SkyPaint User Manual (rev. 1.0)

© 1998, 1999

1 Introduction

Welcome to the SkyPaint User Manual. This online guide provides detailed information about the SkyPaint 3D panorama editing tool. The manual is designed for those people who don't like to read complicated books and would like to try out the program right away.

Tip: If you want to get started fast, read 3. Setting up, 4. Quickstart, and 7. Tips.

Chapter 1, Introduction, presents the basics on SkyPaint and this User Manual. Chapter 2, Installing SkyPaint, describes how to install SkyPaint onto your computer. Chapter 3, Setting up your paint program, explains how to configure your paint program to work with SkyPaint. Chapter 4, Quickstart, provides a simple recipe for getting started fast with SkyPaint. Chapter 5, Using SkyPaint, presents a feature-by-feature description on how to use SkyPaint. Chapter 6, SkyPaint file formats, explains how to use various file formats with SkyPaint. Chapter 7, Tips, provides a variety of useful suggestions that will increase your productivity. Chapter 8, Troubleshooting, lists several ideas for solving problems with SkyPaint. Use the table of contents to quickly jump around the manual.

Tip: Make sure to read the sections in Chapter 6, SkyPaint file formats, that apply to you. For example, if you are a Quake II level author, you need to read the section on Quake II, or if you plan to use Bryce to create panoramas, read the section on Bryce.

1.1 What is SkyPaint?

SkyPaint is a tool that helps you create 3D panoramic images that form seamless, wrap-around, 360° experiences. Since panorama images are stored in a warped format, it is very difficult to directly paint these images and still maintain proper perspective and proportion. SkyPaint lets you interactively choose any view into the panorama and transfers it to your favorite paint program, allowing you to paint that view exactly as you expect it to appear when viewed by a panorama viewer. Once created, these panoramas can be viewed by panorama image viewers, incorporated into VRML worlds, integrated into interactive games, and used with rendering and animation programs.

SkyPaint is a Photoshop-compatible plug-in that makes the creation of 3D panoramic backgrounds as easy as painting traditional images by allowing you to use the features of your favorite paint or imaging application. SkyPaint can be used to touch up Live Picture and QuickTimeVR panoramic images, Bryce panoramas, VRML Backgrounds, Quake II environments, and environment and background maps created by 3D Studio MAX. SkyPaint works with Adobe PhotoShop, JASC Paint Shop Pro, MetaCreations Painter, and Corel PHOTO-PAINT 8, as well as any Photoshop-compatible program.

1.2 Basics

Run SkyPaint by double clicking on the SkyPaint.exe program (found in the folder that you installed SkyPaint into) or by clicking on:

  Start->Programs->SkyPaint->SkyPaint Panorama Editor

SkyPaint starts with a simple panorama already loaded. Click and drag in the main view window to experiment with navigation. Try clicking on the arrow buttons for a simple navigation interface. Click the `New' button to create a new panorama, or click the `Open' button to edit an existing panorama image. Then, click the `Paint' button to launch your favorite paint program (and hide the SkyPaint menu). Now you can use most of your favorite painting tools to edit this view of the panorama from within your paint program. When you are done painting this view and are ready to change to a different view or save the panorama, click on the plug-in menu of your paint program to invoke SkyPaint commands (this varies depending on which paint program you use--see below for details).

SkyPaint maintains a set of six images that together make up a single 360° panorama. These six images represent six adjacent views of an environment from a single point in space-- the view forward, left, right, backward, up and down. The six views form a box that surrounds the view position and when viewed in a panorama viewer create the illusion of a 3D scene.

The painting program (e.g. PhotoShop or Paint Shop Pro) maintains a canvas, which represents an arbitrary view into SkyPaint's panorama. Communication between the painting program and SkyPaint happens when you choose one of the SkyPaint commands from the paint program's plug-in menu (e.g., `Rotate Left' or `Launch SkyPaint'). Typically, choosing a SkyPaint command applies what you have painted to the canvas, changes the panorama, and sends back a new view of the canvas that you can continue to paint.

Note: SkyPaint only works with unlayered, full-color (24-bit) RGB images. You must flatten your image before launching SkyPaint.

1.3 Conventions used in this manual

Since each paint program names their plug-in menus differently, we will use the symbol [plug-in] to represent the appropriate menu name for each program throughout this document. For example:

Photoshop: [plug-in] means Filter->
Paint Shop Pro: [plug-in] means Image->Plugin Filters->
Painter: [plug-in] means Effects->
PHOTO-PAINT: [plug-in] means Effects->

1.4 System requirements

1.5 Differences between the trial and licensed versions

The trial version of SkyPaint may be downloaded from http://www.skypaint.com and tried out. Soon after you decide to buy the product you can click Help->Purchase/License SkyPaint from SkyPaint's toolbar; this will provide you with a form to purchase SkyPaint (and give you a secret password to enable your version).

The trial version of SkyPaint renders a watermark logo in the right view (90º); the licensed version of SkyPaint does not add the watermark:

Also, after some number of saves, the trial version of SkyPaint presents you with a timed reminder that gives you an opportunity to purchase the licensed version of SkyPaint:

Once you purchase SkyPaint and convert your version into a licensed version, you will no longer get the watermarks or reminder messages on save.

2. Installing SkyPaint

To install SkyPaint's self-extracting executable, do the following:

Removing SkyPaint from your computer

To uninstall SkyPaint, click "Add/Remove Programs" found in the Start Control Panel (Start->Settings->Control Panel) or use Start->Programs->SkyPaint->Uninstall SkyPaint.

3. Setting up your paint program

This chapter describes how to configure your paint program to work correctly with SkyPaint. SkyPaint works with any Photoshop 3 plug-in-compatible paint program. This includes:

3.1 Setting up Photoshop

First, install SkyPaint (see 2. Installation). Most likely you have already set Photoshop's plug-in folder and SkyPaint is ready to go. To test this, run Photoshop, create or open a 24-bit, RGB image, and click the `Filter' menu--you should see a `SkyPaint' entry near the bottom. If not, first make sure that the image you created is 24 bit color (Image->Mode->RGB Color). If SkyPaint still does not appear in the Filter menu, make sure that the plug-in folder is set correctly:

Note: The plug-in files are named SkyPaintActivate.8bf, SkyPaintLeft.8bf, etc., and are probably in a folder like: C:\Program Files\Adobe\Photoshop\Plugins\SkyPaint).

Photoshop Preferences--Plug-ins

 

Photoshop's Filter (plug-in) menu

Here is how SkyPaint should appear in your Photoshop Filter menu:

 

Actions and keyboard shortcuts

If you are using Photoshop 4, you can define Actions that let you press a single key to quickly change the view of the panorama. The file SkyPaint.ATN is installed into the main SkyPaint folder (probably something like C:\Program Files\SkyPaint). It contains action definitions corresponding to the Launch SkyPaint, Rotate Left/Right, and Tilt Up/Down menu commands. Load these actions into Photoshop using the 'Load Actions' menu entry on the Actions palette and select the SkyPaint.ATN file. Once loaded, the F6-F10 keys will run SkyPaint. Click `Button Mode' for simplest display (see figure below).

3.2 Setting up Paint Shop Pro

SkyPaint is compatible with JASC's Paint Shop Pro 4.

In Paint Shop Pro, choose the File->Preferences->GeneralPreference, choose `Plugin Filters', and select the folder that you installed the SkyPaint plug-in into (probably something like: C:\Program Files\Paint Shop Pro\Plugins--it contains the files SkyPaintActivate.8bf, SkyPaintLeft.8bf, etc.).

Paint Shop Pro will now display the SkyPaint sub-menu in the Image->Plug-in Filters sub-menu (at the very bottom of the `Image' menu). Note that the 'Image' menu will not be enabled unless you have created or opened an image in Paint Shop Pro. Also, note that the Image->Plug-in Filters->SkyPaint menu entry will not appear unless you have correctly set the plug-in directory.

Hints for using SkyPaint with Paint Shop Pro

Do not invoke SkyPaint if the image you are painting is being masked. Only the unmasked parts of the image will be transferred to SkyPaint, producing bad results.

You might wish to purchase a keyboard recorder/playback program such as Keyboard Express (see http://www.wintools.com) so that you can quickly invoke the SkyPaint menu entries to move the view as you are painting.

3.3 Setting up Painter

SkyPaint is compatible with MetaCreations Painter 5.

Run Painter, and then choose Edit->Preferences->Plug-Ins. Select the folder where you installed the SkyPaint plug-ins.

Painter is not compatible with all Photoshop plug-ins, and you will get an error when starting Painter if you try to use the same plug-in folder for both Painter and Photoshop. If you want to use SkyPaint with both Painter and Photoshop at the same time, do the following:

You can do the same with other compatible Photoshop plug-ins, but beware; you will get an error when starting Painter if you copy an incompatible plug-in into its plug-in folder.

3.4 Setting up Corel PHOTO-PAINT

SkyPaint is compatible with Corel PHOTO-PAINT 8.

  1. Run PHOTO-PAINT
  2. Click "Tools->Options..."
  3. In the Options dialog box, in the list click "Workspace->Plug-ins" from the list of categories
  4. On the Plug-ins page, click the "Add" button
  5. In the "Select a Plug-In Folder" dialog box choose the folder where the filters you want to add are stored (e.g., C:\Program Files\SkyPaint)
  6. Click OK

Hints for using SkyPaint with PHOTO-PAINT

If you've added layers to your image from within PHOTO-PAINT, you must flatten your image before launching SkyPaint (since SkyPaint cannot interpret layers). Click "Object->Combine->Combine All Objects with Background" to flatten your image.

3.5 Using VRML to preview

You do not need a VRML browser to use SkyPaint. However, it may prove helpful in testing and viewing your results. To test if you already have a VRML browser installed, direct your web browser to http://www.skypaint.com/Examples/simple.wrl --this should load a simple VRML world containing a panorama (see image in previous section).

If you don't have a VRML browser or simply want to get a more recent version, you can load from the sites listed below:

Browser/site Description
Cosmo Software - Cosmo Player Most popular and best-of-class
Intervista - WorldView Excellent product.
Live Picture - Viewer Best if you are using Live Picture products
Bob Crispen's VRML site Help and information on VRML
The Mining Company's VRML site General information on VRML
SDSC's VRML Repository General information on VRML

3.6 Using Live Picture to preview

You do not need a Live Picture viewer to use SkyPaint. However, it may prove helpful in testing and viewing your results.

Live Picture has multiple options for viewing.ivr files (e.g., plug-in, Java, etc.). Consult the Live Picture web site for details on how to download their plug-in viewer or use their Java viewer.

4. Quickstart

If you want to just jump right in and play with SkyPaint before reading the manual, try the following (after you have successfully installed SkyPaint):

This should give you the feel of SkyPaint. It is important to understand that the canvas presented by your paint program is simply a window into the panorama image; it is NOT your panorama. To save the panorama, use SkyPaint's `Save' and `SaveAs' commands.

5. Using SkyPaint

5.1 Starting SkyPaint

Run SkyPaint by double clicking on the SkyPaint.exe program or by clicking on Start->Programs->SkyPaint->SkyPaint Panorama Editor. You can find SkyPaint.exe in the folder that you installed SkyPaint into (probably something like C:\Program Files\SkyPaint) or by searching for the file SkyPaint.exe (Start->Find->Files or Folders ).

Note: It is strongly recommended that you exit your paint program before running SkyPaint to avoid potential problems. If you start SkyPaint while your paint program is running, you may experience some minor problems.

Note: If SkyPaint appears with strange colors in the interface (e.g. purplish), then you probably have set your display to "256 colors" display mode. Click Start->Settings->Control Panel, double click on Display, choose the Settings tab, and set your "Color Palette" to >256 colors (e.g., 16 bits or 65536 colors).

5.2 The SkyPaint user interface

The SkyPaint user interface is shown below. This interface appears when you run SkyPaint or when you choose your paint program's "Launch SkyPaint" plug-in menu entry.

The viewing window in the center of the interface is an interactive viewer that allows you to navigate around your panorama. Press and drag the left mouse button while the cursor is in the viewing window to interactively rotate the view. The viewing window is initially loaded with a default panorama (simple_clouds) that can be replaced by using the New or Open commands (see below).

SkyPaint user interface

The arrow buttons allow you to rotate the view in specific directions. For example, clicking on the left arrow rotates the view to the left by 10 degrees. If you hold the button down the view will continue to rotate to the left. You can also press the arrow keys on the keyboard to rotate the view.

The horizontal angle button, , allows you to instantly jump to one of the four predefined horizontal angles: front (0º), left (270º), back (180º), and right (90º).

The vertical angle button, , allows you to instantly jump to one of the three pre-defined vertical angles: up (90º), horizon (0º), and down (-90º).

There are small white tick marks (triangles) along the bottom/horizontal and right/vertical borders of the viewing window. These tick marks show the current horizontal and vertical viewing angles. Notice how these tick marks move as you navigate the view.

SkyPaint's window label contains the file name of your current panorama (e.g., "Sunset in Fiji"). Also, the window title contains an "*" when the file has been modified but not saved; the "*" is removed after you save. The window label also contains the current horizontal and vertical view angles set in the viewing window (e.g., [h=30º v=10º] means that the view is looking 30º to the right of center and 10º tilted up from the horizon).

The first icon on the toolbar is a popup menu that lists the File commands: New, Open, Save, SaveAs, Preferences, and Exit (see below for details). This is identical to `File' on the window menu bar. The second icon is used to launch your paint program; the ENTER key is a keyboard shortcut that does the same thing. You can set which paint program to run in the File->Preferences dialog. The third icon on the toolbar is a popup menu that lists: SkyPaint Help, About SkyPaint, and Purchase/License SkyPaint. This icon is identical to clicking `Help' on the window menu bar.

The sections that follow describe the various commands in detail.

5.3 File

There are two ways to invoke the File menu: the File icon on the SkyPaint toolbar and the File button on the window menu bar. The following sections describe the items in the File pulldown menu.

5.3.1 New

The `New' button (File->new or Control-n) creates a new panorama. After clicking on the `New' button, the "New Panorama' dialog box will appear:

New Panorama dialog

If you plan to paint the image from scratch, it is highly recommended that you start with one of the templates bundled with SkyPaint. Click `From Template..." to get a list of the available templates.

If you choose not to use a template, you will need to decide the resolution of each of the six images of the panorama (front, back, left, right, top, and bottom). High-resolution images look better, but take up more memory and disk space. Some hints for choosing image size:

After typing in a resolution, press the 'tab' key to recalculate the memory that will be used at that resolution.

5.3.2 Open

The `Open' button (File->Open or Control-o) lets you open an existing panorama for editing. The "Files of type:" menu determines which types of files the Open dialog will display and how these files are interpreted.

Avoid working in the formats that are not marked 'Exact' in the following table. Repeatedly opening and saving JPEG files will result in degradation of image quality, due to the nature of JPEG image compression. Repeatedly opening and saving files containing cylindrical or spherical panoramas will also result in image degradation, because SkyPaint uses a different representation (cubic) internally. See the Tips section for tips on working with JPEG or spherical panoramas.

The table below describes the various options:

 Files of type:  Exact?  Description
VRML Background, PNG  Yes Lists all PNG files with "_FR" ("front") suffix. Reads the six images: xxx_UP.png, xxx_DN.png, xxx_LF.png, xxx_RT.png, xxx_BK.png, and xxx_FR.png. Does not read .wrl file.
VRML Background, JPEG  No Same as above, but for JPEG images.
Quake II, Targa

 Yes
 Lists all Targa images with "ft.tga" suffix. Assumes the images follow Quake II environment map conventions. Reads the six images: xxxft.tga, xxxbk.tga, xxxup.tga, xxxdn.tga, xxxlf.tga, and xxxrt.tga.
3DStudio, Targa  Yes Same as VRML, but for Targa images.
Live Picture Background,
JPEG		  No Same as VRML, JPEG. Does not read .ivr file.
Live Picture Background,
BMP		  Yes Same as above, but for BMP images.
Live Picture (Vista node),
SPHERE/CYLINDER,
JPEG		 No  Lists all JPEG images. Guesses whether the image is type "SPHERE" or "CYLINDER" based on the image aspect ratio (see 7.3 Live Picture format). Does not read .ivr file.
Live Picture (Vista node),
SPHERE/CYLINDER,
BMP		 No  Same as above, but for BMP images.
Live Picture (Vista node),
CUBE, JPEG		  No Lists all JPEG images, assumes they are Live Picture cubic images (six sub-images stacked on top of one another in a single JPEG file). Does not read .ivr file.
Live Picture (Vista node),
CUBE, BMP		 Yes  Same as above, but for BMP images.
Bryce/QTVR, BMP  No Lists all BMP images. Assumes the image is a Quicktime VR cylindrical projection generated by Bryce.
Quicktime VR, BMP

 No
 Lists all BMP images. Assumes the image is a Quicktime VR cylindrical projection.

5.3.3 Save

Clicking on the `Save' button (File->Save or Control-s) will save your current work. Notice that SkyPaint's window title contains an "*" when the file has been modified but not saved; the "*" is removed after you save. Save automatically saves to the current file and type that was last opened (when this is not possible, Quicktime VR, the SaveAs dialog prompts you for an output type--see SaveAs below).

5.3.4 SaveAs

The `SaveAs' button (File->SaveAs) allows you to change the name of the output panorama, to change the type of panorama file that you save, and to save your file. Note that you do not need to type the file type extension (e.g., .wrl) into the name field; SkyPaint will automatically write the files with the appropriate file conventions and extensions based on the file type that you select. For example, if you are saving to VRML type "foo" for the name and SkyPaint will write foo_FR.jpg, foo_BK.jpg, etc.

Avoid working in the formats that are not marked 'Exact' in the following table. Repeatedly opening and saving such files will result in degradation of image quality. See the Tips section for tips on working with inexact formats.

The following table describes in detail the various options:

 Save as type  Exact?  Description
VRML Background, PNG  Yes Writes xxx.wrl containing a single Background node and writes six PNG images following VRML conventions: xxx_UP.png, xxx_DN.png, xxx_LF.png, xxx_RT.png, xxx_BK.png, and xxx_FR.png.
VRML Background, JPEG  No Same as above, but for JPEG images.
 Quake II, Targa

 Yes
 Writes six Targa images following Quake II conventions: xxxup.tga, xxxdn.tga, xxxlt.png, xxxrt.tga, xxxbk.tga, and xxxft.tga.
3DStudio, Targa Yes  Writes six Targa images following 3D Studio conventions: xxx_UP.tga, xxx_DN.tga, xxx_LF.tga, xxx_RT.tga, xxx_BK.tga, and xxx_FR.tga.
Live Picture Background (node),
JPEG		  No Writes xxx.ivr containing a single Background node and writes six JPEG images: xxx_UP.jpg, xxx_DN.jpg, xxx_LF.jpg, xxx_RT.jpg, xxx_BK.jpg, and xxx_FR.jpg.
Live Picture Background (node),
BMP

Yes

 

 Same as above, but writes BMP files.
Live Picture (Vista node), CYLINDER/SPHERE,
JPEG		 No  Writes xxx.ivr containing a single Vista node of type "SPHERE" and writes a single JPEG image xxx.jpg. Does not output type "CYLINDER."
Live Picture (Vista node,) CYLINDER/SPHERE,
BMP		 No  Same as above, but writes out a BMP file. Does not output type "CYLINDER."
Live Picture (Vista node), CUBE, JPEG No  Writes xxx.ivr containing a single Vista node of type "CUBE" and writes a single JPEG image xxx.jpg.
Live Picture (Vista node), CUBE, BMP  Yes Same as above, but writes out a BMP file.

5.3.5 Resize Panorama

The `Resize Panorama' button (File->Resize Panorama) allows you to set the image resolution of your current panorama. This dialog allows you to set the size of the "front" image (one of the six created for cubic panoramas) and the size of the single spherical panorama. In the case of cubic panoramas (e.g., VRML, Quake II, and 3D Studio), all six images are set to the same resolution.

5.3.6 Preferences

The `Preferences' button (File->Preferences) allows you to set three values: "Paint Program", "Plugin Path", and "Plugin Left/Right/Up/Down Rotation":

 Setting  Description                                                                       
Paint Program Set this to the .exe of your paint program (e.g., C:\Program Files\Adobe\Photoshop\Photoshp.exe).
Plugin Path Set this to the folder that contains your Photoshop plug-ins (e.g., C:\Program Files\Adobe\Photoshop\Plugins).
Plugin Left/Right/... Set this to the amount of rotation you want the Rotate Left, Rotate Right, Tilt Up, and Tilt Down plug-in commands to move the view.

5.3.7 Quit

The `Quit' button exits SkyPaint. If you have not saved your work, SkyPaint will ask you.

Important: After you exit SkyPaint, your paint program may ask you to save the image that you've been painting since it has no idea that SkyPaint has already saved it for you. In most cases, you should answer "No" to this query.

5.4 View menu

The View menu (found on the window menu bar) includes the following commands:

 Menu entry  Description
 Paint this view...  Same as `paint' button (see below).
 Forward  Moves view to "forward" view [h=0º v=0º]
 Right  Moves view to "right" view [h=90º v=0º]
 Back  Moves view to "back" view [h=180º v=0º]
 Left  Moves view to "left" view [h=270º v=0º]
 Up  Moves view to "up" view [h=0º v=90º]
 Down  Moves view to "down" view [h=0º v=-90º]

5.5 Paint

The paint button launches your paint program and sends the current view into the panorama to the paint program. Pressing the enter key on the keyboard is the same as pressing the `paint' button.

The first time you click `Paint' for a new or recently opened file, a "Choose size" dialog will appear. This dialog allows you to choose the width and height of the canvas.
SkyPaint selects a reasonable default, but allows you to change it. The wider the canvas, the wider your field-of-view, allowing you to paint more of the panorama at once. However, very large canvases will show an exaggerated perspective.

5.6 Help

There are two ways to invoke the Help menu: the Help icon on the SkyPaint toolbar and the Help button on the window menu bar.

The `Help' menu has three entries:

 Menu entry  Description                                             
 SkyPaint Help... Launches your Web browser to present this documentation
 About SkyPaint... Displays the version of SkyPaint you are running
 Purchase/License SkyPaint... Launches your Web browser to a page that allows you to purchase/license SkyPaint. You need an Internet connection for this to work properly.

5.7 The SkyPaint plug-in menu

The SkyPaint plug-in menu is found inside your paint program's user interface

 Paint Program  Menu command
 Photoshop  Filter->SkyPaint->...
 Paint Shop Pro  Image->Plugin Filters->SkyPaint->...
 Painter/PHOTO-PAINT  Effects->SkyPaint->...

There are five commands on the SkyPaint plug-in filter menu (shown here running in Photoshop and described below in the table):

 Plug-in Command  Description
 Launch SkyPaint Launches the SkyPaint user interface and applies what you have painted to the panorama.
 Rotate Left Applies what you have painted to the panorama stored in SkyPaint, rotates the panorama view to the left, and returns the new view to your paint program.
 Rotate Right Same as above, but rotates view to the right.
 Tilt Up Same as above, but tilts view upward.
 Tilt Down Same as above, but tilts view downward.

The view rotation/tilt increment can be changed in SkyPaint by choosing the File->Preferences command. The rotate and tilt commands do not launch SkyPaint's main window.

6 SkyPaint file formats

SkyPaint reads and writes several different file formats. The following table summarizes the supported formats, and the following sections give details on each of the formats.

 Format Read? Write? Notes
VRML Yes Yes JPEG (.jpg) or PNG (.png) images; writes Background nodes only.
Quake II

 Yes

 Yes
 Targa (.tga) environments only.
3DStudio Yes Yes Targa (.tga) environment maps and backgrounds only.
 Live Picture Yes Yes Vista nodes (CUBE, CYLINDER, and SPHERE) and Background nodes; JPEG (.jpg) and BMP (.bmp) images.
 Bryce/QTVR

 Yes

 No
 Import-only of Bryce QTVR
Quicktime VR

 Yes

No 
 Import-only

6.1 Using VRML

SkyPaint reads and writes panorama images in the format required by the VRML Background node. VRML assumes that the Y-axis is up, -Z is the default view direction, and defines Background nodes as six images representing the inside faces of an infinite cube that surrounds the viewer:

 Image  View Direction  File convention
 front

 -Z
  "_FR" suffix
 back

 + Z
  "_BK" suffix
 left

 -X
  "_LF" suffix
 right

 +X
  "_RT" suffix
 top

 +Y
  "_UP" suffix
 bottom

 -Y
  "_DN" suffix

When SkyPaint saves a panorama as VRML, it saves:

For example, if you use SkyPaint to save a panorama named 'xxx' as a VRML file with PNG images, then 'xxx.wrl' will look like this:

#VRML V2.0 utf8
Background {
  frontURL  "xxx_FR.png"
  backURL   "xxx_BK.png"
  leftURL   "xxx_LF.png"
  rightURL  "xxx_RT.png"
  bottomURL "xxx_DN.png"
  topURL    "xxx_UP.png"
}

Important: Be careful not to let SkyPaint overwrite a VRML file that contains other content besides the one Background node.

If you want to use this Background in a larger world, you must copy and paste the Background node definition into the main world's .wrl file, and move the image files so that they are in the same directory as the larger world.

Note: The naming convention required by SkyPaint (_FR/_BK/...) is not required by VRML. However, SkyPaint will not find image files unless you follow these conventions.

You can choose either PNG or JPEG formats for the image files. The PNG image format is a portable, cross-platform file format. PNG is a lossless format-- reading, modifying and writing out PNG files does not cause them to lose any quality. The JPEG (also known as JFIF) image format uses 'lossy' compression to make the files smaller; JPEG files are smaller than PNG files, but repeatedly reading and rewriting JPEG files will make the image quality deteriorate.

SkyPaint does not read VRML files (.wrl). Rather, it reads the six images that VRML files refer to through the Background node if those images follow the SkyPaint naming conventions (_FR/...). When SkyPaint lists files for opening, it lists any file that has an _FR" suffix and assumes that the other five images exist. If any of the other images do not exist, SkyPaint will fill in with a white background.

6.2 Quake II

SkyPaint reads and writes Quake II environments. Quake II expects six 24-bit Targa images with the following file name suffixes: "ft", "bk", "lf", "rt", "up", and "dn". For example, the following six images are saved by SkyPaint if the file name "xxx" is typed:

xxxft.tga
xxxbk.tga
xxxlf.tga
xxxrt.tga
xxxup.tga
xxxdn.tga

Note: The Quake II convention for the "front" image is "ft" instead of the "_FR" used by VRML and 3D Studio MAX.

SkyPaint saves Quake II images in the Targa image format (.tga). Targa is a loss-less (full 24-bit) format. Quake II also requires 8-bit PCX versions of these same six images. See the Creating Quake II environments Using SkyPaint for an explanation of how to create the PCX versions of the six images. When you are done, you will have twelve images in all, six 24-bit Targa images and six 8-bit PCX images.

Tip: Wait until you are completely done editing the 24-bit Targa version before generating the 8-bit PCX images.

The orientation and arrangement of the six images is different from both VRML, Live Picture, and 3D Studio MAX.

See Creating Quake II environments Using SkyPaint for detailed instructions on how to use SkyPaint to create and edit Quake II environments.

6.3 3DStudio MAX

SkyPaint can read and write 3DStudio MAX cubic environment maps and backgrounds. These are almost identical to VRML Backgrounds, except that the "front" and "back" images are swapped and they are stored as six Targa (.tga) image files. The image file naming convention is similar to VRML files-- the front image is named "xxx_FR.tga", etc. However, "front" refers to the front of the cube when viewed from the outside and similarly for "back". Thus, "front" and "back" are reversed from the VRML convention. The following table shows how the 3DStudio file naming convention corresponds to the VRML file naming convention:

 3DStudio

 VRML

xxx_BK.tga

xxx_FR.png

xxx_FR.tga

xxx_BK.png

xxx_LF.tga

xxx_LF.png

xxx_RT.tga

xxx_RT.png

xxx_UP.tga

xxx_UP.png

xxx_DN.tga

xxx_DN.png

SkyPaint cannot read or write other types of 3D Studio MAX files (such as .3ds files that contain 3D geometry).

See Using Panoramas as 3DStudio MAX Backgrounds for detailed instructions on using SkyPaint panoramas with 3DStudio.

6.4 Live Picture

See 5.3.2 and 5.3.4 for details on which Live Picture image formats SkyPaint reads and writes.

The vertical field-of-view for images corresponding to Vista nodes (type "SPHERE" and "CYLINDER") is inferred from the dimensions of the image, by assuming that the horizontal size represents a full 360 degrees and that the pixels in the image have a square aspect ratio. For example, an image that is 360 by 180 pixels is assumed to be a spherical panorama (because a spherical projection represents 360 degrees around and 180 degrees up and down); any other image with a two-to-one aspect ratio is also assumed to be a spherical projection.

We recommend that you save as type "Live Picture, Background" or "Live Picture, CUBE" while editing. If you wish to save as type "Live Picture, SPHERE/CYLINDER", it is recommended that you wait until you are done editing before saving as this type to avoid converting back and forth too often.

Note: SkyPaint cannot read or write field-of-view settings from Vista nodes inside the Live Picture .ivr file. The vertical field-of-view is inferred from the width of the image.

6.5 Importing Bryce/QTVR panoramas

Bryce (versions 2 and 3D) by MetaCreations, Inc. is a tool for generating images of natural outdoor scenes. SkyPaint can import Bryce/QTVR BMP images, but cannot SaveAs Bryce/QTVR yet. Here's one recommended workflow:

Tip: Sometimes Bryce gets confused and renders the scene as a "Perspective Rendering" even though you have set the Render Options to "360° Rendering". When it is working properly the scene should show strong perspective distortions and render a full 360° view. To fix this, simply set Render Options back to "Perspective Rendering", start a render and quickly stop it. Then, set Render Options back to "360° Rendering", and render your scene.

See Creating 3D Panoramas with Bryce for another workflow that produces higher-quality, full 360° panoramas.

6.6 Importing Quicktime VR panoramas

SkyPaint can read Quicktime VR panoramas in BMP image format. These images are assumed to be cylindrical projections with square pixels. SkyPaint infers the the vertical field-of-view from the aspect ratio of the image.

QuickTime VR tools typically export panoramas as PICT images. Use your paint program or any popular image format conversion tool to convert the PICT file into a BMP file to read it into SkyPaint.

6.7 Games or other application development

Note: See section the on Quake II for details on using SkyPaint to create and edit Quake II environments.

The six images created by SkyPaint are ordinary, 90-degree perspective projections of the background, making it easy to use them with most 3D game engines and 3D texture-mapping hardware. Instead of clearing the background to a constant color before drawing the game's scene, just draw the inside of a large cube, rotated appropriately for the user's view and texture mapped with the SkyPaint images.

Some hints and issues:

Note: Please give us feedback on what other file types you think SkyPaint should be able to read and/or write, support@skypaint.com

7. Tips


Notice the slight blurring and raggedness of the letters in the image on the right.

Aliasing will be worse if the resolution of your canvas is as large or larger than the resolution of the panorama images. You can minimize aliasing by increasing the resolution of the panorama images and by using a canvas that is no bigger than each of the six images of the panorama.

If you are working with spheric panoramas, you might notice a lot of aliasing or blurring near the north and south poles, where a large number of pixels in the source image correspond to a very few pixels on the canvas.

8. Troubleshooting

SkyPaint plug-in does not appear in the plug-in menu

See 3. Setting up your paint program.

'Access Denied' error when Paint command

This means the SkyPaint does not know where your paint program is installed. Use the `Preferences' dialog and give the full path to your paint program.

SkyPaint menus/actions are disabled

Remember that SkyPaint requires that the paint canvas (in your paint program) be a 24-bit, RGB image. This usually happens because you have changed the image canvas in your paint program to a type that is not a 24-bit, RGB image or have added layers using Photoshop. If you have added layers, flatten the layers before invoking SkyPaint.

Photoshop complains "cannot recognize the file extension"

Photoshop will not be able to read the "Temp_SkyPaint.bmp" file that SkyPaint writes out if it cannot find the "BMP8B.8BI" file (which comes with Photoshop) somewhere inside its plug-ins folder. Either make sure you install the SkyPaint plug-ins into the main Photoshop plug-ins folder, or copy the "BMP8B.8BI" plug-in into the same folder as the SkyPaint plug-ins if for some reason you are using a different plug-in folder with Photoshop.

Wrong image was transferred back to SkyPaint

Remember that SkyPaint assumes that the whatever image is active in your paint program is the image to be transferred. Therefore, if you have accidentally selected the wrong image inside your paint program and then invoked SkyPaint, the wrong image can be transferred to SkyPaint.

If you have any problems, please send email to: support@skypaint.com.

September 6, 1999