Documentation:Tutorial Section 3.7 - Revision history

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@@ Line 267: / Line 267: @@
 </ul>
-<p class="Note"><strong>Note:</strong> Previous versions of POV-Ray up to 3.6 inclusive did not provide the <code>emission</code> keyword, leading to the practice of using <code>ambient</code> instead. As of POV-Ray 3.7, this will no longer work, as <code>ambient_light</code> is effectively forced to zero when radiosity is enabled. For backward compatibility, an exception is made for scenes specifying a <code>#version</code> of 3.6 or earlier (or no version at all). In such scenes, it is strongly recommended to set the <code>ambient</code> of all materials to zero (unless you want them to emit light), or explicitly set <code>[[Reference:Global Settings#Ambient_Light|ambient_light]]</code> to zero.</p>
+<p class="Note"><strong>Note:</strong> Previous versions of POV-Ray up to v3.6 inclusive did not provide the <code>emission</code> keyword, leading to the practice of using <code>ambient</code> instead. As of POV-Ray v3.7, this will no longer work, as <code>ambient_light</code> is effectively forced to zero when radiosity is enabled. For backward compatibility, an exception is made for scenes specifying a <code>#version</code> of 3.6 or earlier (or no version at all). In such scenes, it is strongly recommended to set the <code>ambient</code> of all materials to zero (unless you want them to emit light), or explicitly set <code>[[Reference:Global Settings#Ambient_Light|ambient_light]]</code> to zero.</p>
 ====Radiosity with conventional lighting====

@@ Line 232: / Line 232: @@
 <p>With all these fancy effects the render times start becoming quite high, but unfortunately this is a price which has to be paid for such effects. </p>
 {{#indexentry:Radiosity, tutorial}}
-===Radiosity===
 ====Introduction====
 <p>Radiosity is a lighting technique to simulate the diffuse exchange of
@@ Line 268: / Line 269: @@
 <p class="Note"><strong>Note:</strong> Previous versions of POV-Ray up to 3.6 inclusive did not provide the <code>emission</code> keyword, leading to the practice of using <code>ambient</code> instead. As of POV-Ray 3.7, this will no longer work, as <code>ambient_light</code> is effectively forced to zero when radiosity is enabled. For backward compatibility, an exception is made for scenes specifying a <code>#version</code> of 3.6 or earlier (or no version at all). In such scenes, it is strongly recommended to set the <code>ambient</code> of all materials to zero (unless you want them to emit light), or explicitly set <code>[[Reference:Global Settings#Ambient_Light|ambient_light]]</code> to zero.</p>
 {{#indexentry:Radiosity, with conventional lighting}}
 <p>This section will introduce you to the technique of combining conventional and radiosity lighting. In this part of the tutorial, we'll be using basically the same sample scene that's located at <code>~/scenes/radiosity/radiosity2.pov</code>, however by changing various radiosity parameters, we'll be able to explore the effects that those changes can have on the scenes appearance and in some cases the render time. Later on, in this tutorial, you can find examples of [[Documentation:Tutorial Section 3.7#Radiosity without conventional lighting|pure radiosity]] illumination.</p>
@@ Line 879: / Line 880: @@
 </table>
 {{#indexentry:Radiosity, without conventional lighting}}
 <p>Radiosity also allows us to have scenes <em>without</em> conventional light sources. What's left is a situation that's similar to what you'd expect on a cloudy day where the light comes from no specific direction but from the whole sky.</p>
 <p>Reminder: The following settings are <em>still</em> in effect.</p>
@@ Line 1,401: / Line 1,402: @@
 </pre>
 {{#indexentry:Normals and Radiosity}}
 <p>When using a [[Reference:Radiosity#Normal and Radiosity|normal]]  statement in combination with radiosity lighting, you will see that the shadowed parts of the objects are totally smooth, no matter how strong the normals are made. The reason is that POV-Ray by default does not take the normal into account when calculating radiosity. You can easily change this by adding <code>normal on</code> to the radiosity block. Be aware that this can slow things down quite a bit and will require more memory, however it usually leads to more realistic results.</p>
@@ Line 1,433: / Line 1,434: @@
 </table>
 {{#indexentry:Radiosity performance considerations}}
 <p>High quality radiosity can be very slow. To some extent this is the price to pay for realistic lighting, but there are a lot of things that can be done to improve speed.</p>
@@ Line 1,472: / Line 1,473: @@
 our code to describe the motions of objects over time.</p>
 {{#indexentry:Animation, clock variable}}
 <p>POV-Ray supports an automatically declared floating point variable
 identified as <code>[[Reference:Numeric Expressions#Built-in Variables|clock]]</code> (all lower case). This is the key to making
@@ Line 1,572: / Line 1,573: @@
 with.</p>
 {{#indexentry:Animation, multi-stage}}
 <p>Okay, what if we wanted the ball to roll left to right for the first half
 of the animation, then change direction 135 degrees and roll right to left,
@@ Line 1,642: / Line 1,643: @@
 other motions.</p>
 {{#indexentry:phase, tutorial}}
 <p>There is another keyword we should know for purposes of animations: the
 <code>[[Reference:Pattern Modifiers#Frequency and Phase|phase]]</code> keyword. The phase keyword can be used on many texture

@@ Line 1,645: / Line 1,645: @@
 ====The Phase Keyword====
 <p>There is another keyword we should know for purposes of animations: the
-<code>[[Reference:Pattern#Frequency and Phase|phase]]</code> keyword. The phase keyword can be used on many texture
+<code>[[Reference:Pattern Modifiers#Frequency and Phase|phase]]</code> keyword. The phase keyword can be used on many texture
 elements, especially those that can take a color, pigment, normal or texture
 map. Remember the form that these maps take. For example:</p>

@@ Line 1,439: / Line 1,439: @@
 <p>If average to good quality radiosity will work for your scene, then it's probably a good idea to spend the time to find the <em>sweet spot</em> that strikes the best balance between quality and speed.  Especially <code>recursion_limit</code> should be kept as low as possible. Sometimes <code>1</code> is sufficient, if not <code>2</code> or <code>3</code> should often be enough.</p>
-<p>With high quality settings, radiosity data can take quite a lot of memory. Apart from that the other scene data is also used much more intensively than in a conventional scene. Therefore insufficient memory and swapping can slow down things even more. Here's a few [[Reference:Tracing Options|Radiosity Options|radiosity options]] that might help.</p>
+<p>With high quality settings, radiosity data can take quite a lot of memory. Apart from that the other scene data is also used much more intensively than in a conventional scene. Therefore insufficient memory and swapping can slow down things even more. Here's a few [[Reference:Tracing Options#Radiosity Options|radiosity options]] that might help.</p>
 <p>Finally the scene geometry and textures are important too. Objects not visible in the camera usually only increase parsing time and memory use, but in a radiosity scene, also objects behind the camera can slow down the rendering process. See the section [[Reference:Radiosity#Configuring Radiosity|Configuring Radiosity]] for some helpful hints.</p>

@@ Line 266: / Line 266: @@
 </ul>
-<p class="Note"><strong>Note:</strong> Previous versions of POV-Ray up to 3.6 inclusive did not provide the <code>emission</code> keyword, leading to the practice of using <code>ambient</code> instead. As of POV-Ray 3.7, this will no longer work, as <code>ambient_light</code> is effectively forced to zero when radiosity is enabled. For backward compatibility, an exception is made for scenes specifying a <code>#version</code> of 3.6 or earlier (or no version at all). In such scenes, it is strongly recommended to set the <code>ambient</code> of all materials to zero (unless you want them to emit light), or explicitly set [[Reference:Global Settings#Ambient_Light|<code>ambient_light</code>]] to zero.</p>
+<p class="Note"><strong>Note:</strong> Previous versions of POV-Ray up to 3.6 inclusive did not provide the <code>emission</code> keyword, leading to the practice of using <code>ambient</code> instead. As of POV-Ray 3.7, this will no longer work, as <code>ambient_light</code> is effectively forced to zero when radiosity is enabled. For backward compatibility, an exception is made for scenes specifying a <code>#version</code> of 3.6 or earlier (or no version at all). In such scenes, it is strongly recommended to set the <code>ambient</code> of all materials to zero (unless you want them to emit light), or explicitly set <code>[[Reference:Global Settings#Ambient_Light|ambient_light]]</code> to zero.</p>
 {{#indexentry:Radiosity, with conventional lighting}}

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@@ Line 240: / Line 240: @@
 calculated, all shadowed parts look totally flat.  Radiosity can help to
 overcome this limitation.  More details on the technical aspects can be
-found in the <!--<linkto "Radiosity">reference section</linkto>--->[[Documentation:Reference Section 3.2#Radiosity|reference section]].</p>
+found in the [[Reference:Radiosity|reference]] section.</p>
 <p>To enable radiosity, you have to add a radiosity block to the
@@ Line 246: / Line 246: @@
 simplistic ambient light but it takes much longer to compute, so it can be useful
 to switch off radiosity during scene development. You can use a declared constant
-or an <!--<linkto "constant">INI-file constant</linkto>--->[[Documentation:Reference Section 1.2#Constant|INI-file constant]] and an <code>#if</code> statement to do this:</p>
+or an [[Reference:Scene Parsing Options#Constant|INI-file constant]] and an <code>#if</code> statement to do this:</p>
 <pre>
    #declare RAD = off;
@@ Line 266: / Line 266: @@
 </ul>
-<p class="Note"><strong>Note:</strong> Previous versions of POV-Ray up to 3.6 inclusive did not provide the <code>emission</code> keyword, leading to the practice of using <code>ambient</code> instead. As of POV-Ray 3.7, this will no longer work, as <code>ambient_light</code> is effectively forced to zero when radiosity is enabled. For backward compatibility, an exception is made for scenes specifying a <code>#version</code> of 3.6 or earlier (or no version at all). In such scenes, it is strongly recommended to set the <code>ambient</code> of all materials to zero (unless you want them to emit light), or explicitly set <!--<linkto "ambient_light">ambient_light</linkto>--->[[Documentation:Reference Section 3.1#Ambient_Light|<code>ambient_light</code>]] to zero.</p>
+<p class="Note"><strong>Note:</strong> Previous versions of POV-Ray up to 3.6 inclusive did not provide the <code>emission</code> keyword, leading to the practice of using <code>ambient</code> instead. As of POV-Ray 3.7, this will no longer work, as <code>ambient_light</code> is effectively forced to zero when radiosity is enabled. For backward compatibility, an exception is made for scenes specifying a <code>#version</code> of 3.6 or earlier (or no version at all). In such scenes, it is strongly recommended to set the <code>ambient</code> of all materials to zero (unless you want them to emit light), or explicitly set [[Reference:Global Settings#Ambient_Light|<code>ambient_light</code>]] to zero.</p>
 {{#indexentry:Radiosity, with conventional lighting}}
@@ Line 295: / Line 295: @@
 <p>Finally, a few more things about the scene setup. All objects except the sky have <code>diffuse 0.65</code> and <code>emission 0</code> in their finish block. The sky sphere has a bright blue pigment (what a surprise) with <code>diffuse 0</code> and <code>emission 1.0</code> as finish attributes.</p>
-<p class="Note"><strong>Note:</strong> If using the <code>[[Documentation:Reference Section 3.1#Sky Sphere|sky_sphere]]</code> object, which does not support the <code>finish</code> keyword, instead of a <code>[[Documentation:Reference Section 4.1#Sphere|sphere]]</code> object that does, you will need define a <code>[[Documentation:Reference Section 2.5#The #default Directive|#default]]</code> finish in order to affect it's finish properties.</p>
+<p class="Note"><strong>Note:</strong> If using the <code>[[Reference:Sky Sphere|sky_sphere]]</code> object, which does not support the <code>finish</code> keyword, instead of a <code>[[Reference:Sphere|sphere]]</code> object that does, you will need define a <code>[[Reference:Default Directive|#default]]</code> finish in order to affect it's finish properties.</p>
 <p>For example:</p>
@@ Line 824: / Line 824: @@
 </table>
-<p>You can strongly affect things with an object's <!--<linkto "Finish">finishes</linkto>--->[[Documentation:Reference Section 5.1#Finish|finish]] attributes. In fact that is the most important thing about radiosity. Normal objects should have an <code>emission 0</code> (the default) finish. Objects with an emission setting greater than zero actually act as light sources in radiosity scenes. Remember that the default finish values used until now were <code>diffuse 0.65</code> and <code>emission 0</code>.</p>
+<p>You can strongly affect things with an object's [[Reference:Finish|finish]] attributes. In fact that is the most important thing about radiosity. Normal objects should have an <code>emission 0</code> (the default) finish. Objects with an emission setting greater than zero actually act as light sources in radiosity scenes. Remember that the default finish values used until now were <code>diffuse 0.65</code> and <code>emission 0</code>.</p>
 <table class="matte" width="700px" cellpadding="0" cellspacing="10px">
@@ Line 1,403: / Line 1,403: @@
 {{#indexentry:Normals and Radiosity}}
 ====Normals and Radiosity====
-<p>When using a <!--<linkto "Normal">normal statement</linkto>--->[[Documentation:Reference Section 3.2#Normal and Radiosity|normal]]  statement in combination with radiosity lighting, you will see that the shadowed parts of the objects are totally smooth, no matter how strong the normals are made. The reason is that POV-Ray by default does not take the normal into account when calculating radiosity. You can easily change this by adding <code>normal on</code> to the radiosity block. Be aware that this can slow things down quite a bit and will require more memory, however it usually leads to more realistic results.</p>
+<p>When using a [[Reference:Radiosity#Normal and Radiosity|normal]]  statement in combination with radiosity lighting, you will see that the shadowed parts of the objects are totally smooth, no matter how strong the normals are made. The reason is that POV-Ray by default does not take the normal into account when calculating radiosity. You can easily change this by adding <code>normal on</code> to the radiosity block. Be aware that this can slow things down quite a bit and will require more memory, however it usually leads to more realistic results.</p>
-<p>When using normals you should also remember that they are only faked irregularities and do not generate real geometric disturbances of the surface. A more realistic approach is using an <!--<linkto "Isosurface Object">isosurface</linkto>--->[[Documentation:Reference Section 4#Isosurface|isosurface]] with a pigment function, but this can quickly lead to increased render times.</p>
+<p>When using normals you should also remember that they are only faked irregularities and do not generate real geometric disturbances of the surface. A more realistic approach is using an [[Reference:Isosurface|isosurface]] with a pigment function, but this can quickly lead to increased render times.</p>
 <p>As you can see with this next series of images, the isosurface version does not have the same smooth-like appearance to it's circumference, as compared to the first two images. Notice that it also has a more realistic shadow-line.</p>
@@ Line 1,439: / Line 1,439: @@
 <p>If average to good quality radiosity will work for your scene, then it's probably a good idea to spend the time to find the <em>sweet spot</em> that strikes the best balance between quality and speed.  Especially <code>recursion_limit</code> should be kept as low as possible. Sometimes <code>1</code> is sufficient, if not <code>2</code> or <code>3</code> should often be enough.</p>
-<p>With high quality settings, radiosity data can take quite a lot of memory. Apart from that the other scene data is also used much more intensively than in a conventional scene. Therefore insufficient memory and swapping can slow down things even more. Here's a few [[Documentation:Reference Section 1.3#Radiosity Options|radiosity options]] that might help.</p>
+<p>With high quality settings, radiosity data can take quite a lot of memory. Apart from that the other scene data is also used much more intensively than in a conventional scene. Therefore insufficient memory and swapping can slow down things even more. Here's a few [[Reference :Tracing Options|Radiosity Options|radiosity options]] that might help.</p>
-<p>Finally the scene geometry and textures are important too. Objects not visible in the camera usually only increase parsing time and memory use, but in a radiosity scene, also objects behind the camera can slow down the rendering process. See the section [[Documentation:Reference Section 3.2#Configuring Radiosity|Configuring Radiosity]] for some helpful hints.</p>
+<p>Finally the scene geometry and textures are important too. Objects not visible in the camera usually only increase parsing time and memory use, but in a radiosity scene, also objects behind the camera can slow down the rendering process. See the section [[Reference:Radiosity#Configuring Radiosity|Configuring Radiosity]] for some helpful hints.</p>
 ===Making Animations===
@@ Line 1,475: / Line 1,475: @@
 ====The Clock Variable: Key To It All====
 <p>POV-Ray supports an automatically declared floating point variable
-identified as <code><!--<linkto "clock">clock</linkto>--->[[Documentation:Reference Section 2.1#Built-in Variables|clock]]</code> (all lower case). This is the key to making
+identified as <code>[[Reference:Numeric Expressions#Built-in Variables|clock]]</code> (all lower case). This is the key to making
 image files that can be automated. In command line operations, the clock
 variable is set using the <code>+k</code> switch. For example, <code>
@@ Line 1,645: / Line 1,645: @@
 ====The Phase Keyword====
 <p>There is another keyword we should know for purposes of animations: the
-<code><!--<linkto "phase">phase</linkto>--->[[Documentation:Reference Section 5.5#Pattern Modifiers|phase]]</code> keyword. The phase keyword can be used on many texture
+<code>[[Reference:Pattern Modifiers#Frequency and Phase|phase]]</code> keyword. The phase keyword can be used on many texture
 elements, especially those that can take a color, pigment, normal or texture
 map. Remember the form that these maps take. For example:</p>