Authoring

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WorldWide Telescope can be used to explore the universe but it can also be used to capture your exploration or create a structured presentation that you can share. These sharable experiences are called tours. The simplest type of tour uses Slides which is similar to PowerPoint. Slide-based tours are different in that they have a start and end position for the viewpoints as well as for objects like text and image. There are two ways you can get started to create a slide-based tour, either modifying an existing tour or building one from scratch.

You can open a tour that someone else has created and edit it. This allows you to see what others did to create the tour and make changes to it on your own. To find a tour to start with Click on the “Guided Tours” tab at the top of WorldWide Telescope. You will see a collection of Tours organized by categories, such as “Learning WWT,” “Nebula,” “Galaxies” etc.. Click into a category and you will see a representative image and title. As you mouse over the tour, a description and author will be shown. When you click on a tour, it is downloaded and when it is finished it will play on your computer. Note it will playback full-screen. If you are starting out, you probably want to watch the tour before you start to modify it. When it is finished you will be given a choice to close the tour or watch it again. Click “Watch Again” and then click the Pause button in the upper left of the window. Then click “Guided Tours/Edit Tour.” When a tour is in edit mode, you see controls to edit Tour Properties, Music, Text, Pictures etc. in the upper right as shown in the screenshot below.

Guided Tours Edit Tour

Another way to get started it so begin with a blank canvas. To do that select “Create New Tour” under the “Guided Tours” tab at the top. This will bring up a Tour Properties box. You must provide a Tour Title, but all other fields are optional.

Tour Properties
  1. Use WWT to setup the initial view for the Tour. Setup Look At Sky if you want to show images of the sky or Look At SolarSystem if you want to fly around the Solar System.
  2. Once you have the first “Add New Slide” at the top left of the WWT window. This will create an initial slide and choose a thumbnail image from the current view for it. It will also setup a default duration for the slide, which is 10 seconds. You can adjust this by clicking in the time field and with typing the time or using the little up and down arrows on either side of the time.
  3. It is helpful to have slides numbered automatically, so I usually select “Show Slide Numbers” from the “Guided Tours” menu. Note, this option is only available when you have a tour loaded. In addition to numbers it is useful to label slides by clicking the bottom of the slide thumbnail above the time field.
  4. You now have a slide with an initial view. You now should set an ending viewpoint for the slide. Throughout the duration of the slide (default is 10 seconds) the viewpoint will smoothly change between the beginning and ending camera positions. To set the end slide position, change the viewpoint (e.g., pan to another part of the sky, zoom-in etc.). Then right-click on the slide and select “Set End Camera Position.” Note, there is a yellow ear on the top left of the slide when you are looking at the start position and on the right hand part of the slide when looking at the end camera position.
  5. Now you have a 10-second tour consisting of one slide. Go ahead and press the Play button to see how it works.
  6. When showing the end camera position of the first slide, click “Add New Slide” again. This will add a second slide using the end camera position as the starting position for the new slide. If a sequence of slides is intended to show contiguous motion, you should make sure that the end camera position of one slide is the same as the beginning camera position of the next one.
  7. You can continue these steps to create a sequence of slides.
  8. Between every two slides there are various transition options, shown below. Note that some transitions take time which is taken out of the start time for the second slide (Slide B). Note that the transitions can be thought of as being added on top of camera motion defined by the slides. Transition Options
    1. The default arrow means that the slide moves from the end of one slide to the next without pause. This is used for contiguous motion.
    2. The A\B transition is a cross-fade between two viewpoints.
    3. The A|B transition is a hard cut between two viewpoints.
    4. The A\/B transition is one that fades through black between two viewpoints.
    5. The /B transition is a hard cut from A to black and then fades in B
    6. The A\ transition fades out to black and then does a hard cut to B.
  9. You can also add elements – Text, Shapes and Pictures – to slides.
    1. Clicking “Text” shows a text dialog box where you can enter text, select font and font-size, foreground color, background color, background options (e.g., tightness of box around text). The last menu option gives you the ability to add dynamic fields, such as Date, Time, Longitude, Latitude etc.
    2. You can add built-in shapes, such as circle, rectangle etc.
    3. Finally, you can add pictures.
    4. By default, all objects that are added stay in the same place on the screen throughout the slide. However, once added, you can right-click on an object and click “Animate.” This enables you to specify how the object should look at the beginning and also the end of the slide. Once an object is animated, you can right click on the slide and “Show Start Camera Position” and then change the location, size etc. of the object and the right-click and “Set Start Camera Position.” You can do this again for the end positions changing the end characteristics of animated objects. You can also turn off animation. It will default to whatever slide position is showing (Start or End).
  10. If you have a long tour it is time-consuming to watch the entire tour to see the effect of a change near the end. You can right-click in any slide and select “Preview Tour From Here” and the tour will play from that location, including audio.
  11. You can reorder the slides by clicking a slide and moving it to a new location in the slide set. You can select multiple slides by holding down Control while clicking on slides; selected slides will be outlines in yellow.
  12. When the tour is stopped but in Edit mode, you can move up and down through the sequence of slides using Alt+Page Up and Alt+Page Down keys.

There is special type of slide called a Master Slide. Overlay elements (Text, Shapes and Pictures) remain on all subsequent slides until another Maser Slide is encountered. You make a slide a Master slide by right-clicking and selecting “Master Slide.” This also affects audio. Audio on a master slide continues to play through subsequent slides until the tour hits another Master Slide.

When you are want to save the tour, you can click the Save button in the upper right or you can select “Save Tour As…” from the Guided Tours menu. This tour file (with the .wtt) can be shared with your friends and they can see your tour on their machine (assuming they have WorldWide Telescope installed).

Slide-based tours have only a start and end position and WWT smoothly moves between them. However, you may need finer control to change views, location and appearance of objects in a more flexible fashion. To do this, you can edit the timeline control for each slide of a tour.

Important: Tours containing timelines can only be played back on WWT 5.0 or later.


Create a tour using the Timeline Editor

To create a tour using timelines, do the following:

  1. Create a new tour - Guided Tours and then click Create a New Tour...
  2. Set Look At mode and the orient initial view for the Tour.
  3. Create an initial slide by clicking Add New Slide.
  4. Right-click on this slide and select Create Timeline. This will display a timeline window at the bottom of screen. The buttons outlined allow you to adjust the size of the window as well as unpin it from the main window.

screen shot of timeline editor buttonsThe WWT timeline

The timeline editor shows objects and settings on the left. Initially, there will be a single element on the left called Camera. The + symbol to the left will open a list of attributes you can control. There are transport controls which take you to the beginning or end of the timeline as well as playing forward or backward. The time is shown across the top of the remainder of the frame. Time is shown in MM:SS along with frame numbers – 30 frames per second. Objects can be controlled down to one frame = 1/30 of a second. While over the timeline you can use the scroll wheel on your mouse to change the scale of the timeline and to scroll the view of the timeline left and right. You can grab the yellow triangle which adjusts the current time. This is useful to get from one point to another and to see motion in the main window.

Note: The one aspect of the view that cannot currently be controlled by the timeline is the Look At mode. This must be set once for the entire slide.

Example:

For this example I will Look At SolarSystem. A one-slide tour showing this example is available here

Adding objects:You can right click and select Add to Timeline on most of the objects in the Layer Control Manager on the left hand side of the screen. For some planetarium productions, the constellations might need to be turned on at some point and then fade out. You can add separately control Constellation Pictures, Figures, Boundaries and Names. In this example, I will add constellation figures and planetary orbits, both with labels.

  1. In the Layer Manager, under Sky > Overlays > Constellations, make sure that the Constellation Figures is checked and then right-click and select Add to Timeline. This will create an object called ConstellationFigures in the timeline.
  2. Also in the Layer Manager, under Sky > 3d Solar System, make sure that the Planetary Orbits is checked and then right-click and select Add to Timeline. This will create an object called SolarSystemOrbits in the timeline.

You can also add overlay objects such as Text, Shapes or Pictures. For this example, I’ll create two Text Objects called Our Solar System and The Sky and put them at the same location. Then I will right-click and select Add to Timeline.

Hint: Sometimes you can’t see the overlay objects because then are stacked up, underneath a menu or difficult to find in Full Dome mode. In the Guided Tours menu select Show Overlay List. A list of text, shape and image overlays is shown. You can right click on overlay objects and change the ordering, color etc. If you are going to add something to the timeline with color, you should change the color in this right-click menu rather than the text entry box. You can change the name in the Overlay List by right clicking and selecting Properties. When using the timeline editor do not select Animation, which is a slide-based way of doing a similar as timeline editing.Sometimes you can’t see the overlay objects because then are stacked up, underneath a menu or difficult to find in Full Dome mode. In the Guided Tours menu select Show Overlay List. A list of text, shape and image overlays is shown. You can right click on overlay objects and change the ordering, color etc. If you are going to add something to the timeline with color, you should change the color in this right-click menu rather than the text entry box. You can change the name in the Overlay List by right clicking and selecting Properties. When using the timeline editor do not select Animation, which is a slide-based way of doing a similar as timeline editing.

Keyframes: Each object or setting in the timeline can change display attributes at specific times and WWT will smoothly move between them. These are called Keyframes and are represented in the timeline editor as small rectangles. Above the list, there is button to create (key) and delete (key with x over it) keyframes. Initially, there is a keyframe at the beginning of the timeline for every object that has been added to it.

In this example, start with a view of the sky with constellations, fade out the constellations and fade in planet orbits and end with a view of the Solar System. You can easily move keyframes in time, so start by considering the sequence and refine the timing later.

Start by expanding the timeline editor clicking the up arrow. First adjust the constellation figures to fade out from second 3 to second 5.

  1. Click the “+” symbols to the left of ConstellationFigures.
  2. Click on Opacity under ConstellationFigures.
  3. Move the time to 00:03.
  4. Click the Add Key button (looks like a key above the list).
  5. Move the time to 00:05.
  6. Make sure Opacity is still highlighted and click the Add Key button.
  7. Click the first key you made at 3 seconds. An editor box will show up. If a single key is selected then the label of the key will be shown above the field on the upper right. If key object is not expanded a keyframe will control all attributes. Note, the time field is also shown but you cannot change the time.

screenshot of keyframe propertiesKey Properties pop-up window

  1. Make sure the Opacity is set to 1.
  2. Edit the Opacity keyframe at time 00:05, and set it 0. Then close the window by clicking the X in the upper right.
  3. Do the same for the Opacity keyframe at time 00:00.
  4. Edit the Opacity keyframe at time 00:05, and check that it is 1.
  5. Do the same (steps 1–12) for the Color.Alpha attribute under the object entitled The Sky.
  6. Run the time scrubber back and fort hand you should see that at time 00:03-00:05 the constellations and text The Sky will fade out
  7. For the SolarSystemOrbits create keyframes at 00:03 and 00:05 the Opacity attributes to 0 at time 00:00 and time 00:03 and to 1 at 00:05.
  8. Repeat this for Color.Alpha for the text object Our Solar System.

Now when you play the tour (either with the play button in the timeline editor or the big play button to the left of the single slide of the tour), the tour plays, showing the sky rotating with constellation figures and text label The Sky shown. Then at 00:03-00:05 these elements fade out and the planetary orbits fade in with a text label Our Solar System.

Transition Functions: Keyframe editor can also allow you to select Transition Functions. These affect the way attribute changes between one keyframe and another. The transition of input and output values is shown graphically. You can select from the following choices.

  • Linear – Numbers are linear changes between values
  • Exponential – Changes are change faster at the begging and slow down at the end – similar to EaseIn below.
  • EaseIn – Changes are change rapidly at the begging and slowly at the end.
  • EaseOut – Changes are change slower at the begging and rapidly up at the end.
  • EaseInOut – Changes slowly at beginning, changes rapidly in the middle and slowly at the end.
  • Instant – Keeps starting value until the very end where it changes instantly to a new value.
  • Custom – Allows you to change the curve interactively. Grab the yellow square handle on each end of the curve which manipulates the beginning and ending shape of the transition curve.

It is good to choose a keyframe such as camera motion and try out all the transition functions to get a sense of what they can do.

Manipulating Keyframes in Timeline Editor

Besides changing the properties of keyframes, single or multiple keyframes can be selected for deletion, copying or pasting. Selected keys are shown as yellow. There are three ways of selecting keyframes:

  • Control-A – selects all keys in timeline.
  • Control-click – holding down the control key and clicking multiple keys adds them to a group.
  • Drag rectangle – dragging a rectangle around the keys of interested groups those keys.

Note: you cannot move the keyframes at time = 00:00 from that time, even if they are selected as part of a group.

In this example, I will move the keys from 03:00 to 04:00 to make a shorter transition. To do this,

  1. Show timeline editor and move it to show time 03:00 to 04:00.
  2. Drag a rectangle over the keys at 03:00. They should all turn from white to yellow.
  3. Move the selected group of keys to the right and place them at 04:00.

Adding Fade-In and Out for Slide

If you are comfortable with the timeline editor, it is better to use it to control slide Fade-In and Out. Controlling the Fade-In can be very helpful to hide data loading especially.

  1. Move the time slider in the timeline to the left. Find the Fade to black in the layer manager. Make sure the Fade Dome Only is not set. Check the Fade to black box.
  2. Right-click on Fade to black and select Add to Timeline.
  3. Move the time slide to 01:00. Uncheck the Fade to black box. Right-click on Fade to black and select Add keyframe.
  4. Move the time slider to 09:00. Right-click on Fade to black and select Add keyframe.
  5. Move the time slider to 10:00. Check the Fade to black box. Right-click on Fade to black and select Add keyframe.

Now when you play the slide in the timeline editor or tour player, it will fade in and out. Note that scrubbing by manually moving the time doesn’t trigger the fade to black.

Note: If you change the duration of a slide with an existing timeline, it will ask you if you want to trim/extend or scale the timeline. If you trim, be careful because you won’t have an end position for the slide. When trimming and the camera or other properties are changing, you probably want to move the time slider to just before the trim point. Then make key frames for the changing parameters. Then when you trim the timeline it retains keyframes of an end position for interpolating between values.

WorldWide Telescope can play back a separate stereo voice-over and music tracks to tell a narrative story and provide a music soundscape for a tour. Before starting to create audio you should decide which of two general strategies you want to follow. The first is to produce an entire audio file for the entire tour and the other is to create separate audio files that are tied to each slide. The advantage of creating a single audio file is that you can globally adjust the level for audio on all slides, and work on global timing. However, for narration you will have to acquire a long sequence in one go, or use an audio editor to cut out sections, replace flubs etc. Also, if audio is recorded as one long track and you change the timing of the visuals you have to re-record or re-edit the narration track.

For these reasons, the recommended way to do audio is to place the musical bed as a single soundtrack and to include narration audio on a per-slide basic. This how-to will show how to do this.

  1. Get at least a draft of your tour done visually. Word drive the visuals and visuals drive the audio. The visuals will provide an estimate of the tour length.
  2. Find an audio file that has the sound and length that fit your tour. More ambient music is more appropriate to loop and thus allows a shorter file to be used as a bed for a longer tour.
  3. Make a short first slide. I often make the tour and then duplicate the first slide and make the first of the duplicates a very short – 0.5 to 1.0 second – slide. Make this slide a Master and don’t have any – or a very small amount of – motion and don’t have any text or images. The reason we make a short Master is to separate audio that spans multiple slides from text and images that will be on only a slide or two. If you put these elements onto a Master slide they will persist until the next master slide.
  4. Add the audio to the slide buy clicking on Browse under Music in the upper right hand of the WWT window. Browse to the music file. You can enter a Fade In and Fade Out times for the music and setting it to automatically repeat or not. Adjust the slider to be 1/2 to 2/3 the way to maximum. Since this is a Master slide, the music will play over all slides until the tour hits a music track on another Master slide.
  5. You can add music tracks on a per-slide basis which will be mixed into the musical bed of the master slide. This might be useful if you wanted to coordinate a sound effect coordinated with a visual on one slide.
  6. Assuming you have a script, which may or may not be displayed as text on each slide, you know what words to say for each slide. Record a voiceover file (e.g., MP3) for each slide. It is worthwhile to label the slides with text and use the automatic slide numbering (check Guided Tours/Show Slide Numbers) for the slides and use a similar naming for the narration audio files. When recording try to use a quiet room without hard surfaces (i.e., carpet, drapes and objects in the room are good and fans air conditioners etc. are bad). It is useful to normalize the voiceovers in their uncompressed form before compressing to MP3. Tips on getting great audio are in another how-to (Editing Audio). You want to make sure that the slide is at least as long as the narration audio. Add the audio by clicking Browse for Voiceover which is just below the Music selector.
  7. You can preview the tour from that slide and adjust the level of the narration relative to the music. When in doubt it is more important to be able to hear the voiceover than the music.

In the Dealing with Audio how-to, we show how to get audio tracks into WWT. This guide will give some tips on how to create and edit the audio that you want to include in your tour. WWT can play a variety of audio files. Playback quality it limited to the quality of the input audio file so start with the highest quality. If you are getting an existing file or if you are creating your own try to get a lossless format, like WAV, or a high-bitrate one, like 320 kbps MP3.

I will illustrate how to edit audio using an open source windows program called Audacity (http://audacity.sourceforge.net/), however most audio editing software can probably do the same things.

I edit software for the following purposes: trimming, normalization, background noise removal and format conversion. I would do all editing in WAV and then convert to MP3 at the last step. Also, I would use draft audio until you have finalized the visual timing and then do audio editing and conversion.

Trimming

When you get music of narration files often the timing of the files needs to be adjusted. When you know the timing of the tour you are trying to match and the audio file you may need to cut some off of the audio file. Cutting the length for the file can make is smaller and you can also add custom fades (in and out) at this point.

Figure out the time you want to trim to and if you want to add a fade in or fade out. For this example I will put a 2 second fade out at the end of a musical audio file. Since the music builds gradually, I will not change the beginning of that with a fade-in.

  1. Open Audacity and load input audio file. Identify the length you want the audio piece to be.
  2. Use mouse to select 2 seconds from the end.
  3. Click “Effect” in the top menu and select “Fade Out.” This will create a linear fade out that you can see graph in Audacity.
  4. Select from the beginning to the end of the ending fade.
  5. Click “File” in menu and “Export Selection.”
  6. Choose WAV -- assuming you will save this uncompressed WAV file as an archive and convert to MP3 in another step (see below).

Normalization

Audio is inherently analog and capturing a digital copy requires you to sample it into a range of digital values. Digitized signals have specific steps between each level. In order to have the best sounding signal it should be normalized such that the maximum signal is at the highest value of the digital signal. This has the effect of making the signal as loud as it can be without clipping. Then you can reduce the volume with the slider in WWT.

  1. Open Audacity and load input audio file. Identify the length you want the audio piece to be.
  2. Use mouse to select the entire file (or the part you want to export and use).
  3. Click “Effect” in the top menu and select “Normalize.” This will bring up a dialog box. I check all boxes and set the maximum amplitude to 0.0 dB. This will scan the file and determine the scaling to amplify the signal to the maximum values.
  4. Select from entire file of a selection.
  5. Click “File” in menu and “Export Selection.”
  6. Choose WAV -- assuming you will save this uncompressed WAV file as an archive and convert to MP3 in another step (see below).

Background Noise Removal

  1. Open Audacity and load input audio file.
  2. Put cursor in file window and select a part of the audio file where there is noise. You may want to expand the range to see this clearly.
  3. Click “Effect” in the top menu and select “Noise Removal…” This will bring up a dialog box. Click “Get Profile.”
  4. Then select the entire audio file (or the part you want to save out).
  5. Click “Effect” in the top menu and select “Noise Removal…” This will bring up a dialog box. I leave the default values and then make sure “Remove” is selected and click the “OK” button.
  6. Click “File” in menu and “Export Selection.”
  7. Choose WAV -- assuming you will save this uncompressed WAV file as an archive and convert to MP3 in another step (see below).

Format Conversion

If you are getting music files, WAV files are great for quality, but can be large. Note, that tours encapsulate assets like audio and images so be aware that file sizes could be large if you include uncompressed audio like WAV. I suggest working with WAV files and keeping copies of those around for editing, but before putting the files into WWT, converting it to compressed MP3. Audacity can read in almost any format file and you can select the same file for export to another format.

  1. Open Audacity and load input audio file.
  2. Put cursor in file window and Control-A (select all).
  3. Under “File” click “Export Selection.”
  4. In the dialog box that comes up, select “MP 3 Files” as output format.
  5. Click the “Options” button which opens a box to select MP3 output encoding options. I use Variable Bit Rate, Quality level 5, 110-150 kbps. You can also use Constant Bit Rate with 128 kbps or higher.
  6. Load the file into WWT and play it back to make sure it sounds ok. If you are in a very quiet room with good acoustics and speakers you might hear MP3 compression and want to use a higher bit rate. Note that variable bit rate MP3 use file space a bit more efficiently and plays fine in WWT.

When making tours for Virtual Reality (VR), it helps to come up with certain rules about how the user interacts with the virtual environment and then stick to them. This helps to make tours that don’t provide visual information that is in conflict with other sensory input such as head orientation, which is provided by your inner ear. This disparity between what you feel in the physical environment (like turning your head) and what you see in the virtual environment can create symptoms similar to motion sickness.

One of the amazing things about VR is that users have a natural sense of interaction by moving their heads that requires no training. For instance the Impacts Tour has been shown to kids in Kindergarten, to seniors and all folks in between – all of them interacted with the experience without any specific instruction – with the exception that people do need to be reminded to look in some direction other than forward.

In WWT there are two different types of VR experiences. One experience is a more formal Virtual Reality experience. The other type we call Divine Visualization.

Creating Virtual Reality Experiences

Virtual Reality Experiences are constrained by rules; when these rules are followed, they support the presence of the user in the virtual environment and natural appreciation of scale and distance. Below are rules that we follow when making VR tours.

  1. Throughout a scene keep the same camera view. Don’t zoom your camera as you navigate a scene. That would be equivalent to scaling you to be bigger and smaller as you explore an environment. When you zoom the camera you change the stereo separation which confuses the sense of scale brain interprets through motion.
  2. In the tour only control the XYZ translations. The user will naturally control rotation by moving their head, which is then coordinated with the physical input that the inner ear gives the brain.
  3. Think about the user as a participant in the scene and actually decide what is the representation of the user is in the virtual environment – the user’s avatar. Even if the avatar is not visually displayed it will have specific capability (e.g., size, stereo separation of eyes, speed etc.). For instance, if the user is an astronaut with a jet pack that responds to a thruster then the translations should be of that speed.
  4. Be very careful about giving the user too much control. People thing they want to have as much control as possible, but if they don’t interact well with the environment, they can leave the system completely or be looking the wrong direction. Worse they can induce virtual reality sickness by quickly moving their view with the joystick in a way that is in conflict with their head’s motion. Training can help mitigate these effects but takes time and a carefully planned training experience.

In VR you can keep the zoom level constant and move the camera through a scene by reference frame for the camera and move that.

Creating Divine Visualization Experiences

Divine Visualization is a category of experiences where the producer breaks the rules of VR in order to tell a story or explore data. In this view, the user is not limited by rules of interaction of an avatar with a virtual environment, as is the case for creating strict VR experiences above. One simple example is moving the view of the Solar System from edge-on to face on. Here the divine viewpoint, which is not constrained by the laws of physics, is understood by the user as viewing and potentially manipulating the Solar System as a model or scientific visualization. As a producer, you may feel this is necessary to communicate some things this way. The user will probably not feel as though they are moving wildly in the Solar System but will likely interpret this as playing with a 3D model in a classroom.

visualization visualization

When you decide to break the rules, you can do anything you want. However, you should be aware of dissonance between visual and inner-ear-provided orientations and try to minimize them.

  1. Keep objects in front of the user while you are moving or changing them (e.g. rapid, non-linear advances in time). This will reinforce the feeling that the user is manipulating an object.
  2. Don’t introduce motions that would require the user to turn their head very much. This will reduce the amount of dissonance.
  3. Be very careful in creating interactive VR experiences where the user can use an Xbox controller to fly around a scene. Even experienced VR producers can get sick doing this. If you are designing an unconstrained interactive, we recommend some training phase of the interactive where they are taught how to move their view slowly, especially in rotation.
The Story

It is very important to start with the story. Tours naturally lend themselves to fairly strict VR experiences and many WWT stories involve moving the user through space and telling them what the objects are that they are seeing. This is the basic structure of the Impacts tour. In the Impacts tour, we were in this VR experience mode until the last two slides where we switched to Divine Visualization where we showed the Solar System in an unrealistic way. Tilting the view of the Solar System and even visualizing asteroids and orbit lines break the illusion of what someone would actually see. In Impacts we transition from one form to another, but don’t go back and forth in the Tour.

We created Impacts to test out the production features of WWT as well as learn about VR production. You can follow your own production experiences but certainly give adequate time for testing and refinement. Our experience is that when you are in VR during production, you get your VR-legs and will be able to handle more extreme motions and dissonance. That is why it is important to have people who are not familiar with VR to test out your experience. Carefully consider their input of how they interpret the experience and any susceptibility they have to motion sickness.

WorldWide Telescope 5.0 has specific functionality to enable dome authoring and playback. Technically, tours created on/for a flat display, such as a laptop, will work on the dome. However, differences in the projection and the field of view create challenges to creating content on a flat screen and having it look good in a dome. This guide will go over some function in WWT that help move between these two views.

The main window view can be changed to preview a full dome view. To go into a dome view, under the View tab, select "Full Dome/Full Dome."

Note: The default full dome view has a wide hemispherical view of 180 degrees. In the flat projection the default view is about 60 x 34 degrees. Where this sub-region of the full dome view is located on the dome is controlled by the dome tilt. At 90 degree dome tilt, this view will be at the Zenith and at 0 degree dome tilt it will be near the bottom of the full dome image in the front.

full dome

Authoring on Single-Projector Systems

For systems with a single fish-eye or mirror-dome projector attached to a separate video output on the Master Server - which is probably the only computer, under the View tab, you can select “Full Dome/Detach Main View to Second [or Third] Monitor.” This will allow full-dome authoring playback on the same system. Menu and interface windows stay on the first monitor and the second or third monitor outputs drives the single full-dome projector. In this case, text positions are placed in the dome view and seen in the same way it will be viewed in a show, which facilitates the placement of their placement, as well as the pacing of motion, etc..

To setup the dome parameters, select View/Full Dome/Dome Setup, which opens a setup window.

setup full dome

Under Dome Type, you can select “FishEye,” “Mirrordome 16:9” or “Mirrordome 4:3.” You can also set the Dome Tilt. Multiple projector, or non-standard projections can be implemented by solving for projector geometries using “Settings/Advanced/Multi-Channel Calibration.” Details of this are given in a separate document.

If you have a single Projector Server which is different from the Master, the dome setup is the same but you will need to setup a simple 2-computer cluster, which is described in the WWT Multi-Channel Setup document.

Authoring on Flat Displays for Presentation on Dome

For the remainder of this document, I will assume you are authoring on a flat screen and will be playing back on another full-dome system, which could potentially be multi-channel. WWT has specific tools to facilitate this.

In the full-dome view the size and location of overlay objects like text, shapes and images makes it hard to see them when the hemisphere is projected back onto a flat screen as a full dome preview. Usually in the flat screen you just click on overlay objects in the main view. However, it is sometimes hard to see the overlaid objects in full dome preview on a flat screen. Note, that even if you can see the objects it is hard to actually select one to move, edit, etc..

Full Dome Mode

On a desktop you can view the full dome view in the main window by selecting View/Full Dome/Full Dome. This will change the main view into a hemisphere projected onto a flat display with black area around it.

full dome view

Overlay List

To interact with overlay objects (Text, Shapes & Pictures) in dome mode it is easier to use the Overlay List window, which is accessed under Guided Tours/Show Overlay List. The overlay objects have names that default to file names for imported pictures or the first line of text for text object. Shapes are named by their name followed by a number (e.g., “Donut 1”). You can always rename any overlay object by right-clicking and opening the Properties dialog.

Overlay List

Right-clicking on any of the images brings up a menu. Most options are the same is if you right clicked on the object in the main view. You also have an “Edit” option which is the same as double-clicking the overlay object in the main view. The Overlay List can make objects accessible when they are hard to click on in dome mode or off-screen or hidden under menu tabs.

Dome Preview

You can view a flat projection of a part of the full dome view using the Dome Preview. Since this is a flat projection you must make sure you are not in full dome mode. Make sure that View/Full Dome/Full Dome is unchecked. At this point you are viewing a virtual camera view of the full dome view. You can move the camera to see in detail what is being shown on any part of the dome with the Dome Preview window, which is shown by selecting View/Full Dome/Full Dome Preview.

dome preview

As you click your mouse and move it in the grey circle in the Dome Preview the main window will show a smaller tangent view of the full dome view. The preview is centered on the Alt/Az positions shown in the lower left hand corner of the Dome Preview window which changes are you click and move your mouse.

You can use WWT to create still frames, which can be encoded into a video. Note, that WWT writes out a sequence of frames and does not do the encoding to video. You will have to use another solution to create the video and include any audio. Some suggestions are given below. Rendering out of WWT might be desired in the following situations:

  • You have a planetarium with its own video playback system.
  • You want to combine WWT images and videos with other content. For instance, this could be done to use WWT to render out a star field at a certain time and then composite a horizon or other elements in front of it. Or you might want to render some scenes in WWT and other ones in another package and then splice them together.
  • You want to distribute a video to YouTube or create a video for a presentation in PowerPoint.
Simple Case

In the case of a flat screen, things are pretty straight forward. Once a tour your want to render out is loaded, select Guided Tours/Render to Video. This will open the Render Tour to Video dialog box.

Video output

By default the frames are written to “VideoFrames” folder under your “Documents.” In the dialog box, you just need to specify a filename. WWT will create a sequence of frames based on that name. If you give the name “C:\Users\Doug\Documents\VideoFrames\Rainforest.png” in the dialog box, WWT will write a sequence of images named Rainforest_0000.png, Rainforest_0001.png, etc. You should also leave the output extension as PNG. Don’t change it to anything else or give the name without an extension. WWT only writes PNG files.

Also, currently for flat (i.e., non-dome) output format is set to the same resolution as the display, so if you are on a 1080x1920 display that will be the output size of the PNG images. For flat screens, don’t change these numbers and WWT only renders out 30 frames per second (FPS).

The Run Time and Total Frames are reported from the Tour. You can adjust the Start Frame number to begin rendering frames to some point into the Tour. This can be useful when you want to render frames in sections or make a change to a part of the tour and render those frames out. Note, there is no way to specify the end frame here, so you will have to watch the progress dialog that reports how much has been rendered and then click Cancel when you want to stop it.

When rendering, we recommend checking the box Wait for all downloads, which will force WWT to wait to load any data, tiled images, 3D terrain, 3D cities needed to render each frame. Unless you just want to make a quick small pre-visualization, the additional amount of time to wait for all data to download is a small price to pay for better rendered output.

Dome

To render frames for dome output you have to do the following:

Dome Video output

  1. Make sure you are in Dome view. Select this under View/Full Dome/Full Dome.
  2. Open the Render Tour to Video dialog box.
  3. Check the Dome Master check box.
  4. Check the Wait for all downloads check box.
  5. In the Output Format pull-down, select one of the Dome Master formats: 1k, 2k, 3k, 4k, or 8k.
  6. Click Render to write the files.

Note that for large 4k or 8k images, writing each frame may take several seconds.

Making Video from Rendered Frames

Once you have your frames rendered you can make the output into a video. This functionality is not built into WorldWide Telescope, but here are some options of how to proceed.

First make sure the frames look ok and that the frame numbers are contiguous. Be careful if you render parts and try to put them together. If you do that we recommend that you render each part to its own folder and then copy the frames you want into a final folder.

If you want to add audio, you can use the voiceover and music audio files from the tour. Note, that you can include a sequence of audio files associated with each slide, but it may be easier if you combine those files outside the video encoding program and bring in just one audio file for voiceover and one for music.

QuickTime Pro ($29.99 from Apple) is a relatively inexpensive way to encode the sequence of PNG files into a video.

  1. Open the PNG images by selecting File/Open Image Sequence… Browse to the name of the first file of the sequence. This will open the sequence in its own window.
  2. In that new window, select File/Export, which will bring up a dialog box.
  3. Set the output video file name and options in this box and then click Save.

Adobe Premiere is a more powerful way to encode video.

  1. Open the PNG images by selecting File/Import and then browsing to the name of the first file of the sequence. Check the Image Sequence box above the file name and click Open.
  2. In a similar way you can import your audio tracks as well.
  3. You will see your image sequence and audio if you imported that in the media browser in the lower left panel. Drag the image sequence and audio files into the timeline in the lower right.
  4. To output the video, select File/Export/Media…. You can change any of the export controls in the dialog box and when you are happy click the Export button.

International Space Station

With the latest release of WorldWide Telescope, version 5, the International Space Station (ISS) is included in WorldWide Telescope!

  • Open up the Layer Manager (click View, Show Layer Manager)
  • Open Earth node, then ISS node and click on ISS Model
    • The first time you do this, WWT will silently download the model so it may take a little while to show up depending on your internet connection. WWT Layers
  • Right click on the ISS Reference Frame (not the ISS Model) and click Track this Frame
    • If the ISS model has completed downloading, you should see the model in orbit around Earth (pan around a little if you don’t see it right away). ISS Model
  • Try turning on Observing Time (View button) and you’ll see the space station orbiting in its actual orbit around Earth!

(ISS Model Credit: Toshiyuki Takahei)

3D Models

Several 3D Models have been made available on the WorldWide Telescope website. These 3D Models are embedded in WWT Layer files; where possible, the models have placed in realistic locations in relevant positions and orientations; accurate orbits have been created for relevant models.

To load and view a 3D Model:

  • Navigate to http://www.worldwidetelescope.org/Download/TourAssets.
  • Select the 3D Model you’d like to view (for example, Corot)
  • Click on the Corot link which will download the Corot Model in a WWT Layer
  • Open the Corot Layer File (either by double clicking on the file or clicking Explore – Open – Layer)
    • The 3D Model will be loaded in the Reference Frame in which it was saved
  • WWT Layers
  • If the Layer Manager is not already open, ensure it is opened (View – Show Layer Manager)
  • Navigate through the Layer Manager to see the Reference Frame (for Corot: Earth – Corot)
  • Right click on Corot Reference Frame and click Track this Frame
    • WWT will jump to the Corot 3D Model

Try turning on Observing Time (View button) and you’ll see Corot orbiting in its actual orbit around Earth!

You can also add your own 3D Models (OBJ and 3DS formats) into WWT using the Layer Manager.

This tour segment shows how to zoom out from the Earth and see a face-on view of the Solar System with planetary orbits. Then time is run forward with a time indicator and at an end time we zoom back to another location on the Earth. This segment can be used to show the passage of time probably with a timescale of one or more years.

  1. Make sure that you are in 3D Solar System mode. Also, since later on we want to illustrate the passage of time using the motion of the planets – and especially the Earth – make sure that in the Layer Manager, under Earth that “Planetary Obits” is checked.
  2. First start by setting the start time. Open view tab and enter the date and time in the Observing Time.
  3. Finding a location on the Earth where you want to start from and end at. In this example, I am starting at a hospital in Mountain View California. Note that depending on the time you selected above the location may be in darkness; if so you will have to change time such that it is in light.
  4. Set this as the beginning location of Slide 1.
  5. Zoom out using the mouse. When you are close to the ground, you probably want to limit the changes in camera to zooms and not any rotations or else the ground will move wildly when you are zooming out. In this example, I will just do a zoom out to a view of the Earth with no translation or rotation.
  6. Set this view as end location of Slide 1.
  7. Make a new slide – Slide 2.
  8. Adjust the final orientation of the Solar System such that the Earth is directly above the Sun. I use a tool called A Ruler for Windows to put a visual guide on the screen that I can use to make sure the alignment is correct as well as maintain scales. For reference I often take a screen shot of the view with the Solar System centered on the Earth before the next step. Use the ruler to measure the distance between the Earth and the Sun. You can click in the tick-mark area of the ruler and it will put a mark and numeric label at that location.
  9. Set this as the end location of Slide 2.
  10. Add new slide (Slide 3).
  11. Select (double-click) the Sun from the context menu on the bottom of the page. This will zoom into a close-up view of the Sun. Pull back out and get a face-on view of the Solar System. Align it such that the Earth is directly above the Sun and that the distance between the Earth and the Sun is what it was in the Earth-centered view.
  12. Set this as the end position of Slide 3.
  13. Add new slide (Slide 4).
  14. Add a text object and from the “Insert Field” menu – the right most menu item of the Text Editor window – select “Date.” Save the object and move it to a blank location on the screen.
  15. Click on the View tab and advance time to the desired date. This makes sense if it shows the motions of the planets, so this should be more like years than days.
  16. Set this as the end position of Slide 4.
  1. Go into Earth Mode (not Solar System).
  2. Search for Earth-based location, suggest “Yosemite Valley.”
  3. Right-click on Earth in Layer Manager and select “Add Reference Frame.”
  4. Enter name for reference frame, enter “Yosemite Valley.”
  5. Take defaults but change altitude of 1,000 meters.
  6. Go into 3D Solar System mode.
  7. Target Earth by double-clicking in it in the Context Menu at the bottom.
  8. Under Earth, right click on “Yosemite Valley” and “Track this Reference Frame.”
  9. If the altitude is not correct – maybe you want to be higher to hover and look down or lower to see the view from the ground – right-click on new “Yosemite Valley” reference frame and select Properties. In the Position Tab you can make changes to the altitude, which are reflected in the view when you click “Done.”
  10. Change Observing Time under view to show daylight changes. Turn to face east and get the time to go past sunrise to see the stars go away and blue sky come out.
  11. Note that this requires atmospheric effects and lighting are enabled.
    1. Atmospherics: In the Layer Manager under “Sun/Earth/Overlays” that “Clouds & Atmosphere” is checked.
    2. Lighting: In the Layer Manager under “Sky/3d Solar System” that “Lighting and Shadows” is checked.
sunrise sunset

In visual storytelling, sometimes you want to show a time-varying path from one point on a globe to another—think of the flight paths in the movies, Raiders of the Lost Ark or The Amazing Race. WorldWide Telescope makes this easy to do. In this documentation, we will add an expanding great circle from Chicago to Hawaii.

First, download the tour, Chicago-Hawaii Great Circle Route.

  1. Download Chicago-Hawaii Great Circle Route.wtt
  2. Open WorldWide Telescope
  3. Click Explore and select Open, and then Tour
  4. Navigate to the Chicago-Hawaii Great Circle Route.wtt file on your computer and click Open
    (Note that double-clicking this Tour directly from the file system will autoplay the Tour)

This opens the example tour. You should now see the Chicago-Hawaii Great Circle Route tour the top menu bar of WWT. Play this tour to get an visual example of how this functionality works.

To create a Great Circle Route:

  1. Go into Earth mode.
  2. In the Search/Find Earth Based Location… enter Chicago, IL. This will orient the view to center and zoom in on Chicago.
    Screen shot of location search
  3. Open the Layer Manager, right-click Sun/Earth, and select New Great Circle Route.
    screen shot of right-clicking earth in layer manager and choosing New Great Circle
  4. The top Lat/Lng coordinates are the start of the route and the bottom coordinates are the end position. Since you are already centered on Chicago, which is our starting location, click top << Get From View button, and then click Ok.
    screen shot of great circle properties dialog
  5. This will create an object entitled Great Circle Route. Right-click it and select Rename and give it a more descriptive title: Chicago-Hawaii Great Circle.
  6. Next, set the end location. Open Search/Find Earth Based Location… and enter Mauna Kea, HI. This will center your view on the big island of Hawaii and zoom into the top of the large volcano, Mauna Kea, where some of the world’s most powerful telescopes are located.
  7. Right-click Chicago-Hawaii Great Circle and select properties. To enter Hawaii as the end position, click << Get From View next to the lower Lat/Lng position.
  8. Zoom out to see the entire Great Circle.
    screen shot of earth with line from chicago to hawaii

To make a slide that starts in Chicago rotates the Earth as the circle extends in time, make a new tour

  1. Click Explore/ > New > Slide-Based Tour… Give it a title, Chicago-Hawaii Great Circle Route.

A tour can display the great circle route in either Solar System mode viewing Earth or in the Earth mode. For this example, we will be in Solar System mode viewing Earth.

  1. Center your view on Chicago and then in the slide editor panel at the top, click Add New Slide.
  2. Right-click the Chicago-Hawaii Great Circle object under Sun/Earth in the Layer Manager, and select properties. Change the Percentage field to 2. The view should still be centered on Chicago.
  3. Right-click the slide and then select Set Start Camera Position.
  4. Move the view to Hawaii. Perhaps you might zoom in slightly.
  5. Edit the properties of the Chicago-Hawaii Great Circle object again. Change the Percentage field to 100. The view should still be centered on Chicago.
  6. Right-click the slide and then select Set End Camera Position.
  7. Press the Play button, which should start the view in Chicago and then rotate the Earth from Chicago to Hawaii. The path extends with the rotation.