<h1>Module Scientific.Visualization.VRML2</h1>





<p>This module provides definitions of simple 3D graphics objects and
VRML scenes containing them. The objects are appropriate for data
visualization, not for virtual reality modelling. Scenes can be written
to VRML files or visualized immediately using a VRML browser, whose
name is taken from the environment variable VRML2VIEWER (under Unix).</p>



There are a few attributes that are common to all graphics objects:

<p><dl>


<dt>material</dt>


<dd><p>
a Material object defining color and surface properties</p></dd>


<dt>comment</dt>


<dd><p>
a comment string that will be written to the VRML file</p></dd>


<dt>reuse</dt>


<dd><p>
a boolean flag (defaulting to false). If set to one,
           the object may share its VRML definition with other
           objects. This reduces the size of the VRML file, but
           can yield surprising side effects in some cases.</p></dd>


</dl>
</p>





<p>This module used the VRML 2.0 definition, also known as VRML97. For
the original VRML 1, use the module VRML, which uses exactly the same
interface. There is another almost perfectly compatible module VMD,
which produces input files for the molecular visualization program
VMD.</p>



<p>Example:</p>



<pre>
from Scientific.Visualization.VRML2 import *
scene = Scene([])
scale = ColorScale(10.)
for x in range(11):
    color = scale(x)
    scene.addObject(Cube(Vector(x, 0., 0.), 0.2,
                         material=Material(diffuse_color = color)))
scene.view()
</pre>
























<hr width=70%>
<h2>Functions</h2>





<ul>


<li> <p>

<b><i>DiffuseMaterial</i></b>()<br>


</p>



<p>Returns a material with the <tt>diffuse color</tt> attribute set to <i>color</i>.</p>

<li> <p>

<b><i>EmissiveMaterial</i></b>()<br>


</p>



<p>Returns a material with the <tt>emissive color</tt> attribute set to <i>color</i>.</p>

</ul>




<hr width=70%>
<h2>Class Scene: VRML scene</h2>





<p>A VRML scene is a collection of graphics objects that can be
written to a VRML file or fed directly to a VRML browser.</p>



<p>Constructor: Scene(<i>objects</i>=None, <i>cameras</i>=None, **|options|)</p>



<p><dl>


<dt><i>objects</i></dt>


<dd><p>
a list of graphics objects or <tt>None</tt> for an empty scene</p></dd>


<dt><i>cameras</i></dt>


<dd><p>
a list of cameras</p></dd>


<dt><i>options</i></dt>


<dd><p>
options as keyword arguments (none defined at the moment;
             this argument is provided for compatibility with
             other modules)
</p></dd>


</dl>
</p>



<b>Methods:</b><br>
<ul>
<li> <b><i>addObject</i></b>(<i>object</i>)




<p>Adds <i>object</i> to the list of graphics objects.</p>





<li> <b><i>addCamera</i></b>(<i>camera</i>)




<p>Adds <i>camera</i> to the list of cameras.</p>





<li> <b><i>writeToFile</i></b>(<i>filename</i>)




<p>Writes the scene to a VRML file with name <i>filename</i>.</p>





<li> <b><i>view</i></b>()


<p>Start a VRML browser for the scene.</p>





</ul>
<hr width=70%>
<h2>Class Camera: Camera/viewpoint for a scene</h2>





<p>Constructor: Camera(<i>position</i>, <i>orientation</i>, <i>description</i>,
                    <i>field_of_view</i>)</p>



<p><dl>


<dt><i>position</i></dt>


<dd><p>
the location of the camera (a vector)</p></dd>


<dt><i>orientation</i></dt>


<dd><p>
an (axis, angle) tuple in which the axis is
                 a vector and angle a number (in radians);
                 axis and angle specify a rotation with respect
                 to the standard orientation along the negative z axis</p></dd>


<dt><i>description</i></dt>


<dd><p>
a label for the viewpoint (a string)</p></dd>


<dt><i>field_of_view</i></dt>


<dd><p>
the field of view (a positive number)
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class NavigationInfo: Navigation Information</h2>





<p>Constructor: NavigationInfo(<i>speed</i>, <i>type</i>)</p>



<p><dl>


<dt><i>speed</i></dt>


<dd><p>
walking speed in length units per second</p></dd>


<dt><i>type</i></dt>


<dd><p>
one of <tt>WALK</tt>, <tt>EXAMINE</tt>, <tt>FLY</tt>, <tt>NONE</tt>, <tt>ANY</tt>

</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class Sphere: Sphere</h2>





<p>Constructor: Sphere(<i>center</i>, <i>radius</i>, **|attributes|)</p>



<p><dl>


<dt><i>center</i></dt>


<dd><p>
the center of the sphere (a vector)</p></dd>


<dt><i>radius</i></dt>


<dd><p>
the sphere radius (a positive number)</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class Cube: Cube</h2>





<p>Constructor: Cube(<i>center</i>, <i>edge</i>, **|attributes|)</p>



<p><dl>


<dt><i>center</i></dt>


<dd><p>
the center of the cube (a vector)</p></dd>


<dt><i>edge</i></dt>


<dd><p>
the length of an edge  (a positive number)</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute</p></dd>


</dl>
</p>



<p>The edges of a cube are always parallel to the coordinate axes.
</p>



<hr width=70%>
<h2>Class Cylinder: Cylinder</h2>





<p>Constructor: Cylinder(<i>point1</i>, <i>point2</i>, <i>radius</i>,
                      <i>faces</i>=<tt>(1, 1, 1)</tt>, **|attributes|)</p>



<p><dl>


<dt><i>point1</i>, <i>point2</i></dt>


<dd><p>
the end points of the cylinder axis (vectors)</p></dd>


<dt><i>radius</i></dt>


<dd><p>
the radius  (a positive number)</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute</p></dd>


<dt><i>faces</i></dt>


<dd><p>
a sequence of three boolean flags, corresponding to
           the cylinder hull and the two circular end pieces,
           specifying for each of these parts whether it is visible
           or not.
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class Cone: Cone</h2>





<p>Constructor: Cone(<i>point1</i>, <i>point2</i>, <i>radius</i>, <i>face</i>=<tt>1</tt>, **|attributes|)</p>



<p><dl>


<dt><i>point1</i>, <i>point2</i></dt>


<dd><p>
the end points of the cylinder axis (vectors).
                      <i>point1</i> is the tip of the cone.</p></dd>


<dt><i>radius</i></dt>


<dd><p>
the radius  (a positive number)</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute</p></dd>


<dt><i>face</i></dt>


<dd><p>
a boolean flag, specifying if the circular bottom is visible
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class Line: Line</h2>





<p>Constructor: Line(<i>point1</i>, <i>point2</i>, **|attributes|)</p>



<p><dl>


<dt><i>point1</i>, <i>point2</i></dt>


<dd><p>
the end points of the line (vectors)</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class PolyLines: Multiple connected lines</h2>





<p>Constructor: PolyLines(<i>points</i>, **|attributes|)</p>



<p><dl>


<dt><i>points</i></dt>


<dd><p>
a sequence of points to be connected by lines</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class Polygons: Polygons</h2>





<p>Constructor: Polygons(<i>points</i>, <i>index_lists</i>, **|attributes|)</p>



<p><dl>


<dt><i>points</i></dt>


<dd><p>
a sequence of points</p></dd>


<dt><i>index_lists</i></dt>


<dd><p>
a sequence of index lists, one for each polygon.
                 The index list for a polygon defines which points
                 in <i>points</i> are vertices of the polygon.</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class Arrow: Arrow</h2>





<p>An arrow consists of a cylinder and a cone.</p>



<p>Constructor: Arrow(<i>point1</i>, <i>point2</i>, <i>radius</i>, **|attributes|)</p>



<p><dl>


<dt><i>point1</i>, <i>point2</i></dt>


<dd><p>
the end points of the arrow (vectors).
                      <i>point2</i> defines the tip of the arrow.</p></dd>


<dt><i>radius</i></dt>


<dd><p>
the radius of the arrow shaft (a positive number)</p></dd>


<dt><i>attributes</i></dt>


<dd><p>
any graphics object attribute
</p></dd>


</dl>
</p>



<hr width=70%>
<h2>Class Material: Material for graphics objects</h2>





<p>A material defines the color and surface properties of an object.</p>



<p>Constructor: Material(**|attributes|)</p>



<p>The attributes are "ambient_color", "diffuse_color", "specular_color",
"emissive_color", "shininess", and "transparency".
</p>