Reference:Finish - Revision history

Maurice: Precision about 40 char limited version number

2021-07-02T20:55:37Z

Precision about 40 char limited version number

Clipka: Fix a typo

2021-07-01T19:51:35Z

Fix a typo

Jholsenback: technical correction

2018-10-01T22:21:40Z

technical correction

Jholsenback: emphasis

2017-09-30T22:37:33Z

emphasis

Jholsenback: link repair

2017-08-13T19:17:32Z

link repair

Jholsenback: update 3.8 changes

2017-07-14T10:39:15Z

update 3.8 changes

Jholsenback: version changes

2017-06-26T10:18:54Z

version changes

Jholsenback: minor syntax diagram changes

2016-12-21T17:10:53Z

minor syntax diagram changes

Jholsenback: replaced current "exponent" narrative

2016-12-21T16:53:59Z

replaced current "exponent" narrative

Jholsenback: suppressed TOC in this file

2016-12-21T15:58:34Z

suppressed TOC in this file

@@ Line 31: / Line 31: @@
 </pre>
-<p class="Note"><strong>Note:</strong> In previous versions identifier names <em>were</em> limited to 40 characters. There has been a {{Change}} removing that restriction.</p>
+<p class="Note"><strong>Note:</strong> In versions prior to 3.6.2, identifier names <em>were</em> limited to 40 characters. There has been a {{Change}} removing that restriction.</p>
 <p>The <em>FINISH_IDENTIFIER</em> is optional but should proceed all other items. Any items after the <em>FINISH_IDENTIFIER</em> modify or override settings given in the <em>FINISH_IDENTIFIER</em>. If no identifier is specified then the items modify the finish values in the current default texture.</p>

@@ Line 61: / Line 61: @@
 <p class="Note"><strong>Note:</strong> For more physical realism a {{Change}} in version 3.8 expands <code>fresnel</code> angle-dependent attenuation use to now include the <code>ambient</code>, <code>diffuse</code>, <code>emission</code>, <code>specular</code> and <code>phong</code> components. The details are as follows:</p>
-<p>When used directly in the <code>finish</code> block the <code>fresnel</code> keyword activates <em>Fresnel</em> effects for all of the <code>ambient</code>, <code>diffuse</code>, <code>emission</code>, <code>specular</code> and <code>phong</code> attributes. At steep viewing and/or light source angles it decreases the brightness of the <code>specular</code> and <code>phong</code> components. At shallow viewing angles and/or light source angles it instead decreases the brightness of the <code>ambient</code>, <code>diffuse</code> and <code>emission</code> components. The <code>fresnel</code> parameter can also be set to an intermediate value, in order to allow for the approximate modelling of anti-reactive coatings.</p>
+<p>When used directly in the <code>finish</code> block the <code>fresnel</code> keyword activates <em>Fresnel</em> effects for all of the <code>ambient</code>, <code>diffuse</code>, <code>emission</code>, <code>specular</code> and <code>phong</code> attributes. At steep viewing and/or light source angles it decreases the brightness of the <code>specular</code> and <code>phong</code> components. At shallow viewing angles and/or light source angles it instead decreases the brightness of the <code>ambient</code>, <code>diffuse</code> and <code>emission</code> components. The <code>fresnel</code> parameter can also be set to an intermediate value, in order to allow for the approximate modelling of anti-reflective coatings.</p>
 <p>In the following example the <code>diffuse</code>, <code>phong</code> and <code>specular</code> syntax, which is normally used to specify the effective <em>bi-hemispheric albedo</em> of that respective component, does not work as advertised when finish-level <code>fresnel</code> is set to non-zero. Instead, <code>diffuse</code> will specify the <em>albedo</em> that the object would exhibit if it had a refractive index of 1, while <code>phong</code> and <code>specular</code> will specify the <em>albedo</em> that the object would exhibit if it had an infinitely large refractive index. As a result, while you would normally want to choose parameters such that <em>D_Value + P_Value + S_Value &lt;= 1</em>. With finish-level <code>fresnel</code> set to a non-zero value you would want to choose parameters such that <em>D_Value &lt;= 1</em> and <em>P_Value + S_Value &lt;= 1</em>. For optimal realism, you should specify the settings as noted below, and control the brightness of the <code>diffuse</code> component via the layer pigment.</p>

@@ Line 118: / Line 118: @@
 <p class="Note"><strong>Note:</strong> Specular reflected indirect illumination like a flashlight shining in a mirror cannot modeled by either ambient light or radiosity. Use [[Reference:Photons|photons]] instead.</p>
-<p>There has been an important {{Change}} in version 3.8 regarding the default <code>ambient</code> setting. When <code>[[Reference:Version Directive|#version]]</code> is set as <em>either</em> the <em>VERY</em> first statement of the scene file or via [[Reference:Scene Parsing Options#Language Version|command-line option]] and the version is 3.8 or greater the default setting is now <code>ambient 0</code> as opposed to the <code>ambient 0.1</code> value used in previous versions.</p>
+<p>In version 3.8 there has been a {{Change}} to the <code>ambient</code> default setting. The default setting is now <code>ambient 0</code> as opposed to the <code>ambient 0.1</code> value used in previous versions. Requires <code>#version 3.8;</code> or equivalent INI setting or command-line option. See also: [[Reference:Version Directive|Version Directive]].</p>
 ==Emission==

@@ Line 118: / Line 118: @@
 <p class="Note"><strong>Note:</strong> Specular reflected indirect illumination like a flashlight shining in a mirror cannot modeled by either ambient light or radiosity. Use [[Reference:Photons|photons]] instead.</p>
-<p>There has been an important {{Change}} in version 3.8 regarding the default <code>ambient</code> setting. When <code>[[Reference:Version Directive|#version]]</code> is set as <em>either</em> the first statement of the scene file or via [[Reference:Scene Parsing Options#Language Version|command-line option]] and the version is 3.8 or greater the default setting is now <code>ambient 0</code> as opposed to the <code>ambient 0.1</code> value used in previous versions.</p>
+<p>There has been an important {{Change}} in version 3.8 regarding the default <code>ambient</code> setting. When <code>[[Reference:Version Directive|#version]]</code> is set as <em>either</em> the <em>VERY</em> first statement of the scene file or via [[Reference:Scene Parsing Options#Language Version|command-line option]] and the version is 3.8 or greater the default setting is now <code>ambient 0</code> as opposed to the <code>ambient 0.1</code> value used in previous versions.</p>
 ==Emission==

@@ Line 118: / Line 118: @@
 <p class="Note"><strong>Note:</strong> Specular reflected indirect illumination like a flashlight shining in a mirror cannot modeled by either ambient light or radiosity. Use [[Reference:Photons|photons]] instead.</p>
-<p>There has been an important {{Change}} in version 3.8 regarding the default <code>ambient</code> setting. When <code>[[Reference:Version Directive|#version]]</code> is set as <em>either</em> the first statement of the scene file or via [[Reference:Scene Parsing_Options#Language Version|command-line option]] and the version is 3.8 or greater the default setting is now <code>ambient 0</code> as opposed to the <code>ambient 0.1</code> value used in previous versions.</p>
+<p>There has been an important {{Change}} in version 3.8 regarding the default <code>ambient</code> setting. When <code>[[Reference:Version Directive|#version]]</code> is set as <em>either</em> the first statement of the scene file or via [[Reference:Scene Parsing Options#Language Version|command-line option]] and the version is 3.8 or greater the default setting is now <code>ambient 0</code> as opposed to the <code>ambient 0.1</code> value used in previous versions.</p>
 ==Emission==

← Older revision		Revision as of 10:39, 14 July 2017
Line 117:		Line 117:

	<p class="Note"><strong>Note:</strong> Specular reflected indirect illumination like a flashlight shining in a mirror cannot modeled by either ambient light or radiosity. Use [[Reference:Photons\|photons]] instead.</p>		<p class="Note"><strong>Note:</strong> Specular reflected indirect illumination like a flashlight shining in a mirror cannot modeled by either ambient light or radiosity. Use [[Reference:Photons\|photons]] instead.</p>
		+
		+	<p>There has been an important {{Change}} in version 3.8 regarding the default <code>ambient</code> setting. When <code>[[Reference:Version Directive\|#version]]</code> is set as <em>either</em> the first statement of the scene file or via [[Reference:Scene Parsing_Options#Language Version\|command-line option]] and the version is 3.8 or greater the default setting is now <code>ambient 0</code> as opposed to the <code>ambient 0.1</code> value used in previous versions.</p>

	==Emission==		==Emission==

@@ Line 59: / Line 59: @@
 <p>Where <em>IDENTIFIER</em> is the name of the identifier and <em>FINISH</em> is any valid <code>finish</code> statement. See [[Reference:Declare and Local Directives#declare vs. local|#declare vs. #local]] for information on identifier scope.</p>
-<p class="Note"><strong>Note:</strong> For more physical realism a {{Change}} in version 3.7.1 expands <code>fresnel</code> angle-dependent attenuation use to now include the <code>ambient</code>, <code>diffuse</code>, <code>emission</code>, <code>specular</code> and <code>phong</code> components. The details are as follows:</p>
+<p class="Note"><strong>Note:</strong> For more physical realism a {{Change}} in version 3.8 expands <code>fresnel</code> angle-dependent attenuation use to now include the <code>ambient</code>, <code>diffuse</code>, <code>emission</code>, <code>specular</code> and <code>phong</code> components. The details are as follows:</p>
 <p>When used directly in the <code>finish</code> block the <code>fresnel</code> keyword activates <em>Fresnel</em> effects for all of the <code>ambient</code>, <code>diffuse</code>, <code>emission</code>, <code>specular</code> and <code>phong</code> attributes. At steep viewing and/or light source angles it decreases the brightness of the <code>specular</code> and <code>phong</code> components. At shallow viewing angles and/or light source angles it instead decreases the brightness of the <code>ambient</code>, <code>diffuse</code> and <code>emission</code> components. The <code>fresnel</code> parameter can also be set to an intermediate value, in order to allow for the approximate modelling of anti-reactive coatings.</p>
@@ Line 87: / Line 87: @@
 <p>Radiosity-based illumination currently does not account for the <em>Fresnel</em> effect on incoming light, regardless of the finish-level <code>fresnel</code> parameter.</p>
-<p>{{New}} in version 3.7.1 you can now specify <code>use_alpha</code> in the <code>finish</code> block. If set to <code>off</code>, the default and also the old behavior, then <code>pigment</code> <em>filter</em> and <em>transmit</em> only hide the surface's <code>diffuse</code>, <code>ambient</code> and <code>emission</code> components. If set to <code>on</code> then <code>pigment</code> <em>filter</em> and <em>transmit</em> also hide the surface's highlights and <code>specular</code> reflection.</p>
+<p>{{New}} in version 3.8 you can now specify <code>use_alpha</code> in the <code>finish</code> block. If set to <code>off</code>, the default and also the old behavior, then <code>pigment</code> <em>filter</em> and <em>transmit</em> only hide the surface's <code>diffuse</code>, <code>ambient</code> and <code>emission</code> components. If set to <code>on</code> then <code>pigment</code> <em>filter</em> and <em>transmit</em> also hide the surface's highlights and <code>specular</code> reflection.</p>
 ==Ambient==

@@ Line 12: / Line 12: @@
    finish { [FINISH_IDENTIFIER] [FINISH_ITEMS...] }
 FINISH_ITEMS:
    ambient COLOR | diffuse [albedo] Amount [, Amount] |
    emission COLOR | brilliance Amount | phong [albedo] Amount | phong_size Amount |
@@ Line 20: / Line 21: @@
    subsurface { translucency COLOR } |
    irid { Irid_Amount [IRID_ITEMS...] |
    use_alpha BOOL
+   }

@@ Line 349: / Line 349: @@
 {{#indexentry:reflection, exponent}}
 <p><strong>exponent</strong><br>
-POV-Ray uses a limited light model that cannot distinguish between objects which are simply
+This property predates the introduction of <em>proper</em> gamma handling. People found that it was difficult to model partially reflective surfaces in a realistic way, as middle and lower brightness objects typically looked too bright when reflected. As a means to work around the phenomenon the optional <code>exponent</code> keyword was added, producing non-linear reflection intensities. The default value of 1.0 produces a linear curve. Lower values darken middle and low intensities and keep high intensity reflections bright. While this feature may still be used for artistic effects, it is strongly discouraged for renders aiming at realism. The original phenomenon is well understood by now, and using <code>assumed_gamma 1.0</code> as recommended will avoid it entirely.
 </p>
 {{#indexentry:variable reflection}}
 <p><strong>Variable reflection</strong><br>
-Many materials, such as water, ceramic glaze, and linoleum are more reflective when viewed at shallow angles.
+Many materials, such as water, ceramic glaze, and linoleum are more reflective when viewed at shallow angles. This can be simulated by also specifying a minimum reflection in the <code>reflection {...}</code> statement.
 <br>For example:
 </p>

@@ Line 1: / Line 1: @@
 [[Category:Textures]]
 [[Category:Object Modifiers]]
 {{#indexentry:finish, keyword}}
 {{#indexentry:keyword, finish}}