
public void <B>getCoexistenceToImagePlate</B>(<A HREF="../../../../../javax/media/j3d/Canvas3D.html" title="class in javax.media.j3d">Canvas3D</A>&nbsp;c3d,
                                       <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;coe2ipl,
                                       <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;coe2ipr)</PRE>
<DL>
<DD>Gets the current transforms from coexistence coordinates to image plate
 coordinates and copies them into the given Transform3Ds.  The default
 coexistence centering enable and window movement policies are
 <code>true</code> and <code>PHYSICAL_WORLD</code> respectively, which
 will center coexistence coordinates to the middle of the canvas,
 aligned with the screen (image plate). A movement policy of
 <code>VIRTUAL_WORLD</code> centers coexistence coordinates to the
 middle of the screen.<p>

 If coexistence centering is turned off, then canvases and screens can
 have arbitrary positions with respect to coexistence, set through the
 the Screen3D <code>trackerBaseToImagePlate</code> transform and the
 PhysicalEnvironment <code>coexistenceToTrackerBase</code> transform.
 These are calibration constants used for multiple fixed screen displays.
 For head mounted displays the transform is determined by the user head
 position along with calibration parameters found in Screen3D and
 PhysicalBody. (See the source code for the private method
 <code>getEyesHMD</code> for more information).<p>

 With a monoscopic canvas the image plate transform is copied to the
 first argument and the second argument is not used.  For a stereo
 canvas the first argument receives the left image plate transform, and
 if the second argument is non-null it receives the right image plate
 transform.  These transforms are always the same unless a head mounted
 display driven by a single stereo canvas is in use.<p>
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>c3d</CODE> - the Canvas3D associated with the image plate<DD><CODE>coe2ipl</CODE> - the Transform3D to receive the left transform<DD><CODE>coe2ipr</CODE> - the Transform3D to receive the right transform, or null</DL>
</DD>
</DL>
<HR>

<A NAME="getViewPlatformToCoexistence(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D)"><!-- --></A><H3>
getViewPlatformToCoexistence</H3>
<PRE>
public void <B>getViewPlatformToCoexistence</B>(<A HREF="../../../../../javax/media/j3d/Canvas3D.html" title="class in javax.media.j3d">Canvas3D</A>&nbsp;c3d,
                                         <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;vp2coe)</PRE>
<DL>
<DD>Gets the current transform from view platform coordinates to
 coexistence coordinates and copies it into the given transform.        View
 platform coordinates are always aligned with coexistence coordinates
 but may differ in scale and in Y and Z offset.  The scale is derived
 from the window resize and screen scale policies, while the offset is
 derived from the view attach policy.<p>

 Java 3D constructs a view from the physical position of the eyes
 relative to the physical positions of the image plates; it then uses a
 view platform to position that physical configuration into the virtual
 world and from there computes the correct projections of the virtual
 world onto the physical image plates.  Coexistence coordinates are used
 to place the physical positions of the view platform, eyes, head, image
 plate, sensors, and tracker base in relation to each other. The view
 platform is positioned with respect to the virtual world through the
 scene graph, so the view platform to coexistence transform defines the
 space in which the virtual world and physical world coexist.<p>
 
 This method requires a Canvas3D.        A different transform may be returned
 for each canvas in the view if any of the following apply:<p><ul>

 <li>The window resize policy is <code>PHYSICAL_WORLD</code>, which
           alters the scale depending upon the width of the canvas.</li><p>

 <li>The screen scale policy is <code>SCALE_SCREEN_SIZE</code>,
           which alters the scale depending upon the width of the screen
           associated with the canvas.</li><p>

 <li>A window eyepoint policy of <code>RELATIVE_TO_FIELD_OF_VIEW</code>
           with a view attach policy of <code>NOMINAL_HEAD</code> in effect,
           which sets the view platform Z offset in coexistence coordinates
           based on the width of the canvas.  These are the default policies.
           The offset also follows the width of the canvas when the
           <code>NOMINAL_FEET</code> view attach policy is used.</li></ul>
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>c3d</CODE> - the Canvas3D to use<DD><CODE>vp2coe</CODE> - the Transform3D to receive the transform</DL>
</DD>
</DL>
<HR>

<A NAME="getCoexistenceToViewPlatform(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D)"><!-- --></A><H3>
getCoexistenceToViewPlatform</H3>
<PRE>
public void <B>getCoexistenceToViewPlatform</B>(<A HREF="../../../../../javax/media/j3d/Canvas3D.html" title="class in javax.media.j3d">Canvas3D</A>&nbsp;c3d,
                                         <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;coe2vp)</PRE>
<DL>
<DD>Gets the current transform from coexistence coordinates to
 view platform coordinates and copies it into the given transform.<p>

 This method requires a Canvas3D.        The returned transform may differ
 across canvases for the same reasons as discussed in the description of
 <code>getViewPlatformToCoexistence</code>.<p>
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>c3d</CODE> - the Canvas3D to use<DD><CODE>coe2vp</CODE> - the Transform3D to receive the transform<DT><B>See Also:</B><DD><A HREF="../../../../../com/sun/j3d/utils/universe/ViewInfo.html#getViewPlatformToCoexistence(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D)"><CODE>getViewPlatformToCoexistence(Canvas3D, Transform3D)</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="getCoexistenceToVworld(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D)"><!-- --></A><H3>
getCoexistenceToVworld</H3>
<PRE>
public void <B>getCoexistenceToVworld</B>(<A HREF="../../../../../javax/media/j3d/Canvas3D.html" title="class in javax.media.j3d">Canvas3D</A>&nbsp;c3d,
                                   <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;coe2vw)</PRE>
<DL>
<DD>Gets the current transform from coexistence coordinates to virtual
 world coordinates and copies it into the given transform.<p>

 The View must be attached to a ViewPlatform which is part of a live
 scene graph, and the ViewPlatform node must have its
 <code>ALLOW_LOCAL_TO_VWORLD_READ</code> capability set.<p>

 This method requires a Canvas3D.        The returned transform may differ
 across canvases for the same reasons as discussed in the description of
 <code>getViewPlatformToCoexistence</code>.<p>
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>c3d</CODE> - the Canvas3D to use<DD><CODE>coe2vw</CODE> - the Transform3D to receive the transform<DT><B>See Also:</B><DD><A HREF="../../../../../com/sun/j3d/utils/universe/ViewInfo.html#getViewPlatformToCoexistence(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D)"><CODE>getViewPlatformToCoexistence(Canvas3D, Transform3D)</CODE></A></DL>
</DD>
</DL>
<HR>

<A NAME="getEyeToImagePlate(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D, javax.media.j3d.Transform3D)"><!-- --></A><H3>
getEyeToImagePlate</H3>
<PRE>
public void <B>getEyeToImagePlate</B>(<A HREF="../../../../../javax/media/j3d/Canvas3D.html" title="class in javax.media.j3d">Canvas3D</A>&nbsp;c3d,
                               <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;e2ipl,
                               <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;e2ipr)</PRE>
<DL>
<DD>Gets the transforms from eye coordinates to image plate coordinates and
 copies them into the Transform3Ds specified.<p>
 
 When head tracking is used the eye positions are taken from the head
 position and set in relation to the image plates with each Screen3D's
 <code>trackerBaseToImagePlate</code> transform.        Otherwise the window
 eyepoint policy is used to derive the eyepoint relative to the image
 plate.  When using a head mounted display the eye position is
 determined solely by calibration constants in Screen3D and
 PhysicalBody; see the source code for the private method
 <code>getEyesHMD</code> for more information.<p>
 
 Eye coordinates are always aligned with image plate coordinates, so
 these transforms are always just translations.  With a monoscopic
 canvas the eye transform is copied to the first argument and the second
 argument is not used.  For a stereo canvas the first argument receives
 the left eye transform, and if the second argument is non-null it
 receives the right eye transform.
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>c3d</CODE> - the Canvas3D associated with the image plate<DD><CODE>e2ipl</CODE> - the Transform3D to receive left transform<DD><CODE>e2ipr</CODE> - the Transform3D to receive right transform, or null</DL>
</DD>
</DL>
<HR>

<A NAME="getEyeToViewPlatform(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D, javax.media.j3d.Transform3D)"><!-- --></A><H3>
getEyeToViewPlatform</H3>
<PRE>
public void <B>getEyeToViewPlatform</B>(<A HREF="../../../../../javax/media/j3d/Canvas3D.html" title="class in javax.media.j3d">Canvas3D</A>&nbsp;c3d,
                                 <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;e2vpl,
                                 <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;e2vpr)</PRE>
<DL>
<DD>Gets the current transforms from eye coordinates to view platform
 coordinates and copies them into the given Transform3Ds.<p>
 
 With a monoscopic canvas the eye transform is copied to the first
 argument and the second argument is not used.  For a stereo canvas the
 first argument receives the left eye transform, and if the second
 argument is non-null it receives the right eye transform.<p>

 This method requires a Canvas3D.        When using a head mounted display,
 head tracking with fixed screens, or a window eyepoint policy of
 <code>RELATIVE_TO_COEXISTENCE</code>, then the transforms returned may
 be different for each canvas if stereo is not in use and they have
 different monoscopic view policies.  They may additionally differ in
 scale across canvases with the <code>PHYSICAL_WORLD</code> window
 resize policy or the <code>SCALE_SCREEN_SIZE</code> screen scale
 policy, which alter the scale depending upon the width of the canvas or
 the width of the screen respectively.<p>
 
 With window eyepoint policies of <code>RELATIVE_TO_FIELD_OF_VIEW</code>,
 <code>RELATIVE_TO_SCREEN</code>, or <code>RELATIVE_TO_WINDOW</code>,
 then the transforms returned may differ across canvases due to
 the following additional conditions:<p><ul>
 
 <li>The window eyepoint policy is <code>RELATIVE_TO_WINDOW</code> or
           <code>RELATIVE_TO_SCREEN</code>, in which case the manual eye
           position in image plate can be set differently for each
           canvas.</li><p>

 <li>The window eyepoint policy is <code>RELATIVE_TO_FIELD_OF_VIEW</code>
           and the view attach policy is <code>NOMINAL_SCREEN</code>, which
           decouples the view platform's canvas Z offset from the eyepoint's
           canvas Z offset.</li><p> 

 <li>The eyepoint X and Y coordinates are centered in the canvas with a
           window eyepoint policy of <code>RELATIVE_TO_FIELD_OF_VIEW</code>
           or <code>RELATIVE_TO_WINDOW</code>, and a window movement policy
           of <code>VIRTUAL_WORLD</code> centers the view platform's X and Y
           coordinates to the middle of the screen.</li><p>

 <li>Coexistence centering is set false, which allows each canvas and
           screen to have a different position with respect to coexistence
           coordinates.</li></ul>
<P>
<DD><DL>
<DT><B>Parameters:</B><DD><CODE>c3d</CODE> - the Canvas3D to use<DD><CODE>e2vpl</CODE> - the Transform3D to receive the left transform<DD><CODE>e2vpr</CODE> - the Transform3D to receive the right transform, or null</DL>
</DD>
</DL>
<HR>

<A NAME="getViewPlatformToEye(javax.media.j3d.Canvas3D, javax.media.j3d.Transform3D, javax.media.j3d.Transform3D)"><!-- --></A><H3>
getViewPlatformToEye</H3>
<PRE>
public void <B>getViewPlatformToEye</B>(<A HREF="../../../../../javax/media/j3d/Canvas3D.html" title="class in javax.media.j3d">Canvas3D</A>&nbsp;c3d,
                                 <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;vp2el,
                                 <A HREF="../../../../../javax/media/j3d/Transform3D.html" title="class in javax.media.j3d">Transform3D</A>&nbsp;vp2er)</PRE>
<DL>
<DD>Gets the current transf