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--- 01_user_documentation:08_light:03_external:01_pov [2025/02/07 11:25] – created gaetan
+++ 01_user_documentation:08_light:03_external:01_pov [2025/02/07 11:25] (current) – gaetan
@@ Line 4: / Line 4: @@
 POV-Ray is a free ray-tracer. The POV-Ray plugin defines an export of a 3D scene to POV-Ray's file format, this can be used to obtain high-quality images of scenes modeled with GroIMP.
-====== ======
+===== Installation of POV-Ray =====
-{{namespace>:01_user_documentation:08_light:03_external:01_pov}}
+POV-Ray is available for download at [[http://www.povray.org]]. For GroIMP's POV-Ray plugin, you need POV-Ray version 3.5 or higher. Please follow the instructions given at POV-Ray's web page in order to install POV-Ray properly.
+** Note: Most Linux distributions contain POV-Ray. Just select it in the setup tool of your distribution, POV-Ray will then be installed automatically. **
+===== Configuration =====
+If the POV-Ray executable file is named //povray// and
+is contained in one of the directories specified in the PATH-variable  of your
+system, no further configuration of GroIMP is necessary. This is the case for
+most UNIX-like systems, but normally not for Windows systems.
+{{:pov:preferences.png}}
+** Figure 1: Configuration of the POV-Ray plugin **
+The configuration of the POV-Ray plugin is done in the
+Preferences panel, see Figure 1. In
+the field "Programme", enter the path to POV-Ray's executable file. For Windows
+systems, this is typically
+"C:\Path to POV-Ray Installation\bin\pvengine.exe". The field
+"Command line" allows you to specify
+some options for POV-Ray, which may, e.g., influence rendering quality; please
+consult POV-Ray's documentation. Finally, the option "Use standard output"
+controls how the rendered image is transferred from POV-Ray to GroIMP: If
+POV-Ray's standard output is used, the image is transferred continuously, so
+that a progressive display within GroIMP is possible. Without standard output,
+POV-Ray writes its output to a temporary file, which is displayed at once after
+completion of the ray-tracing process. Generally, the method using standard
+output is preferable; however, there is a bug in (some versions of) POV-Ray for
+Windows, which corrupts image data in the output. If you see unexpected colors
+in the rendered image, deactivate this option.
+** Note: POV-Ray for
+Windows is equipped with a graphical user interface for editing POV-Ray scenes
+etc. Unfortunately, this graphical user interface is always shown, even when
+POV-Ray is only used in batch mode, as is the case for GroIMP. Depending on
+POV-Ray's configuration, POV-Ray may even keep running after the rendering has
+completed. If this is the case, add the option // /exit// in the
+field "Command line". The option // /nr // keeps POV-Ray from
+restoring previous edit sessions, which may reduce startup
+time. **
+===== Using the Plugin =====
+GroIMP's POV-Ray plugin is used in two ways: At first, it
+defines an export to POV-Ray's file format. This is available via
+// View/Export// in the 3D view. You have to specify a
+file name for the output, the POV-Ray scene will then be written to this
+file. Some scenes contain additional image files, they will be written into a
+subdirectory called ''scene.pov-files'' (where
+<filename>scene.pov</filename> is the file name you have
+chosen).
+Secondly, this export is used to obtain a POV-Ray-rendered
+image of the current scene directly in GroIMP's 3D view. Just use the menu
+//Render View/POV-Ray// in the 3D
+view.
+===== Limitations =====
+D geometry and 3D materials are complex objects.
+Therefore, a 1:1 translation of one
+representation of 3D scenes to another is almost always impossible. All of
+GroIMP's geometry can be exported to POV-Ray, however, some objects like NURBS
+surfaces have to be exported as triangle meshes because POV-Ray does not
+support them directly. This leads to quite big POV-Ray file
+sizes.
+The export of GroIMP's materials to POV-Ray is even more
+restricted. For some material definitions, it is not possible to export all of
+their parts to POV-Ray, so POV-Ray's output may look different from what you
+would expect. Manual postprocessing of exported POV-Ray-scenes may be
+necessary.