config-syntax.html

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unexpectedly when the virtual world scaling changed as the result of a window
resize.  The quirk can be avoided by using the <code>VIRTUAL_EYE</code> or
<code>VIRTUAL_SCREEN</code> clip policies or by using the
<code>VIRTUAL_WORLD</code> resize policy, but in most cases the effect is
benign and doesn't lead to unexpected results.</p>

<h4>
<a NAME="FieldOfView"></a>FieldOfView</h4>
This number is the view's horizontal field of view in radians.  The default
value is PI/4.  This value is ignored if WindowEyepointPolicy is not
<code>RELATIVE_TO_FIELD_OF_VIEW</code> or if head tracking is enabled.  The
eyepoint for each canvas associated with the view is set such that it is
centered in X and Y, with the Z value at the appropriate distance to match the
specified field of view across the width of the canvas.

<h4>
<a NAME="StereoEnable"></a>StereoEnable</h4>
Enable or disable stereo viewing for this view according to the boolean value
specified by the <i>property value</i> string.  The default value is false.
<p>
There is no actual method in the core Java 3D View or utility Viewer class to
enable stereo.  A true value for this property causes ConfigContainer to
attempt to create stereo-capable canvases for all the screens associated with
this view.  Stereo will then be enabled for each canvas successfully created
with stereo capability.</p>

<h4>
<a NAME="TrackingEnable"></a>TrackingEnable</h4>
Enable or disable head tracking for this view according to the boolean value
specified by the <i>property value</i> string.  The default value is false.
<p>
Setting this property true causes WindowEyepointPolicy to be ignored; it will
effectively be <code>RELATIVE_TO_COEXISTENCE</code> with the eyepoint in
coexistence coordinates computed from reading the head tracking sensor.
Tracking must be made available by registering an input device and a head
tracking sensor in PhysicalEnvironment.</p>

<h4>
<a NAME="AntialiasingEnable"></a>AntialiasingEnable</h4>
Enable or disable scene antialiasing for this view according to the boolean
value specified by the <i>property value</i> string.  The default value is
false.
<p>
A true value for this property causes ConfigContainer to attempt to create
a canvas capable of scene antialiasing on each screen associated with this
view.  The scene will then be antialiased on each canvas successfully created
with that capability.</p>
<p>
Line and point antialiasing are independent of scene antialiasing and are
controlled by the LineAttribute and PointAttribute components of an Appearance.
If line and point antialiasing is enabled, then they will be antialiased prior
to scene antialiasing; if scene antialiasing is turned off, then antialiased
lines and points will still be antialiased.</p>
</blockquote>
<hr>

<h2>
<a NAME="NewViewPlatform"></a>NewViewPlatform</h2>
<b>Syntax:</b>
<br>(NewViewPlatform <i>&lt;instance name&gt;</i>
[Alias <i>&lt;alias name&gt;</i>])
<p>
Creates a new view platform and binds it to the name given by <i>instance
name</i>.  In the configuration file the term <i>view platform</i> refers to an
instance of the <a href="../ViewingPlatform.html">ViewingPlatform</a> utility
class, which is an extension of BranchGroup containing an instance of a core
Java 3D ViewPlatform class.</p>
<p>
The last two arguments are optional and define an alias for <i>instance
name</i>.  This is useful in providing a longer descriptive name for the
application to recognize, or conversely, to provide a shorter alias for a
longer instance name.  Either name may be used to identify the instance.</p>
<hr>

<h2>
<a NAME="ViewPlatformProperty"></a>ViewPlatformProperty</h2>
<b>Syntax:</b>
<br>(ViewPlatformProperty <i>&lt;instance name&gt; &lt;property name&gt;
&lt;property value&gt;</i>)
<p>
Sets a ViewPlatform property.  The instance is specified by <i>instance
name</i>, the property to be set by <i>property name</i>, and the value to be
set by <i>property value</i>.  The following properties are configurable:</p>

<blockquote>
<h4>
<a NAME="NominalViewingTransform"></a>NominalViewingTransform</h4>
The <i>property value</i> is a boolean string indicating whether or not
the view platform should be backed up in Z to allow objects at the origin to be
viewed.  This only has effect if the ViewAttachPolicy is
<code>NOMINAL_HEAD</code>.  The default value is false.  See the
<a href="../ViewingPlatform.html#setNominalViewingTransform()">setNominalViewingTransform</a>
method of ViewingPlatform.

<h4>
<a NAME="InitialViewingTransform"></a>InitialViewingTransform</h4>
Sets the initial transform of the view platform to the 4D matrix
specified by <i>property value</i>.  The default value is identity.

<h4>
<a NAME="AllowPolicyRead"></a>AllowPolicyRead</h4>
The <i>property value</i> is a boolean string indicating whether or not reading
the ViewAttachPolicy is allowed.  The default value is false.

<h4>
<a NAME="AllowLocalToVworldRead"></a>AllowLocalToVworldRead</h4>
The <i>property value</i> is a boolean string indicating whether or not reading
the view platform's localToVworld transform is allowed.  The default value is
false. 

<h4>
<a NAME="ViewPlatformBehavior"></a>ViewPlatformBehavior</h4>
Attaches a ViewPlatformBehavior instantiated by 
<a href="#NewViewPlatformBehavior">NewViewPlatformBehavior</a>.
The <i>property value</i> string is the name bound to that instance.

<h4>
<a NAME="ViewAttachPolicy"></a>ViewAttachPolicy</h4>
The <i>property value</i> string can be one of <code>NOMINAL_SCREEN,
NOMINAL_HEAD,</code> or <code>NOMINAL_FEET</code>.  This establishes the point
in coexistence coordinates where the origin of view platform coordinates is
attached.  The basis vectors of view platform coordinates are always aligned
with those of coexistence coordinates.
<p>
For a ViewAttachPolicy of <code>NOMINAL_SCREEN</code>, the ViewPlatform origin
is set directly to the origin of coexistence, so that ViewPlatform coordinates
and coexistence coordinates are identical except for scale.</p>
<p>
For a ViewAttachPolicy of <code>NOMINAL_HEAD</code>, the ViewPlatform origin is
set to the origin of the nominal head, the center eye halfway between the left
and right eyes.  The nominal head origin is on the Z axis of coexistence
coordinates at some offset from the coexistence origin.  If the
WindowEyepointPolicy is <code>RELATIVE_TO_FIELD_OF_VIEW</code>, then this is
the positive Z offset producing the required field of view relative to the
width of the canvas at the coexistence origin, tracking the Z offset of the
eyepoint defined by that policy; otherwise, the Z offset is the
NominalEyeOffsetFromNominalScreen property of PhysicalBody and is decoupled
from the actual eyepoint offset.</p>
<p>
For a ViewAttachPolicy of <code>NOMINAL_FEET</code>, the ViewPlatform origin is
at the ground plane, which is NominalEyeHeightFromGround meters along -Y from
the origin of the nominal head.  NominalEyeHeightFromGround is a property of
PhysicalBody.</p>
<p>
<b>Note:</b> The normal Java 3D default is <code>NOMINAL_HEAD</code>.  When
using a configuration file, the default is <code>NOMINAL_HEAD</code> only if
every view attached to the view platform has a WindowEyepointPolicy of
<code>RELATIVE_TO_FIELD_OF_VIEW</code>; otherwise, the default is
<code>NOMINAL_SCREEN</code>.  If the view policy is <code>HMD_VIEW</code>, then
the ViewAttachPolicy is ignored and is always effectively
<code>NOMINAL_SCREEN</code>.</p>
</blockquote>
<hr>

<h2>
<a NAME="NewViewPlatformBehavior"></a>NewViewPlatformBehavior</h2>
<b>Syntax:</b>
<br>(NewViewPlatformBehavior <i>&lt;instance name&gt; &lt;class name&gt;</i>
[Alias <i>&lt;alias name&gt;</i>])
<p>
This command instantiates the concrete subclass of ViewPlatformBehavior
specified by the fully qualified <i>class name</i> and binds it to <i>instance
name</i>.  The ViewPlatformBehavior is instantiated through introspection of
the class name.  The subclass must provide a parameterless constructor.  If no
such constructor is available, then the behavior must be extended or wrapped to
provide one and the derived class used instead.</p>
<p>
The last two arguments are optional and define an alias for <i>instance
name</i>.  This is useful in providing a longer descriptive name for the
application to recognize, or conversely, to provide a shorter alias for a
longer instance name.  Either name may be used to identify the instance.</p>
<p>
View platform behaviors often need sensors or canvases as event sources to
drive the behavior action.  A subclass of ViewPlatformBehavior always gets the
current ViewingPlatform through its 
<a href="../../behaviors/vp/ViewPlatformBehavior.html#setViewingPlatform(com.sun.j3d.utils.universe.ViewingPlatform)">setViewingPlatform</a>
method.  When the behavior is initialized, the canvases used by the
ViewingPlatform can be retrieved by calling its 
<a href="../ViewingPlatform.html#getViewers()">getViewers</a> method and
then calling each Viewer's 
<a href="../Viewer.html#getCanvas3Ds()">getCanvas3Ds</a> method.  Sensors 
can be retrieved by calling the ViewingPlatform method 
<a href="../ViewingPlatform.html#getUniverse()">getUniverse</a>, checking 
to see if the returned SimpleUniverse is a ConfiguredUniverse, and then calling
its 
<a href="../ConfiguredUniverse.html#getNamedSensors()">getNamedSensors</a>
method.</p> 
<p>
Alternatively, the behavior implementation can define its own properties 
and receive canvas and sensor instances directly through the
<a href="#Canvas3D">Canvas3D</a> and <a href="#Sensor">Sensor</a> built-in
commands.</p>
<hr>

<h2>
<a NAME="ViewPlatformBehaviorProperty"></a>ViewPlatformBehaviorProperty</h2>
<b>Syntax:</b>
<br>(ViewPlatformBehaviorProperty <i>&lt;instance name&gt;
&lt;property name&gt; &lt;property value&gt;</i>)
<p>
Sets a property of a ViewPlatformBehavior.  The instance is specified by
<i>instance name</i>, the property to be set by <i>property name</i>, and the
value to be set by <i>property value</i>.  The following properties are
pre-defined by the abstract ViewPlatformBehavior superclass and may be
configured directly:<p>

<blockquote>
<h4>
<a NAME="SchedulingBounds"></a>SchedulingBounds</h4>
The scheduling bounds for this behavior.  Use the 
<a href="#BoundingSphere">BoundingSphere</a> built-in command to set this
property.  The default is whatever the application or the concrete subclass
sets.

<h4>
<a NAME="SchedulingInterval"></a>SchedulingInterval</h4>
A number indicating the scheduling interval for this behavior. See the 
<a href="../../../../../../javax/media/j3d/Behavior.html#setSchedulingInterval(int)">setSchedulingInterval</a>
method of Behavior.

<h4>
<a NAME="HomeTransform"></a>HomeTransform</h4>
See the ViewPlatformBehavior method 
<a href="../../behaviors/vp/ViewPlatformBehavior.html#setHomeTransform(javax.media.j3d.Transform3D)">setHomeTransform</a>.
The property value must be a 4D matrix.
</blockquote>
<p>
The details of a concrete subclass of ViewPlatformBehavior are not known to
ConfigContainer, so any properties specific to the subclass are set by
using introspection to invoke <i>property name</i> as a method accepting an
array of Objects as its single parameter.  The arguments following the property
name are evaluated and the results passed to the method through that array of
Objects.  Such methods can usually be provided by extending or wrapping
existing ViewPlatformBehavior implementations.</p>
<hr>

<h2>
<a NAME="NewObject"></a>NewObject</h2>
<b>Syntax:</b>
<br>(NewObject <i>&lt;instance name&gt; &lt;class name&gt;</i>
[Alias <i>&lt;alias name&gt;</i>])
<p>
This command instantiates a generic object specified by <i>class
name</i> and binds it to <i>instance name</i>.  The object is instantiated
through introspection of the class name.  The object must provide a
parameterless constructor; this can usually be done by extending or
wrapping existing objects.</p> 
<p>
The last two arguments are optional and define an alias for <i>instance
name</i>.  This is useful in providing a longer descriptive name for the
application to recognize, or conversely, to provide a shorter alias for a
longer instance name.  Either name may be used to identify the instance.</p>
<p>
Objects so defined may be accessed from ConfigContainer through the
<a href="../ConfigContainer.html#getNamedGenericObjects()">getNamedGenericObjects</a> method.</p>
<hr>

<h2>
<a NAME="ObjectProperty"></a>ObjectProperty</h2>
<b>Syntax:</b>
<br>(ObjectProperty <i>&lt;instance name&gt; &lt;method name&gt; &lt;arg0&gt; 
... &lt;argn&gt;</i>)
<p>
Sets a property of a generic object.  The details of the object specified by
<i>instance name</i> are not known to ConfigContainer, so any parameters to be
set through the configuration file are passed to the object instance by
invoking <i>method name</i> through introspection.  The arguments