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<p class="Normal">You can light a scene with distant lights (which act like point-like lamps far from the scene) and/or local lights (point-like lamps near the scene, like the yellow light shown above). For a distant light you specify its direction from the origin. For a local light you specify its location in the scene.</p>
<p class="Normal"><span class="attributes">There is a list of all distant and local light
objects, </span><span class="attribute">scene.lights</span><span class="attributes">. By default, </span><span class="attribute">scene.lights</span><span class="attributes"> is this list:<br />
</span></p>
<p class="program style6"> [distant_light(direction=(0.22, 0.44, 0.88), color=color.gray(0.8)),<br />
distant_light(direction=(-0.88, -0.22, -0.44),
color=color.gray(0.3))]</p>
<p class="Normal"><span class="attributes"> These are equivalent to the default lights in Visual prior to version
5. </span>You can get rid of these default lights by setting the list to empty with <span class="attribute">scene.lights
= []</span>.</p>
<p class="Normal">In addition to these default distant lights, there is default ambient lighting in the form of <font color="#FF0000">scene.ambient=color.gray(0.2)</font>; for compatibility with earlier versions of Visual, this can
be expressed as scene.ambient=0.2, but now the ambient light can be specified as any color you want. The
color of light objects and the amount of <font color="#FF0000">scene.ambient</font> must
be specified with some care, because if the total lighting intensity
exceeds 1 anywhere in the scene the results are unpredictable.</p>
<p class="Normal">The following statement creates a local yellow light whose <em>position</em> is at
(x,y,z), and if you continually update lamp.pos, the light will move.
You may wish to place a sphere or box with <span class="attribute">material=materials.emissive</span> at the same location so that the lamp looks like a glowing lamp.</p>
<p class="program"> lamp = local_light(pos=(x,y,z), color=color.yellow)</p>
<p class="Normal">A distant red light located in the <em>direction</em> (x,y,z) from the origin is created like this:</p>
<p class="program">distant_light(direction=(x,y,z), color=color.red)</p>
<p class="Normal"> Previous to Visual 5, you set
up a light by specifying a vector in the direction to the light
from the origin, and the magnitude of the vector was the intensity.
For example, <span class="attribute">scene.lights
= [vector(1,0,0)]</span> with <span class="attribute">scene.ambient
= 0</span> would light the scene with full intensity from the right
side, with no ambient lighting. In Visual
5 and later, this scheme for specifying lights still works, but
this compatibility syntax actually creates distant_light objects.</p>
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