The Datafile PD-CD 5/DATAFILE_PDCD5.iso/utilities/p/povshade/!Help+/help_on/!Shade4

Text File | 1995-06-20 | 7.9 KB | 255 lines

@page:contents@!Shade4 Contents





    @Sprite:Wyvern@
      _______________________________________________________

   This Help file describes the use of !Shade4, a support application
   for !Ray3d-Pro which will take a scene file and produce an ASCII
   file suitable for the Public Domain raytracer, RayShade.

        @goto:Intro:  Introduction           @
        @goto:tut:  Tutorial               @
        @goto:Using:  Using !Shade4          @
        @goto:options:  Raytracing options     @
        @goto:Copyright^contents:  Copyright              @



@end@
@Page:Intro@Introduction

@Colour:11@   Introduction

   Originally, !Ray3d-Pro was written as one complete application,
   which could raytrace your scenes on a number of different PD
   raytracers.

   However, it soon became apparent that if I was to enable the program
   to cater for an additional raytracer at a later date, I would need
   to re-release a new version of !Ray3d-Pro.

   This would have two problems:

   * The size of the Ray3d-Pro application would continue to grow,
     and ultimately become too large for base level machines.

   * I would need to distribute the new version.

   So I decided to break the program down into several applications,
   namely the scene designer, and the raytracing applications of which
   Shade4 is one.

   The advantages of this are:

   * The size of the main !Ray3d-Pro application would remain fixed.

   * New Raytracing applications could be released.

   * Raytracing can now be done without !Ray3d-Pro being loaded. This
     releases a substantial amount of memory for the raytracers, and
     therefore allows bigger scenes to be raytraced.

@end@
@page:using@Using !Shade4

@colour:11@   Using !Shade4

   To raytrace a scene using this application simply drop a scene file
   which has been created with !Ray3d-Pro, onto the !Shade4 icon on the
   icon bar.

   A normal RISC OS save window will appear which allows you to specify
   where to save the ASCII file which can be loaded into !Rayshade for
   raytracing .

   If you try to save the ASCII file over an existing scene file, a
   requestor will appear allowing you to Cancel the operation, or
   overwrite the scene file.

   Note that the ASCII file cannot be re-loaded into Ray3d-Pro and so if
   you want to continue editing the scene, you must keep the scene file.

   Many @goto:options:raytracing options@ are available by selecting
   "options" from the icon bar menu.

@end@
@Page:fov@Field of View

@Colour:11@   Field of View

   This controls how much of an angle will be between the left and
   right sides of the image. setting this to 360° would mean that
   you could see in a full circle.

@end@
@Page:ambience@Ambience Lighting

@Colour:11@   Ambience Lighting

   This controls the amount of background lighting there is. Higher
   values mean the whole scene is lighter.

@end@
@Page:depth@Depth of Field

@Colour:11@   Depth of Field

   This option allows you to set the depth of field for the scene
   to be raytraced. The depth of field controls the amount of focus
   blur which is present in the final image. Objects close to the
   observer appear in sharp focus, while those further away appear
   blurred.

   A value of 0 results in a pinhole camera, where no blur will take
   place in the scene. Values greater than 0 result in a greeater
   amount of blurring to take place.

@end@
@Page:Grid@Grid

@Colour:11@   Grids

   This option determines whether grids will be used by RayShade for
   raytracing. Grids speed up raytracing for complex scenes, but also
   take more memory. If you get an 'out of memory' error, turn this
   option off.

@end@
@page:options@Raytracing Options

@colour:11@   Raytracing Options

     @goto:Grid:  Grids                  @
     @goto:fov:  Field of View          @
     @goto:ambience:  Ambience Lighting      @
     @goto:depth:  Depth of Field         @
     @goto:quality: Quality                 @

@end@
@page:quality@Quality

@colour:11@   Quality

   In this section of the options window are four option buttons. When
   each of these is on, !Shade4 will create the ASCII file with the
   relevant information to raytrace that aspect of the scene. If the
   options are off, then the picture quality will be poorer, but the
   raytracing time will be reduced.

   The following descriptions are true when the option is turned OFF.

@colour:08@   Lights      @colour:07@- This removes lights from the scene, so that all obects
                 have the same amount of light cast upon them.

@colour:08@   Textures    @colour:07@- Removes textures such as wood, marble, checker, etc.
                 Greatly improves the rendering time.

@colour:08@   Reflections @colour:07@- Stops reflected rays from being calculated. Only
                 has any effect if a scene cnntains mirrored objects.

@colour:08@   Refractions @colour:07@- Stops refracted rays from being calculated. Only
                 has any effect if a scene cnntains transparent objects.

@end@
@page:tut@Tutorial

@colour:11@   Tutorial

   So, you've just spent ages designing a scene using !Ray3d-Pro and you
   want to raytrace it - but you don't know how to.

@colour:08@   Step 1

   The easiest way to raytrace a scene is to simply drag the Ray3d-Pro scene
   file from the disc onto the !Shade4 icon on the icon bar.

   A normal RISC OS save box will appear, and you should save the file
   back to the disc. This is an ASCII file which can now be loaded into
   the !Rayshade application (written by Craig Kolb), which will raytrace
   the scene.

@colour:08@   Step 2

   OK, you want to alter some of the raytracing options, and make the
   raytracing time smaller perhaps?

   Click the MENU button over the icon on the icon bar, and you will
   see a menu with the following options.

     @goto:info: Info       ⇨ @
     @goto:options: Options...   @
     @goto:save: Save opts    @
     @goto:quit: Quit         @

   Selecting "Options" will bring up a window where various options can
   be set. (click on options above, to get more info).

   When you have altered the options you require, follow the same
   procedure as in Step 1.

@end@
@page:save@Save options

@colour:11@   Save options.

   Choosing this menu item will save all of your current raytracing
   options to disc, so that when !Shade4 is re-loaded at a later date,
   all of the options will be as they are now.

@end@
@page:quit@Quit

   @colour:11@Quit

   Selecting this option will quit the !Shade4 application.

@end@
@page:info@Info

   @colour:11@Info

   This displays information about the !Shade4 application, such as the
   version number and Author.

@end@
@page:glossary@Glossary

   @colour:08@!Ray3d-Pro

   !Ray3d-Pro is a scene designer which allows you to create a scene
   in three dimensions, which can then be raytraced using !RayShade.

   @colour:08@Raytracing

   Raytracing is the technique used for generating realistic pictures
   from a 3d scene. Each ray of light is traced from where it ‘hits’
   the scene, back to the light source it came from. This process then
   ensures that the scene generated is close to real life because it
   follows the same physical laws.

   @colour:08@Depth of field

   Depth of field is the term given to the way that objects in the
   distance appear fuzzy and out of focus, while objects a specific
   distance away appear clear.

   @colour:08@Ambience light

   Ambience light is the term given to the amount of background light
   present in a raytraced picture.

   If the value specified is too low then a scene will appear dark,
   while s value which is too high will cause a washed out appearance.

   @colour:08@Field of view

   Field of View is the angle that your eyes can see. If you had a
   field of view which was 360° then you would be able to see in a
   full circle, including things that were behind you.

@end@