diff options
| author | Travis CI <zmoelnig@travis-ci.umlaeute.mur.at> | 2015-03-17 22:38:45 +0000 |
|---|---|---|
| committer | Travis CI <zmoelnig@travis-ci.umlaeute.mur.at> | 2015-03-17 22:38:45 +0000 |
| commit | 356f94fc355f36c16e48555d10c2377dff4b7554 (patch) | |
| tree | 4b825dc642cb6eb9a060e54bf8d69288fbee4904 /Gem/manual/Lighting.html | |
| parent | 5c694f159b012d1d94bf15bfe580dec52e4fe797 (diff) | |
Gem 096ed6ef786b7a9d6e11a437ff8526619c89a1fd osx/x86_64
built 'coverity_scan:096ed6ef786b7a9d6e11a437ff8526619c89a1fd' for osx/x86_64
Diffstat (limited to 'Gem/manual/Lighting.html')
| -rw-r--r-- | Gem/manual/Lighting.html | 107 |
1 files changed, 0 insertions, 107 deletions
diff --git a/Gem/manual/Lighting.html b/Gem/manual/Lighting.html deleted file mode 100644 index dcff171..0000000 --- a/Gem/manual/Lighting.html +++ /dev/null @@ -1,107 +0,0 @@ -<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
-<html>
-<head>
- <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
- <meta name="Author" content="Mark Danks">
- <meta name="Author" content="IOhannes m zmölnig">
- <title>Lighting</title>
-</head>
-<body>
-
-<center>
-<h2>
-<u>Lighting</u></h2></center>
-Lighting is an important factor is how we perceive the quality of an image.
-For example, without lighting and shading, a sphere would just look like
-a circle. GEM provides two types of lights, a local light and world
-light.
-<p>OpenGL uses a vertex lighting model. This means that for every
-vertex in the scene, the influence of the light is calculated. The
-color for the polygon is then modified by the light value of all of the
-vertices. This generally produces a very smooth effect, but you will
-occasionally run into rendering artifacts, especially if you use local
-lights. For example, imagine you have a local light close a large
-square. The corners of the square are far away from the light, so
-none of them will be lit very brightly, even though the light itself is
-very close to the surface of the square.
-<p>It is important to realize that lighting is an expensive operation to
-use. The number of polygons that you will be able to render will
-be much lower if lighting is turned on. As usual, the complexity
-of the scene and the speed of your computer and graphics card will greatly
-affect your frame rate.
-<p>GEM has only a maximum of 8 lights at one time. If you try to
-create more lights than that, you will get an error message.
-<p><a href="#Activate">Activate lighting</a>
-<br><a href="#world_light">[world_light]</a> - A directional light
-<br><a href="#light">[light]</a> - A point light in the world
-<br><a href="#Moving">Moving lights</a>
-<p><img SRC="tribar.gif" height=13 width=561>
-<h3>
-<a NAME="Activate"></a>Activate lighting</h3>
-Lighting is activated by sending a message to <i>[gemwin]</i>. If you
-send "lighting 1", then lighting will be turned on. If you send "lighting
-0", then lighting will be turned off. The lighting state is kept
-even if you destroy the gemwin. This means that if you close a patch
-and open another one, the lighting will still be the same.
-<p>Individual lights can be turned on and off by sending a 1 or 0 to the
-left inlet of the light object itself.
-<p><img SRC="tribar.gif" height=13 width=561>
-<h3>
-<a NAME="world_light"></a>[world_light]</h3>
-A <i>[world_light]</i> is a light which exists infintely far away.
-This reduces the computation needed, so your patch can run faster, but
-it means that all of the light rays are parallel. The <i>[world_light]</i>
-is good for objects like the sun and other lighting affects. This
-means that translating a <i>[world_light]</i> has no effect, although rotation
-does.
-<p>The following patch is 03.lighting/01.world_light.pd.
-<center>
-<p><img SRC="world_light.jpg" BORDER=1 height=152 width=370></center>
-
-<p>The <i>[world_light]</i> has one extra inlet. The right inlet accepts
-three floats to set the color of the light. A <i>[color]</i> object
-would do nothing. In this case, the light is being set to purple.
-The <i>[world_light]</i> also accepts a debug message. The debug message
-turns on and off a graphical representation of the light in the scene.
-The <i>[world_light]</i> looks like a cone. The cone shows the direction
-that the light is coming from. Remember that the actual position
-of the light does not matter, so geos behind the cone will still be lit.
-It is the direction of the light that matters. This is why you can
-rotate the light.
-<p><img SRC="tribar.gif" height=13 width=561>
-<h3>
-<a NAME="light"></a>[light]</h3>
-A <i>[light]</i> object generates a point light in the world. Because
-the light is local to the scene, there is more math to generate the effect
-of the light on the vertices. However, unlike a <i>[world_light]</i>,
-you can translate the <i>[light]</i> object.
-<p>Below is the patch 03.lighting/02.light.pd.
-<center>
-<p><img SRC="light.jpg" BORDER=1 height=215 width=212></center>
-
-<p>The <i>[light]</i> object has a right inlet for the color, just light
-the <i>[world_light]</i> object. As this patch shows, the light can
-be moved around the scene with both <i>[rotate]</i> and <i>[translate]</i>
-objects. If you were to set the translate X value equal to 1.0, then
-the sphere would not be lit at all. This is because the light would
-be inside of the sphere. When you turn on the debug representation,
-it is a sphere with its origin where the light it. The <i>[light]</i>
-object does not have any size. It exists as a point source.
-<p><img SRC="tribar.gif" height=13 width=561>
-<h3>
-<a NAME="Moving"></a>Moving lights</h3>
-The patch 03.lighting/03.controlLights.pd allows you to move a <i>[light]</i>
-and <i>[world_light]</i> object in the same scene to see the difference between
-the two objects.
-<p>The patch 03.lighting/04.moveSpheres.pd is an example which moves
-two spheres around the world. Turn on and off the individual lights
-for a demonstration of a local versus infinite light.
-<p>The patch 03.lighting/05.materials.pd uses the material objects to
-selectively control the color of the object. Notice that the diffuse object
-sets the "overall" color, while the specular objects sets the bright reflective
-area where the light directly shines.
-<p><img SRC="tribar.gif" height=13 width=561>
-<p><a href="index.html">[return]</a>
-<br>
-</body>
-</html>
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