Documentation Talk:Reference Section 1 - Revision history

Jholsenback: follow up

2010-11-13T11:18:47Z

follow up

Le Forgeron: Adding +STP/Frame_Step, Querying the MS-DOS limitation

2010-11-10T22:05:37Z

Adding +STP/Frame_Step, Querying the MS-DOS limitation

Jholsenback: follow up

2010-05-28T03:30:59Z

follow up

Show changes

Jholsenback at 03:04, 28 May 2010

2010-05-28T03:04:23Z

Newacct at 18:53, 27 May 2010

2010-05-27T18:53:28Z

Jholsenback: created talk page

2009-10-11T12:30:50Z

created talk page

New page

===Command-line Options===
The reference section describes all command line switches and INI file
keywords that are used to set the options of POV-Ray. It is supposed to be
used as a reference for looking up things. It does not contain detailed
explanations on how scenes are written or how POV-Ray is used. It just
explains all features, their syntax, applications, limits, drawbacks,
etc.

Options may be specified by switches
or INI-style options. Almost all INI-style options have equivalent <code>
+</code>/ <code>-</code> switches and most switches have equivalent INI-style
option. The following sections give a detailed description of each POV-Ray
option. It includes both the INI-style settings and the <code> +</code>/
<code>-</code> switches.

The notation and terminology used is described in the tables below.

<table width="100%">
<tr>
<td width="30%"><code>Keyword=</code>bool</td>

<td width="70%">Turn <code>Keyword</code> on if bool equals <code>true</code>, <code>
yes</code>, <code>on</code> or <code>1</code> and Turn it off if it is any
other value.</td>
</tr>

<tr>
<td><code>Keyword=true</code></td>

<td>Do this option if <code>true</code>, <code>yes</code>, <code> on</code>
or <code>1</code> is specified.</td>
</tr>

<tr>
<td><code>Keyword=false</code></td>

<td>Do this option if <code>false</code>, <code>no</code>, <code>
off</code> or <code>0</code> is specified.</td>
</tr>

<tr>
<td><code>Keyword=</code>filename</td>

<td>Set <code>Keyword</code> to filename where filename is any valid file
name.
Note: some options prohibit the use of any of the above <code>
true</code> or <code>false</code> values as a file name. They are noted in
later sections.</td>
</tr>

<tr>
<td>n</td>

<td>Any integer such as in <code>+W320</code></td>
</tr>

<tr>
<td>n.n</td>

<td>Any float such as in <code>Clock=3.45</code></td>
</tr>

<tr>
<td>0.n</td>

<td>Any float < 1.0 even if it has no leading 0</td>
</tr>

<tr>
<td>s</td>

<td>Any string of text</td>
</tr>

<tr>
<td>x or y</td>

<td>Any single character</td>
</tr>

<tr>
<td>path</td>

<td>Any directory name, drive optional, no final path separator
("\" or "/", depending on the operating system)</td>
</tr>
</table>

Unless otherwise specifically noted, you may assume that either a plus or
minus sign before a switch will produce the same results.

===Animation Options===


Internal animation loop, automatic output file name numbering and the
ability to shell out to the operating system to external utilities which can
assemble individual frames into an animation, greatly improved the animation capability.
The internal animation loop is simple yet flexible. You may still use external programs or batch files to
create animations without the internal loop.

===External Animation Loop===


<table width="100%">
<tr>
<td width="30%"><code>Clock=</code>n.n</td>

<td width="70%">Sets <code>[[Documentation:Reference Section 2.1#Built-in Variables|clock]]</code> float identifier to n.n</td>
</tr>

<tr>
<td><code>+K</code>n.n</td>

<td>Same as <code>Clock=</code>n.n</td>
</tr>
</table>

The <code>Clock=</code>n.n option or the <code>
+K</code>n.n switch may be used to pass a single float value to the
program for basic animation. The value is stored in the float identifier
<code>clock</code>. If an object had a <code>rotate <0,clock,0></code>
attached then you could rotate the object by different amounts over different
frames by setting <code> +K10.0</code>,<code>+K20.0</code>... etc. on
successive renderings. It is up to the user to repeatedly invoke POV-Ray with
a different <code> Clock</code> value and a different <code>
Output_File_Name</code> for each frame.

===Internal Animation Loop===

<table width="100%">
<tr>
<td width="30%"><code>Initial_Frame=</code>n</td>

<td width="70%">Sets initial frame number to n</td>
</tr>

<tr>
<td><code>Final_Frame=</code>n</td>

<td>Sets final frame number to n</td>
</tr>

<tr>
<td><code>Initial_Clock=</code>n.n</td>

<td>Sets initial clock value to n.n</td>
</tr>

<tr>
<td><code>Final_Clock=</code>n.n</td>

<td>Sets final clock value to n.n</td>
</tr>

<tr>
<td><code>+KFI</code>n</td>

<td>Same as <code>Initial_Frame=</code>n</td>
</tr>

<tr>
<td><code>+KFF</code>n</td>

<td>Same as <code>Final_Frame=</code>n</td>
</tr>

<tr>
<td><code>+KI</code>n.n</td>

<td>Same as <code>Initial_Clock=</code>n.n</td>
</tr>

<tr>
<td><code>+KF</code>n.n</td>

<td>Same as <code>Final_Clock=</code>n.n</td>
</tr>
</table>

The internal animation loop relieves the user of the
task of generating complicated sets of batch files to invoke POV-Ray multiple
times with different settings. While the multitude of options may look
intimidating, the clever set of default values means that you will probably
only need to specify the <code>Final_Frame</code>=n or the
<code>+KFF</code>n option to specify the number of frames. All other
values may remain at their defaults.

Any <code>Final_Frame</code> setting other than -1 will trigger
POV-Ray's internal animation loop. For example <code>
Final_Frame=10</code> or <code>+KFF10</code> causes POV-Ray to render your
scene 10 times. If you specified <code>[[Documentation:Reference Section 1.1#Output File Name|Output_File_Name]]=file.tga</code>
then each frame would be output as <code>file01.tga</code>, <code>file02.tga</code>,
<code>file03.tga</code> etc. The number of zero-padded digits in the file name
depends upon the final frame number. For example <code>+KFF100</code> would
generate <code>file001.tga</code> through <code>file100.tga</code>. The frame
number may encroach upon the file name. On MS-DOS with an eight character limit,
<code>myscene.pov</code> would render to <code>mysce001.tga</code> through
<code>mysce100.tga</code>.

The default <code>Initial_Frame=1</code> will probably never have to be
changed. You would only change it if you were assembling a long animation
sequence in pieces. One scene might run from frame 1 to 50 and the next from
51 to 100. The <code>Initial_Frame</code>=n or <code>
+KFI</code>n option is for this purpose.
Note: if you wish to render a subset of frames such as 30 through 40 out
of a 1 to 100 animation, you should not change <code>Initial_Frame</code> or
<code>Final_Frame</code>. Instead you should use the subset commands
described in section "[[Documentation:Reference Section 1#Subsets of Animation Frames|Subsets of Animation Frames]]".

Unlike some animation packages, the action in POV-Ray animated scenes does
not depend upon the integer frame numbers. Rather you should design your
scenes based upon the float identifier <code>[[Documentation:Reference Section 2.1#Built-in Variables|clock]]</code>. By default, the
clock value is 0.0 for the initial frame and 1.0 for the final frame. All
other frames are interpolated between these values. For example if your
object is supposed to rotate one full turn over the course of the animation,
you could specify <code>rotate 360*clock*y</code>. Then as clock runs from
0.0 to 1.0, the object rotates about the y-axis from 0 to 360 degrees.

The major advantage of this system is that you can render a 10 frame
animation or a 100 frame or 500 frame or 329 frame animation yet you still
get one full 360 degree rotation. Test renders of a few frames work exactly
like final renders of many frames.

In effect you define the motion over a continuous float valued parameter
(the clock) and you take discrete samples at some fixed intervals (the
frames). If you take a movie or video tape of a real scene it works the same
way. An object's actual motion depends only on time. It does not depend
on the frame rate of your camera.

Many users have already created scenes for POV-Ray 2 that expect clock
values over a range other than the default 0.0 to 1.0. For this reason we
provide the <code>Initial_Clock</code>=n.n
or <code>+KI</code>n.n and <code>Final_Clock</code>=n.n
or <code>+KF</code>n.n options. For example to run the clock from 25.0 to
75.0 you would specify <code>Initial_Clock=25.0</code> and <code>Final_Clock=75.0</code>.
Then the clock would be set to 25.0 for the initial frame and 75.0 for the final frame.
In-between frames would have clock values interpolated from 25.0 through 75.0 proportionally.

Users who are accustomed to using frame numbers rather than clock values
could specify <code> Initial_Clock=1.0</code> and <code>Final_Clock=10.0</code>
and <code>Frame_Final=10</code> for a 10 frame animation.

For new scenes, we recommend you do not change the <code>
Initial_Clock</code> or <code> Final_Clock</code> from their default 0.0 to
1.0 values. If you want the clock to vary over a different range than the
default 0.0 to 1.0, we recommend you handle this inside your scene file as
follows...
<pre>
#declare Start = 25.0;
#declare End = 75.0;
#declare My_Clock = Start+(End-Start)*clock;
</pre>

Then use <code>My_Clock</code> in the scene description. This keeps the
critical values 25.0 and 75.0 in your .pov file.
Note: more details concerning the inner workings of the animation loop
are in the section on shell-out operating system commands in section
"[[Documentation:Reference Section 1.2#Shell-out to Operating System|Shell-out to Operating System]]".

===Subsets of Animation Frames===


<table width="100%">
<tr>
<td width="30%"><code>Subset_Start_Frame=</code>n

<td width="70%">Set subset starting frame to n</td>
</tr>

<tr>
<td><code>Subset_Start_Frame=</code>0.n</td>

<td>Set subset starting frame to n percent</td>
</tr>

<tr>
<td><code>Subset_End_Frame=</code>n

<td>Set subset ending frame to n</td>
</tr>

<tr>
<td><code>Subset_End_Frame=</code>0.n</td>

<td>Set subset ending frame to n percent</td>
</tr>

<tr>
<td><code>+SF</code>0.n

<td>Same as <code>Subset_Start_Frame</code></td>
</tr>

<tr>
<td><code>+EF</code>0.n

<td>Same as <code>Subset_End_Frame</code></td>
</tr>
</table>

When creating a long animation, it may be handy to render only a portion
of the animation to see what it looks like. Suppose you have 100 frames but
only want to render frames 30 through 40. If you set <code>Initial_Frame=30</code>
and <code>Final_Frame=40</code> then the clock would vary from 0.0 to 1.0 from
frames 30 through 40 rather than 0.30 through 0.40 as it should. Therefore
you should leave <code> Initial_Frame=1</code> and <code>Final_Frame=100</code>
and use <code>Subset_Start_Frame=30</code> and <code>Subset_End_Frame=40</code>
to selectively render part of the scene. POV-Ray will then properly compute the
clock values.

Usually you will specify the subset using the actual integer frame numbers
however an alternate form of the subset commands takes a float value in the
range 0.0 <=n.nnn <=1.0 which is interpreted as a fraction of
the whole animation. For example, <code> Subset_Start_Frame=0.333</code> and
<code>Subset_End_Frame=0.667</code> would render the middle 1/3rd of a
sequence regardless of the number of frames.
===Cyclic Animation===


<table width="100%">
<tr>
<td width="30%"><code>Cyclic_Animation=</code>bool

<td width="70%">Turn cyclic animation on/off</td>
</tr>

<tr>
<td><code>+KC</code>

<td>Turn cyclic animation on</td>
</tr>

<tr>
<td><code>-KC</code>

<td>Turn cyclic animation off</td>
</tr>
</table>

Many computer animation sequences are designed to be run in a continuous
loop. Suppose you have an object that rotates exactly 360 degrees over the
course of your animation and you did <code>rotate 360*clock*y</code> to do
so. Both the first and last frames would be identical. Upon playback there
would be a brief one frame jerkiness. To eliminate this problem you need to
adjust the clock so that the last frame does not match the first. For example
a ten frame cyclic animation should not use clock 0.0 to 1.0. It should run
from 0.0 to 0.9 in 0.1 increments. However if you change to 20 frames it
should run from 0.0 to 0.95 in 0.05 increments. This complicates things
because you would have to change the final clock value every time you changed
<code>Final_Frame</code>. Setting <code>Cyclic_Animation=on</code> or using
<code>+KC</code> will cause POV-Ray to automatically adjust the final clock
value for cyclic animation regardless of how many total frames. The default
value for this setting is off.

===Field Rendering===


<table width="100%">
<tr>
<td width="30%"><code>Field_Render=</code>bool

<td width="70%">Turn field rendering on/off</td>
</tr>

<tr>
<td><code>Odd_Field=</code>bool

<td>Set odd field flag</td>
</tr>

<tr>
<td><code>+UF</code>

<td>Turn field rendering on</td>
</tr>

<tr>
<td><code>-UF</code>

<td>Turn field rendering off</td>
</tr>

<tr>
<td><code>+UO</code>

<td>Set odd field flag on</td>
</tr>

<tr>
<td><code>-UO</code>

<td>Set odd field flag off</td>
</tr>
</table>

Field rendering is sometimes used for animations when the animation is
being output for television. TVs only display alternate scan lines on each
vertical refresh. When each frame is being displayed the fields are
interlaced to give the impression of a higher resolution image. The even scan
lines make up the even field, and are drawn first (i.e. scan lines 0, 2, 4,
etc.), followed by the odd field, made up of the odd numbered scan lines are
drawn afterwards. If objects in an animation are moving quickly, their
position can change noticeably from one field to the next. As a result, it
may be desirable in these cases to have POV-Ray render alternate fields at
the actual field rate (which is twice the frame rate), rather than rendering
full frames at the normal frame rate. This would save a great deal of time
compared to rendering the entire animation at twice the frame rate, and then
only using half of each frame.

By default, field rendering is not used. Setting <code>
Field_Render=on</code> or using <code> +UF</code> will cause alternate frames
in an animation to be only the even or odd fields of an animation. By
default, the first frame is the even field, followed by the odd field. You
can have POV-Ray render the odd field first by specifying <code>
Odd_Field=on</code>, or by using the <code> +UO</code> switch.

===General Output Options===

===Height and Width of Output===


<table width="100%">
<tr>
<td width="30%"><code>Height=</code>n

<td width="70%">Sets screen height to n pixels</td>
</tr>

<tr>
<td><code>Width=</code>n

<td>Sets screen width to n pixels</td>
</tr>

<tr>
<td><code>+H</code>n

<td>Same as <code>Height=</code>n</td>
</tr>

<tr>
<td><code>+W</code>n

<td>Same as <code>Width=</code>n</td>
</tr>
</table>

These switches set the height and width of the image in pixels. This
specifies the image size for file output. The preview display, if on, will
generally attempt to pick a video mode to accommodate this size but the
display settings do not in any way affect the resulting file output.
===Partial Output Options===


<table width="100%">
<tr>
<td width="30%"><code>Start_Column=</code>n

<td width="70%">Set first column to n pixels</td>
</tr>

<tr>
<td><code>Start_Column=</code>0.n</td>

<td>Set first column to n percent of width</td>
</tr>

<tr>
<td><code>+SC</code>0.n

<td>Same as <code>Start_Column</code></td>
</tr>

<tr>
<td><code>Start_Row=</code>n

<td>Set first row to n pixels</td>
</tr>

<tr>
<td><code>Start_Row=</code>0.n</td>

<td>Set first row to n percent of height</td>
</tr>

<tr>
<td><code>+S</code>n

<td>Same as <code>Start_Row=</code>n</td>
</tr>

<tr>
<td><code>+SR</code>0.n or <code>+S</code>0.n</td>

<td>Same as <code>Start_Row=</code>0.n</td>
</tr>

<tr>
<td><code>End_Column=</code>n

<td>Set last column to n pixels</td>
</tr>

<tr>
<td><code>End_Column=</code>0.n</td>

<td>Set last column to n percent of width</td>
</tr>

<tr>
<td><code>+EC</code>0.n

<td>Same as <code>End_Column</code></td>
</tr>

<tr>
<td><code>End_Row=</code>n

<td>Set last row to n pixels</td>
</tr>

<tr>
<td><code>End_Row=</code>0.n</td>

<td>Set last row to n percent of height</td>
</tr>

<tr>
<td><code>+E</code>n

<td>Same as <code>End_Row=</code>n</td>
</tr>

<tr>
<td><code>+ER</code>0.n or <code>+E</code>0.n</td>

<td>Same as <code>End_Row=</code>0.n</td>
</tr>
</table>

When doing test rendering it is often convenient to define a small,
rectangular sub-section of the whole screen so you can quickly check out one
area of the image. The <code>Start_Row</code>, <code>End_Row</code>, <code>
Start_Column</code> and <code>End_Column</code> options allow you to define
the subset area to be rendered. The default values are the full size of the
image from (1,1) which is the upper left to (w,h) on the lower right where w
and h are the <code>Width=</code>n and <code>
Height=</code>n values you have set.
Note: if the number specified is greater than 1 then it is interpreted as an
absolute row or column number in pixels. If it is a decimal value between 0.0
and 1.0 then it is interpreted as a percent of the total width or height of
the image.
 For example: <code> Start_Row=0.75</code> and <code>
Start_Column=0.75</code> starts on a row 75% down from the top at a column
75% from the left. Thus it renders only the lower-right 25% of the image
regardless of the specified width and height.

The <code>+SR</code>, <code>+ER</code>, <code> +SC</code> and <code>
+EC</code> switches work in the same way as the corresponding INI-style
settings for both absolute settings or percentages. Early versions of POV-Ray
allowed only start and end rows to be specified with <code>
+S</code>n and <code> +E</code>n so they are still
supported in addition to <code> +SR</code> and <code>+ER</code>.

When rendering a subset of *columns* (<code>+sc/+ec</code>) POV-Ray generates a full width image and fills the not rendered columns with black pixels. This should not be a problem for any image reading program no matter what file
format is used.

when rendering a subset of *rows* (<code>+sr/+er</code>) POV-Ray writes the full height into the image file header and only writed those lines into the
image that are rendered. This can cause problems with image reading
programs that are not checking the file while reading and just read over
the end.

if POV-Ray wrote the actual height of the partial image into the image
header there would be no way to continue the trace in a later run.

← Older revision		Revision as of 11:18, 13 November 2010
Line 202:		Line 202:

	--[[User:Le Forgeron\|Le Forgeron]] 22:05, 10 November 2010 (UTC)		--[[User:Le Forgeron\|Le Forgeron]] 22:05, 10 November 2010 (UTC)
		+	:* merci for doing the doc updates related to your improvements ... it's been done --[[User:Jholsenback\|jholsenback]] 11:18, 13 November 2010 (UTC)

← Older revision		Revision as of 03:04, 28 May 2010
Line 1:		Line 1:
		+	==Introduction==
	===Command-line Options===		===Command-line Options===
	<p>The reference section describes all command line switches and INI file		<p>The reference section describes all command line switches and INI file

@@ Line 566: / Line 566: @@
 format is used.</p>
-<p>when rendering a subset of *rows* (<code>+sr/+er</code>) POV-Ray writes the full height into the image file header and only writed those lines into the
+<p>when rendering a subset of *rows* (<code>+sr/+er</code>) POV-Ray writes the full height into the image file header and only writes those lines into the
 image that are rendered.  This can cause problems with image reading
 programs that are not checking the file while reading and just read over

← Older revision		Revision as of 22:05, 10 November 2010
Line 124:		Line 124:

	:* Merged correction (writed->writes) back into main document. As well as missing caps on 1st words of last two paragraphs. BTW: It's not necessary to copy the ENTIRE page just the affected section(s) please. --[[User:Jholsenback\|jholsenback]] 03:30, 28 May 2010 (UTC)		:* Merged correction (writed->writes) back into main document. As well as missing caps on 1st words of last two paragraphs. BTW: It's not necessary to copy the ENTIRE page just the affected section(s) please. --[[User:Jholsenback\|jholsenback]] 03:30, 28 May 2010 (UTC)
		+
		+	----
		+	* Can someone check if there is still such system as MS-Dos for 3.7 ?
		+
		+	On MS-DOS with an eight character limit, myscene.pov would render to mysce001.tga through mysce100.tga.
		+	--[[User:Le Forgeron\|Le Forgeron]] 22:05, 10 November 2010 (UTC)
		+
		+	----
		+	* Adding +STP/Frame_Step with #5183 (if/when merged)
		+
		+	=====Subsets of Animation Frames=====
		+	<!--<indexentry "Animation, subsets of frames">--->
		+
		+	<table width="100%">
		+	<tr>
		+	<td width="30%"><code>Subset_Start_Frame=</code>n<!--<indexentry primary "Subset_Start_Frame"><indexentry primary "Subset_Start_Frame, ini-option">---></td>
		+
		+	<td width="70%">Set subset starting frame to n</td>
		+	</tr>
		+
		+	<tr>
		+	<td><code>Subset_Start_Frame=</code>0.n</td>
		+
		+	<td>Set subset starting frame to n percent</td>
		+	</tr>
		+
		+	<tr>
		+	<td><code>Subset_End_Frame=</code>n<!--<indexentry primary "Subset_End_Frame"><indexentry primary "Subset_End_Frame, ini-option">---></td>
		+
		+	<td>Set subset ending frame to n</td>
		+	</tr>
		+
		+	<tr>
		+	<td><code>Subset_End_Frame=</code>0.n</td>
		+
		+	<td>Set subset ending frame to n percent</td>
		+	</tr>
		+
		+	<tr>
		+	<td><code>Frame_Step=</code>n<!--<indexentry primary "Frame_Step"><indexentry primary "Frame_Step, ini-option"---></td>
		+	<td>Set the increment to the frame number, default to 1</td>
		+	</tr>
		+	<tr>
		+	<td><code>+SF</code>0.n<!--<indexentry "+sf">---></td>
		+
		+	<td>Same as <code>Subset_Start_Frame</code></td>
		+	</tr>
		+
		+	<tr>
		+	<td><code>+EF</code>0.n<!--<indexentry "+ef">---></td>
		+
		+	<td>Same as <code>Subset_End_Frame</code></td>
		+	</tr>
		+	<tr>
		+	<td><code>+STP</code>n<!--<indexentry "+stp">---></td>
		+	<td>Same as <code>Frame_Step</code></td>
		+	</tr>
		+	</table>
		+
		+	<p>When creating a long animation, it may be handy to render only a portion
		+	of the animation to see what it looks like. Suppose you have 100 frames but
		+	only want to render frames 30 through 40. If you set <code>Initial_Frame=30</code>
		+	and <code>Final_Frame=40</code> then the clock would vary from 0.0 to 1.0 from
		+	frames 30 through 40 rather than 0.30 through 0.40 as it should. Therefore
		+	you should leave <code> Initial_Frame=1</code> and <code>Final_Frame=100</code>
		+	and use <code>Subset_Start_Frame=30</code> and <code>Subset_End_Frame=40</code>
		+	to selectively render part of the scene. POV-Ray will then properly compute the
		+	clock values.</p>
		+	<p>Similarly, if you only want to render a tenth of the frames, you can use <code>Frame_Step=10</code> to jump over the nine non-rendered frames between the rendered frames.</p>
		+	<p>
		+	Usually you will specify the subset using the actual integer frame numbers
		+	however an alternate form of the subset commands takes a float value in the
		+	range <em>0.0 <=n.nnn <=1.0</em> which is interpreted as a fraction of
		+	the whole animation. For example, <code> Subset_Start_Frame=0.333</code> and
		+	<code>Subset_End_Frame=0.667</code> would render the middle 1/3rd of a
		+	sequence regardless of the number of frames.</p>
		+
		+	--[[User:Le Forgeron\|Le Forgeron]] 22:05, 10 November 2010 (UTC)