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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.

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 start and end positions; WorldWide Telescope (WWT) smoothly moves between these positions. However, the Timeline Editor gives you greater control over changing the views, location, and appearance of objects in a tour. Each slide of a tour can have its own timeline control.

Important: Tours containing timelines can only be played back on WWT 5.0 or later. When you first add a timeline, you will see a warning to this effect.

Create a tour using the Timeline Editor

To create a new tour that uses the TimeLine Editor, do the following:

  1. Create a new tour: select Guided Tours and then click Create a New Tour...
  2. From the Look At drop-down in lower left of the screen, make a selection and the orient initial view for your Tour.
  3. Create an initial slide: click Add New Slide at upper left of screen.
  4. Right-click the thumbnail of this slide and select Create Timeline. This will display a timeline at the bottom of screen.

In the image of the timeline below, the buttons outlined in green 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, you will see a single element on the left called Camera. Click the "+" symbol to the left of Camera to display a list of attributes you can control.

The blue transport controls in the lower left allow you jump to the beginning or end of the timeline, play the tour forward or backward, and pause the tour. You can also navigate through your timeline by dragging the yellow triangle (the “time scrubber”), which points to the current location in the timeline.

The time is displayed across the top of the timeline in MM:SS. Each second is divided into 30 frames per second giving you precise control up to 1/30 second. To change your view of the timeline, hover the mouse over the numeric labels of the timeline and scroll to increase or decrease the scale.

Note

  • The Timeline Editor cannot currently control the Look At mode. This must be set once for the entire slide.
  • If you change the duration of a slide within an existing timeline, a dialog box appear, asking you if you want to trim/extend or scale the timeline.

Example: Sky & Solar System Timeline

To demonstrate the capabilities of the Timeline Editor, we will use an example tour, Sky & Solar System Timeline.

  1. Download Sky and Solar System Timeline.wtt
  2. Open WorldWide Telescope
  3. Click Explore and select Open, and then Tour
  4. Navigate to the Sky & Solar System Timeline.wtt file on your computer and click Open

This opens the example tour. You should now see the Sky & Solar System tour the top menu bar of WWT.

  1. Right-click the first slide in the tour and select Show Timeline.

Adding objects

You can right-click and select Add to Timeline many of the objects in the Layer Manager on the left side of the screen. For some productions, you may need to turn on the constellations at some point and then fade them out at another point. You can add and separately control constellation pictures, figures, boundaries, and labels. In this example, we 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 checkbox is selected and then right-click and select Add to Timeline. This will create an object called ConstellationFigures in the timeline.
  2. In the Layer Manager, under Sky > 3d Solar System, make sure that the Planetary Orbits checkbox is selected 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 by clicking the Text, Shapes, and Picture buttons in the upper-right of the WWT window. Once you have created the overlay object, right-click it in the main window and select Add to Timeline. For this example, we’ll create two text objects named “Our Solar System” and “The Sky” and put them at the same location. Then we will add them to the timeline.

  1. Click the Text button to open the Text Editor
  2. Type “The Sky” and click Save
  3. Select the text object in the main window and move it to where you would like it to appear.
  4. Click the Text button top open the Text Editor again
  5. Type “Our Solar System” and click Save
  6. Select the text object in the main window and move it directly over the text “The Sky”. You can use the left, right, up, and down arrows to get text object precisely over the text, “The Sky.”
  7. Position the time scrubber at 00:00
  8. Right click The Sky text object and select Add to timeline
  9. Position the time scrubber at 00:03
  10. Right click Our Solar System 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 drop-down 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, and so forth. You can change the name in the Overlay List by right-clicking and selecting Properties. When using the Timeline Editor, do not select Animation; this is a slide-based method for editing the timeline.

Keyframes

Each object or setting in the timeline can change display attributes at specific times, and WWT will move smoothly between them. These are called keyframes and are represented in the Timeline Editor as small rectangles. Above the list of key objects, there is a button to create keyframes (the Add Key button) and to delete keyframes (the Delete Key button). Initially, a keyframe displays at the beginning of the timeline for every object in the timeline.

The Add Key and Delete Key buttons The Add Key and Delete Key buttons

Fading in and fading out

We start with a view of the sky with constellations and the text, “The Sky,” then fade out the constellations and fade in planet orbits and the text, “Our Solar System,” and then end with a view of the Solar System. You can move keyframes in time easily, so start by considering the sequence and refine the timing later.

We start by expanding the Timeline Editor by clicking the up arrow at the top of the timeline. First, we adjust the constellation figures to fade out from 00:03 to 00:05.

  1. In Layer Manager, click the “+” symbols to under Sky to reveal Overlays > Constellations > Constellation Figures.
  2. Right-click Constellation Figures and select Add to Timeline.
  3. In the list of key objects to the left of your timeline, click the “+” symbol to expand the list of ConstellationFigures, and click Opacity.
  4. Move the timeline scrubber to 00:03.
  5. Click the Add Key button, located above the list of objects on the left of the timeline.
  6. Move the timeline scrubber to 00:05.
  7. Make sure Opacity is still highlighted and click the Add Key button.
  8. Click the first key you made at 00:04 to display the Key Properties pop-up window. If a single key is selected, then the label of the key will be displayed above the field on the upper right. If a key object (such as ConstellationFigures) is not expanded, the Key Properties pop-up will control all attributes. Note that 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 typing 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 forth: you should see the constellations and text The Sky fade out from 00:03 to 00:05.

For the SolarSystemOrbits object, keyframes have been created at 00:03 and 00:05. The Opacity attribute is set to 0 at 00:00 and 00:03 and to 1 at 00:05. The same has been done with the Color.Alpha attribute for the text object Our Solar System. Run the time scrubber over the timeline to see how the solar system and the text “Our Solar System” fade in between 00:03 and 00:05.

 

Transition Functions: The Timeline Editor can also allow you to select Transition Functions. These affect the way attributes change 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 occur more rapidly at the beginning and slow down at the end—similar to EaseIn below.
  • EaseIn: changes occur rapidly at the beginning and slowly at the end.
  • EaseOut: changes occur more slowly at the beginning and rapidly at the end.
  • EaseInOut: changes occur slowly at beginning, rapidly in the middle, and slowly at the end.
  • Instant: retains 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 to manipulate the beginning and ending shape of the transition curve.

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

To set up a Transition Function:

  1. Open the Camera by pressing the + next to it (it may already be open)
  2. Click on any of the Camera Key properties by clicking one of the squares in the Timeline Editor
  3. Select a Transition Function other than Linear and test the effects of this by using the Time scrubber

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 to select keyframes:

  • Control-A: selects all keys in timeline.
  • Control-click: hold down the Ctrl key and click multiple keys to add them to a group.
  • Drag rectangle: clicking and dragging a selection rectangle around several keys to select them.

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

Moving keys to make a shorter transition

In our last task, we will move the keys from 03:00 to 04:00 to make a shorter transition. To do this,

  1. Reveal the Timeline Editor and move it to display 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.

Now play the tour and see how the transition time has changed.

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.

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 (OBH 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.