Content Creation Guidelines

New datasets are always welcome for Science On a Sphere®! Here are a few simple guidelines to assist in the creation of content. The SOS team has significant experience with technical and aesthetic issues when creating content for spherical display systems, and is happy to provide feedback and suggestions during production to ensure quality content.

Part 1 covers useful information for creating content
Part 2 outlines the steps for adding a new dataset to the SOS catalog

Part 1 - Creating New Content

Data Format

There are two basic types of datasets for SOS:

Texture - Single Image

Textures can be displayed on the sphere and rotate around the poles of the sphere, as in planetary rotation. A good example of a texture is Mars. In the Mars folder you will find just one image, named for its resolution, which is projected on the sphere. Often, the textures are available in several different resolutions. As the resolution increases, so does the loading time on the sphere. Textures can be rotated in any way using the functions either in the Control menu of the SOS Stream GUI or in the remote, and by default rotate around the poles of the sphere. Textures will rotate indefinitely until pause is pressed or another dataset is loaded.

Time Series - Image Sequence or MPEG4

There are several different ways that time series work. In its raw form a time series is an image sequence. SOS will display in sequential order all the images in a single directory. The images can also be converted to a MPEG4. This is the preferred format for showing time series because the system can play the MPEG4 files at a higher resolution and faster frame rate than the image sequences and they take up less disk space. There is no limit to the length of a time series. Time series by defualt don’t rotate, but can also be set to rotate while they are animating through a feature in the playlist and a button on the remote. Transitions, special effects, and other computer graphics techniques can be added to a sequence through the use of off the shelf software like Final Cut Pro. Time series will loop indefinitely until pause is pressed or another dataset is loaded.

NOTE: Even if you make an MPEG4, it’s good to keep the image sequence, if available.

Map Projection

The map projection used is the Equatorial Cylindrical Equidistant projection. This is a simple latitude/longitude grid with the lines evenly spaced where the image is twice as wide as it is tall. To be consistent with the SOS Data Catalog, it is recommended that the 0° line go through the middle of the map, with the +/-180° lines at the edges. In order for the data to wrap properly around the sphere, it is imperative that you follow the specifications for the data format closely. Images in the wrong format will project on the sphere, but they will not correctly represent the size of the continents.


Image Format

SOS will accept most common formats (JPEG, PNG, GIF, TIFF, etc.), but JPEG and PNG are preferred for images and image sequences. In addition to pointing to files that are local on your computer, you can also use URLs, such as http://example.com/image.jpg.

Video Format

Render the video with the MPEG4 video codec at a minimum of 25 mbps. Just because a file has a .mp4 extension does not mean it will play perfectly on SOS. Be sure to check the codec that was used to render the file. The H.264 codec should not be used because it can cause errors in the SOS software.

Alternative Formats – KML and WMS

The software also has the ability to display KML (Keyhole Markup Language) files and load images directly from an Open GeoSpatial Consortium (OGC) Web Mapping Service (WMS) on Science On a Sphere. The Dataset Manual contains more details about these formats. 

Audio Format

The audio player for SOS is fairly versatile and most common formats will work with SOS, such as mp3, mpeg4, wav, ogg, and aif. The audio file can either be a standalone file or embedded in the same MPEG4 file as the video.

Resolution

The recommended resolutions are 2048x1024 for time series and 4096x2048 for textures, though other 2x1 resolutions, such as 3000x1500 will work. Higher resolutions are possible, but older SOS systems won't be able to load them well. Make sure to render the videos with square (1:1) pixels for proper playback. If possible, the highest resolution of the animation that is generated should also be provided, in addition to the 2048x1024 file, so that it is available for new and upgraded sites that have the ability to play them.

The SOS software is capable of working with higher resolution 4K projectors on upgraded systems. Movies with 4096x2048 resolutions will work on such systems, although decreased FPS rates may be necessary and the load time will be longer. Single images of 8192x4096 display well on 4K systems and images as large as 16384x8192 will work, although resolutions above 8192x4096 will result in only slightly increased quality. We recommend that you test any high resolution images and movies you create on a full 4K projector system to ensure they will display as you expect.

Dataset Considerations

Orientation of Datasets

The maps created for SOS should be centered on the Prime Meridian, so that 0°N,0°E is the center of the image, as seen below left. The center of the map loads between projectors three and four with the edges of the map lining up between projectors one and two, as seen in the diagram to the right of the map.

Seams

It is important that the data fill the entire image space. If there are borders or extra space around the edges then a seam will appear on the sphere with spots on the poles. It is also important that the data match on either side of the edges of the image. If you don’t take this into account, you’ll end up with seams like the ones shown here:

       

In addition to making sure that the data fills the entire frame, from 180° West to 180° East, also make sure that the data fills the entire frame from 90° South to 90° North. If there is missing data at the poles, fill in the area with a solid color or a basic land/ocean background to ensure that the dataset wraps properly around the sphere without stretching vertically.

Warping

When working with a spherical surface, warping is always something to consider. The least amount of warping occurs near the equator, while the most warping occurs at the poles. Because of this, it is recommended that any text and labels are placed near the equator. Supplementary text, labels and images that are displayed as PIPs don’t warp if their position is set with the pipcoords attribute in the playlist. Datasets can be tested for warping issues using CC Sphere in Adobe After Effects or 3D Sphere in Photoshop. There are some plugins for After Effects such as Cycore Effect’s Sphere Utilities that can also help with spherical warping. In addition, these programs can be used to check for seams.

Frame Rate

You can animate a time series at any rate, but 30 frames per second is the recommended speed. The optimal playback speed is chosen based on the number of frames and the degree of change between each frame in the sequence. To get smooth time series, the changes between each frame should be small and the playback speed high. If a time series is coarse, then it might animate better at a slower frame rate such as 10 – 15 fps.

Labels and Colorbars

Labels and colorbars are important for providing context. For every dataset that needs a timestamp, a file called labels.txt should be generated that contains one line for each frame in the animation. A labels.txt file cannot be used with a single image. Typically the labels include the date, but can contain any desired information, as seen below. Labels should not be “burned in” the images themselves due to warping. Also, when labels are “burned in” they can be rotated out of view and tilted at odd angles when a presenter is interacting with the sphere.

07/24/2004 06:45 
          07/24/2004 07:00
          07/24/2004 07:15 
          07/24/2004 07:30 
          07/24/2004 07:45
          07/24/2004 08:00
          07/24/2004 08:15 
          07/24/2004 08:30 
          07/24/2004 08:45    
SSEC 08/31/2005 Katrina
          SSEC 08/31/2005 Katrina
          SSEC 08/31/2005 Katrina
          SSEC 08/31/2005 Katrina
          SSEC 08/31/2005 Katrina Maria
          SSEC 09/01/2005 Maria
          SSEC 09/01/2005 Maria
          SSEC 09/01/2005 Maria
          SSEC 09/01/2005 Maria

Colorbars and legends can be added using the picture-in-a-picture feature. As with the timestamps, do not “burn in” colorbars and legends. Make sure to test the size and fonts of colorbars and legends on the sphere to ensure legibility. For more information on labels and colorbars, see the Dataset ManualText formatting of labels may also be fully customized in the SOS Visual Playlist Editor.

Captions

Captions can be displayed on SOS from standard SupRip Subtitle (SRT) files that are read in to SOS directly. An SRT file is an industry standard file that contains a sequential set of subtitles with their start and end timecodes.  Captions provide text for hard of hearing (the left image below) or non-English speaking audiences (the right image below) and can also be used to show movies in AutoRun with the sound muted.  Text formatting of captions may also be fully customized in the SOS Visual Playlist Editor.  The following example shows both captions (top text) and labels (bottom text) rendered onto a dataset:


File Names

Single images are typically named for their resolution, such as 4096.jpg. Image sequences are kept in folders that are named for their resolution, and the images themselves should be named to sort in ascending order from earliest to latest. This can either be done with a time stamp in the file name, or a frame number in the file name with a sufficient number of leading zeros in ensure proper sorting, shown in the example below. Videos should be named based on content and resolution, such as hurricanes_2048.mp4. By including the resolution in the file names, SOS users are able to easily determine what is available and appropriate for their system. Linux and the SOS software do not handle spaces and special characters in file names well. Do not use spaces and special characters in file names!

Named by Date
snow_ice_2048_20110730.png
snow_ice_2048_20110731.png
snow_ice_2048_20110801.png
snow_ice_2048_20110802.png
snow_ice_2048_20110803.png
snow_ice_2048_20110804.png
snow_ice_2048_20110805.png
snow_ice_2048_20110806.png
Named by Order              
sos_jpl_4096.0001.jpg 
sos_jpl_4096.0002.jpg 
sos_jpl_4096.0003.jpg 
sos_jpl_4096.0004.jpg
sos_jpl_4096.0005.jpg
sos_jpl_4096.0006.jpg 
sos_jpl_4096.0007.jpg
sos_jpl_4096.0008.jpg

Dataset Extras

Picture In a Picture

Picture in a Picture (PIP) allows you to display single pictures (any of the previously mentioned image formats works), an image sequence, or videos (MPEG4 only) on top of any dataset. This feature can be used to display any image, but is commonly used to display colorbars, charts and graphs, logos, and other images that supply supplemental information. Images that you are going to use as PIPs can be stored in the dataset folder that they go with.

When used for a colorbar, a PIP can help label a dataset, as seen at right. It is not recommended to embed colorbars or other supplement imagery into the maps that you create. Leave them as additional image files that can be added in the playlist.sos file. This gives the user complete control over the position and size of the PIP and gives presenters the ability to turn them off on the fly using the SOS Remote app.

A PIP can also be used to provide a close-up view of a region or give the viewer additional context for what they are seeing. In the example at right, the underlying dataset shows the tracks of elephant seals in red, and the PIP is a picture of actual elephant seals. Multiple PIPs can be shown at the same time, or staggered to create a slideshow effect. Make sure to consider the placement of the PIP in order to not block information in the underlying dataset, especially if the PIP is displayed for an extended period of time.

By using PIPs that are PNG’s with a transparent background, many different shapes can be projected on the sphere with the underlying dataset as a background. PIPs can be set to display in specific locations on the sphere as markers, as seen at right. Here each pushpin is a PIP that identifies the location of a SOS installation.

Standard PIPs shouldn’t be any larger than 1024x1024 in resolution size. Be aware that overlapping and warping can occur if the display size of a PIP is set too large. Make sure to test each dataset before distributing it to other sites, checking the PIP size, placement and timing. PIPs can also be MPEG4 files or image sequences.

Each PIP must be specified with the pip attribute. You can point to an image, time series, an image url (for example: http://example.com/image.jpg), or a live stream (for example: rame.sdp). All of the following modifying PIP attributes must then be listed below that PIP. To add another PIP, simply add another line that starts with pip and then list the modifying attributes in the lines below it. You can add as many PIPs as you want.

A Text PIP is a special kind of PIP that displays text only.  A Text PIP has all the same attribute specifications as a normal PIP, such as width, opacity, and fadein time.  Rather than using an image editing program to create text and save it as an image file for a PIP, you can use the SOS Visual Playlist Editor and enter text directly into the PIP Text Editor and save the Text PIP to your SOS dataset.  A Text PIP gets written to an html file.  You should only use the PIP Text Editor to create and edit Text PIP files, and you should not create or edit it by hand.  The following image shows an example of text in multiple languages that was easily created using Text PIPs:


Moving PIP: Each type of PIP (image, image directory, movie, text) can be given a simple path file that contains coordinate locations that indicate how to automatically move the PIP on the sphere as the dataset is animating.  The path file is a simple comma separated value file (.csv file format) that contains a list of increasing frame numbers, each with a latitude and longitude value.  As the dataset is animating, the PIP will be moved to the location specified in the file that corresponds to the current frame being displayed on SOS.  Option to render a line path that follows the moving PIP is provided and is turned ON by default. As an example, if one line in the csv file contains the entry 24,10,160, when the dataset's frame number reaches 24, the PIP will be displayed at a latitude of 10 and a longitude of 160.  The moving PIP feature makes it easy to show animal migrations (example below shows leatherback sea turtle track), hurricane tracks, etc. on SOS without having to render a moving object into the underlying global movie or image data.  Use the SOS Visual Playlist Editor's PIP Path Editor to associate a csv file with your PIP.


Annotation Icons

The SOS Remote app, through the annotation feature, gives presenters the ability to draw on the sphere and place icons on the sphere. There is a set of default icons that come with the SOS Remote app. In addition, sites have the ability to create custom icons. If you would like to create your own icons, use a transparent PNG with a minimum resolution of 256x256. To the right is an example of one of the default icons. Custom icons can either be specified for specific datasets, or made available in the default icon library.

Layers

The layering capability in SOS allows presenters to dynamically turn layers on and off. A multi-layer display can be created either statically in the dataset playlist beforehand, or interactively using the SOS Remote. By using the new Display Elements list in SOS Remote, the user can toggle individual layers on and off, adjust the level of transparency of each layer, or delete a layer. Any labels/captions or PIPs associated with a clip are now also listed individually in the Display Elements list. These can be interactively manipulated like any other layer.


Color Suggestions

A color scale can dramatically change the emphasis and message of a dataset. Because of this, the Science On a Sphere Users Collaborative Network has had many discussions on the color scales that are used for SOS datasets. The goal is to create datasets with well-chosen color scales that are meaningful, intuitive, and scientifically accurate. Several conclusions are the result of these discussions:

  • It can be confusing to users when the same color scheme and their associated color bars are used for two completely unrelated datasets.
  • The same color should not be used to represent more than one thing. i.e. if ice is shaded white then white should not also be used for areas of missing data.
  • Using rainbow-colored legends and color schemes is often confusing to the audience and hard to parse. Instead, consider using shades of green to represent phytoplankton, and blue and red gradations to represent temperature anomalies. i.e. use “meaningful” colors
  • Avoid using full sphere backgrounds that are completely or pre-dominantly white. The seams between projectors become more apparent when using solid white/bright backgrounds. f using bright background colors, consider adding some noise/texture to them. Same goes for PIPs, especially those displayed at the seams between projectors

Tools to Create Datasets

Because Science On a Sphere® uses common image and video formats, you can use many tools to create and edit datasets. Some of the common tools used are Photoshop, FinalCut Pro, ImageMagick, GIMP, etc. You can use whatever you have available and are comfortable using. A program like FinalCut Pro can be used to add transitions, special effects and other computer graphic techniques. At a higher level, tools like IDL, AWIPS, McIDAS, and other image analysis applications are typically used to create imagery from scientific datasets. As an example, we have used AWIPS (Advanced Weather Information Processing System) to create images from numerical forecast models. A graphics designer can use a 3D modeling application, such as 3D Studio, to create advanced visualizations for SOS.

QGIS Tutorial

GIS programs such as ArcGIS or Quantum GIS can be used to create maps. A tutorial for creating SOS datasets with Quantum GIS is available here: QGIS Tutorial.

Part 2 - Adding a Dataset

Parts of a Dataset

Every dataset that is added by the user to the SOS Data Catalog should be in its own individual folder in the directory /shared/sos/media/site-custom. Do not put your site-created content into the folders created by NOAA. Complementary or similar datasets can be grouped together in a folder that contains individual folders for each dataset. There are many content elements that can be used to create a dataset. For the NOAA-provided datasets you will find the following elements in each folder (not all of these elements are available for each dataset):

  • Image, Image Sequence, or Video - REQUIRED
  • Text file labeled playlist.sos - REQUIRED
  • Text file labeled labels.txt
  • Color bars and other supporting images
  • Media folder with thumbnails, videos, and supporting documents

In the above example of a NOAA provided dataset, there are three datasets that are related and all from the same source. To keep them together, a folder was created in the atmosphere directory called aerosol. In the aerosol folder, each dataset was given its own folder: sulfate, blackcarbon, and blackcarbon_and_sulfate. Notice that there are no spaces in the names! In each of the individual dataset folders there is an image sequence named for the resolution of the frames, a MPEG4 video, a media folder with thumbnails, a colorbar, labels, and a playlist.sos.

A playlist.sos Example

Every dataset folder must contain a file that is named “playlist.sos”.

Playlist.sos files can be generated by using the Visual Playlist Editor or using a text editor, such as Notepad or gedit. There can be multiple playlist.sos files in the same folder, such as playlist.sos and playlist_audio.sos, as long as they reference the same dataset. When working with multiple datasets, they should each be in their own folder with their own playlist.sos file, as shown in the aerosol example. No playlist.sos file should point to multiple datasets.

In this blue_marble example, there are two playlist.sos files in the folder for the blue_marble dataset, playlist.sos and playlist_audio.sos. Both playlists point to the same data, and the only difference is that one includes audio and a timer and the other doesn’t. Notice that the audio files have been put into their own folder. If there are multiple audio files or PIPs, a folder can be created in the dataset folder that contains those files. While this isn’t required, it helps to keep the folder uncluttered.

When files that are referenced in the playlist.sos file aren’t in the same directory as the playlist.sos, the path to the file needs to be included. Take note in the playlist_audio.sos file how the audio points to audio/BlueMarble.mp3 since the mp3 file isn’t in the same directory as the playlist.sos. Either relative paths (audio/BlueMarble.mp3) or full paths (/shared/sos/media/land/blue_marble/blue_marble/audio/BlueMarble.mp3) can be used in the playlist.sos files. Be careful to avoid typos, as the dataset won’t work if anything is wrong!

Notes about Site-Custom Datasets

There are many settings that can be included in the playlist.sos file. For a dataset added by a site into the site-custom folder, the playlist.sos file should contain the following elements:

name = My Custom Dataset
data = 4096.jpg
creator = My Museum
subcategory = land
keywords = land, Earth, My Museum
description = {{ A description for my dataset that will appear on the iPad. The description is allowed to span multiple lines and must use be enclosed with the braces characters. }}

The first two lines are required, and the remaining lines are all optional, but provide helpful information and allow you to more easily find your dataset. There is no need to add a category because all datasets in the site-custom folder are automatically tagged for the site-custom category. In order for a new dataset to show up in the site-custom library on the local SOS computer, make sure to update the library by clicking “Library” > “Update Library…” in the SOS Stream GUI. After you have updated the library, you have to click the “Update Now” button in the Settings tab of the iPad in order for it to show up on the iPad. It will not appear on the iPad if it is not stored in the site-custom folder on the computer. In the Data Catalog tab of the iPad you will be able to find the new dataset in the subcategory that you assigned under the site-custom main category. You can create as many different subcategories as you like within site-custom.

We have viewed many datasets and are happy to review your site-custom datasets and provide feedback as desired. Particularly for datasets that will be submitted for consideration for the SOS Catalog, we suggest providing a draft version to the SOS team for feedback.

Submitting a Dataset to the SOS Catalog

If you decide to submit a dataset for consideration to be part of the SOS catalog, we will need all the content pieces and the playlist.sos file, along with a written description of the dataset, a list of notable features, and the credits for the dataset. All of this documentation is used to create an entry in the SOS Dataset Catalog, as seen at right. The written description should be a simple overview of the dataset that highlights the source of the data, whether it is modeled or measured, what it shows, and why it’s important. It should be a non-technical description that is easily understood. The “Notable Features” is a bulleted summary of the highlights from the description that presenters can use when showing the dataset to viewers. The credits are used to fill in the column on the right-hand side. The credits listed are:

  • Dataset Source
  • Dataset Developer
  • Dataset Visualization Developer
  • Contact (optional)

These can be the same for each listing, or all different and can include links to the original sources. For examples, visit the SOS Dataset Catalog.

Presentation Playlists

If you are creating or using multiple datasets that you want to group together, then you'll need to create a presentation playlist. There are many different ways to create presentation playlists and you can read about them in the Presentation Manual.