Reference:Color Map - Revision history

Jholsenback: corrections

2017-07-24T10:45:40Z

corrections

Jholsenback: clarification and clean up

2017-07-23T14:02:22Z

clarification and clean up

Jholsenback: version changes

2017-06-26T10:16:04Z

version changes

Jholsenback: link repair

2016-12-11T16:47:34Z

link repair

Jholsenback: documenting map entry upper restriction change

2016-11-20T23:18:21Z

documenting map entry upper restriction change

Jholsenback: cleanup and blend mode / gamma additions)

2016-11-19T14:16:47Z

cleanup and blend mode / gamma additions)

Jholsenback: 1 revision: Reference Migration Initial Load

2012-03-15T19:05:16Z

1 revision: Reference Migration Initial Load

Jholsenback: 1 revision: Initial Load (TF)

2012-03-11T22:27:48Z

1 revision: Initial Load (TF)

New page

{{#indexentry:pigments, color maps}}
{{#indexentry:color_map, colour_map}}
Most of the color patterns do not use abrupt color changes of just two or three colors like those in the brick, checker or hexagon patterns. They instead use smooth transitions of many colors that gradually change from one point to the next. The colors are defined in a pigment modifier called a <code>color_map</code> that describes how the pattern blends from one color to the next.
Each of the various pattern types available is in fact a mathematical function that takes any x, y, z location and turns it into a number between 0.0 and 1.0 inclusive. That number is used to specify what mix of colors to use from the color map.
The syntax for <code> color_map</code> is as follows:
<pre>
COLOR_MAP:
color_map { COLOR_MAP_BODY } | colour_map { COLOR_MAP_BODY }
COLOR_MAP_BODY:
COLOR_MAP_IDENTIFIER | COLOR_MAP_ENTRY...
COLOR_MAP_ENTRY:
[ Value COLOR ] |
[ Value_1, Value_2 color COLOR_1 color COLOR_2 ]
</pre>
Where each <code>Value_n</code> is a float values between 0.0 and 1.0 inclusive and each COLOR_n, is color specifications. 
Note: The <code>[]</code> brackets are part of the actual 
COLOR_MAP_ENTRY. They are not notational symbols denoting optional parts. The brackets surround each entry in the color map.
 There may be from 2 to 256 entries in the map. The alternate spelling <code>colour_map</code> may be used.
Here is an example:
<pre>
sphere {
<0,1,2>, 2
pigment {
gradient x //this is the PATTERN_TYPE
color_map {
[0.1 color Red]
[0.3 color Yellow]
[0.6 color Blue]
[0.6 color Green]
[0.8 color Cyan]
}
}
}
</pre>
The pattern function <code>gradient x</code> is evaluated and the result is a value from 0.0 to 1.0. If the value is less than the first entry (in this case 0.1) then the first color (red) is used. Values from 0.1 to 0.3 use a blend of red and yellow using linear interpolation of the two colors. Similarly values from 0.3 to 0.6 blend from yellow to blue.
The 3rd and 4th entries both have values of 0.6. This causes an immediate abrupt shift of color from blue to green. Specifically a value that is less than 0.6 will be blue but exactly equal to 0.6 will be green. Moving along, values from 0.6 to 0.8 will be a blend of green and cyan. Finally any value greater than or equal to 0.8 will be cyan.
If you want areas of unchanging color you simply specify the same color for two adjacent entries. For example:
<pre>
color_map {
[0.1 color Red]
[0.3 color Yellow]
[0.6 color Yellow]
[0.8 color Green]
}
</pre>
In this case any value from 0.3 to 0.6 will be pure yellow.
The first syntax version of COLOR_MAP_ENTRY with one float and one color is the current standard. The other double entry version is obsolete and should be avoided. The previous example would look as follows using the old syntax.
<pre>
color_map {
[0.0 0.1 color Red color Red]
[0.1 0.3 color Red color Yellow]
[0.3 0.6 color Yellow color Yellow]
[0.6.0.8 color Yellow color Green]
[0.8 1.0 color Green color Green]
}
</pre>
You may use <code>color_map</code> with any patterns except <code>brick</code>, <code>checker</code>, <code>hexagon</code>, <code>object</code> and <code>image_map</code>. You may declare and use <code>color_map</code> identifiers. For example:
<pre>
#declare Rainbow_Colors=
color_map {
[0.0 color Magenta]
[0.33 color Yellow]
[0.67 color Cyan]
[1.0 color Magenta]
}
object {
My_Object
pigment {
gradient x
color_map { Rainbow_Colors }
}
}
</pre>

@@ Line 6: / Line 6: @@
 <p>Each of the various pattern types available is in fact a mathematical function that takes any x, y, z location and turns it into a number between 0.0 and 1.0 inclusive. That number is used to specify what mix of colors to use from the color map.</p>
 <p>The syntax for <code> color_map</code> is as follows:</p>
 <pre>
 COLOR_MAP:
-   color_map { [blend_mode [BLEND_MODE]] [blend_gamma [FLOAT]] COLOR_MAP_BODY } |
+   color_map { COLOR_MAP_BODY } |
-   colour_map { [blend_mode [BLEND_MODE]] [blend_gamma [FLOAT]] COLOR_MAP_BODY }
+   colour_map { COLOR_MAP_BODY }
 BLEND_MODE:
-   [0] | 1 | 2 | 3
+| 1 | 2 | 3
 COLOR_MAP_ENTRY:
    [ Value COLOR ] |

@@ Line 8: / Line 8: @@
 <pre>
 COLOR_MAP:
-   color_map { COLOR_MAP_BODY } | color_map { COLOR_MAP_BODY }
+   color_map { [blend_mode [BLEND_MODE]] [blend_gamma [FLOAT]] COLOR_MAP_BODY } |
-COLOR_MAP_BODY:
+   colour_map { [blend_mode [BLEND_MODE]] [blend_gamma [FLOAT]] COLOR_MAP_BODY }
 BLEND_MODE:
    [0] | 1 | 2 | 3
 COLOR_MAP_ENTRY:
    [ Value COLOR ] |
@@ Line 19: / Line 20: @@
 <p>Where each <em><code>Value_n</code></em> is a float values between 0.0 and 1.0 inclusive and each <em>COLOR_n</em>, are color specifications.</p>
 <p class="Note"><strong>Note:</strong> The <code>[]</code> brackets that are part of the actual <em>COLOR_MAP_ENTRY</em> should not confused with the symbols denoting optional syntax.</p>
 <p>In <em>previous</em> versions there <em>had</em> to be from 2 to 256 entries in the map. A {{Change}} in version 3.8 has removed the upper restriction. The alternate spelling <code>colour_map</code> can also be used.</p>
-<p>Here's an example:</p>
+<p>Here's a simple example:</p>
 <pre>
 sphere {
@@ Line 81: / Line 90: @@
 </pre>
-<p>The possible values for <code>blend_mode</code> and their descriptions are as follows:</p>
+<p>See also: [[Reference:Pigment Map|Pigment Maps]].</p>

@@ Line 3: / Line 3: @@
 {{#indexentry:blend_map}}
 {{#indexentry:blend_gamma}}
-<p>Most of the color patterns do not use abrupt color changes of just two or three colors like those in the <code>brick</code>, <code>checker</code> or <code>hexagon</code> patterns. They instead use smooth transitions of many colors that gradually change from one point to the next. The colors are defined in a pigment modifier called a <code>color_map</code> that describes how the pattern blends from one color to the next. {{New}} in version 3.7.1 non-linear color map interpolation support has been added.</p>
+<p>Most of the color patterns do not use abrupt color changes of just two or three colors like those in the <code>brick</code>, <code>checker</code> or <code>hexagon</code> patterns. They instead use smooth transitions of many colors that gradually change from one point to the next. The colors are defined in a pigment modifier called a <code>color_map</code> that describes how the pattern blends from one color to the next. {{New}} in version 3.8 non-linear color map interpolation support has been added.</p>
 <p>Each of the various pattern types available is in fact a mathematical function that takes any x, y, z location and turns it into a number between 0.0 and 1.0 inclusive. That number is used to specify what mix of colors to use from the color map.</p>
 <p>The syntax for <code> color_map</code> is as follows:</p>
@@ Line 22: / Line 22: @@
 <p class="Note"><strong>Note:</strong> The <code>[]</code> brackets that are part of the actual <em>COLOR_MAP_ENTRY</em> should not confused with the symbols denoting optional syntax.</p>
-<p>In <em>previous</em> versions there <em>had</em> to be from 2 to 256 entries in the map. A {{Change}} in version 3.7.1 has removed the upper restriction. The alternate spelling <code>colour_map</code> can also be used.</p>
+<p>In <em>previous</em> versions there <em>had</em> to be from 2 to 256 entries in the map. A {{Change}} in version 3.8 has removed the upper restriction. The alternate spelling <code>colour_map</code> can also be used.</p>
 <p>Here's an example:</p>
 <pre>

← Older revision		Revision as of 16:47, 11 December 2016
Line 89:		Line 89:
	</ul>		</ul>

−	<p>[[Reference:~~Pigment_Map~~\|Pigment Maps]] also support the {{New}} non-linear interpolation scheme.</p>	+	<p>[[Reference:Pigment Map\|Pigment Maps]] also support the {{New}} non-linear interpolation scheme.</p>

@@ Line 22: / Line 22: @@
 <p class="Note"><strong>Note:</strong> The <code>[]</code> brackets that are part of the actual <em>COLOR_MAP_ENTRY</em> should not confused with the symbols denoting optional syntax.</p>
-<p>There may be from 2 to 256 entries in the map. The alternate spelling <code>colour_map</code> can also be used.</p>
+<p>In <em>previous</em> versions there <em>had</em> to be from 2 to 256 entries in the map. A {{Change}} in version 3.7.1 has removed the upper restriction. The alternate spelling <code>colour_map</code> can also be used.</p>
 <p>Here's an example:</p>
 <pre>

@@ Line 1: / Line 1: @@
 {{#indexentry:pigments, color maps}}
 {{#indexentry:color_map, colour_map}}
-<p>Most of the color patterns do not use abrupt color changes of just two or three colors like those in the brick, checker or hexagon patterns. They instead use smooth transitions of many colors that gradually change from one point to the next. The colors are defined in a pigment modifier called a <code>color_map</code> that describes how the pattern blends from one color to the next.</p>
+{{#indexentry:blend_map}}
 <p>Each of the various pattern types available is in fact a mathematical function that takes any x, y, z location and turns it into a number between 0.0 and 1.0 inclusive. That number is used to specify what mix of colors to use from the color map.</p>
 <p>The syntax for <code> color_map</code> is as follows:</p>
 <pre>
 COLOR_MAP:
-   color_map { COLOR_MAP_BODY } | colour_map { COLOR_MAP_BODY }
+   color_map { COLOR_MAP_BODY } | color_map { COLOR_MAP_BODY }
 COLOR_MAP_BODY:
-   COLOR_MAP_IDENTIFIER | COLOR_MAP_ENTRY...
+   COLOR_MAP_IDENTIFIER | [blend_mode [BLEND_MODE]] [blend_gamma [FLOAT]] | COLOR_MAP_ENTRY...
 COLOR_MAP_ENTRY:
    [ Value COLOR ] |
    [ Value_1, Value_2 color COLOR_1 color COLOR_2 ]
 </pre>
-<p>Where each <em><code>Value_n</code></em> is a float values between 0.0 and 1.0 inclusive and each <em>COLOR_n</em>, is color specifications. </p>
-<p class="Note"><strong>Note:</strong> The <code>[]</code> brackets are part of the actual <em>
+<p>Where each <em><code>Value_n</code></em> is a float values between 0.0 and 1.0 inclusive and each <em>COLOR_n</em>, are color specifications.</p>
-COLOR_MAP_ENTRY</em>. They are not notational symbols denoting optional parts. The brackets surround each entry in the color map.</p>
-<p> There may be from 2 to 256 entries in the map. The alternate spelling <code>colour_map</code> may be used.</p>
+<p class="Note"><strong>Note:</strong> The <code>[]</code> brackets that are part of the actual <em>COLOR_MAP_ENTRY</em> should not confused with the symbols denoting optional syntax.</p>
-<p>Here is an example:</p>
 <pre>
 sphere {
@@ Line 35: / Line 41: @@
 <p>The pattern function <code>gradient x</code> is evaluated and the result is a value from 0.0 to 1.0. If the value is less than the first entry (in this case 0.1) then the first color (red) is used. Values from 0.1 to 0.3 use a blend of red and yellow using linear interpolation of the two colors. Similarly values from 0.3 to 0.6 blend from yellow to blue.</p>
 <p>The 3rd and 4th entries both have values of 0.6. This causes an immediate abrupt shift of color from blue to green. Specifically a value that is less than 0.6 will be blue but exactly equal to 0.6 will be green. Moving along, values from 0.6 to 0.8 will be a blend of green and cyan. Finally any value greater than or equal to 0.8 will be cyan.</p>
-<p>If you want areas of unchanging color you simply specify the same color for two adjacent entries. For example:</p>
+<p>If you want areas of unchanging color you simply specify the same color for two adjacent entries.</p>
 <pre>
 color_map {
@@ Line 55: / Line 62: @@
+   }
 </pre>
-<p>You may use <code>color_map</code> with any patterns except <code>brick</code>, <code>checker</code>, <code>hexagon</code>, <code>object</code> and <code>image_map</code>. You may declare and use <code>color_map</code> identifiers. For example:</p>
+<p>You may use <code>color_map</code> with any patterns except <code>brick</code>, <code>checker</code>, <code>hexagon</code>, <code>object</code> and <code>image_map</code>. You may also declare and use <code>color_map</code> identifiers.</p>
 <pre>
 #declare Rainbow_Colors=
@@ Line 72: / Line 80: @@
+   }
 </pre>

← Older revision	Revision as of 19:05, 15 March 2012
(No difference)