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Welcome to Layerscape Session A Generating Data in WWT, creating a Tour (story), and publishing at

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Presentation on theme: "Welcome to Layerscape Session A Generating Data in WWT, creating a Tour (story), and publishing at"— Presentation transcript:

1 Welcome to Layerscape Session A Generating Data in WWT, creating a Tour (story), and publishing at

2 Motivation Why should a Researcher be interested? – Let’s assume that you want to do something around data visualization that goes beyond cool and arrives at useful Why should an educator be interested? – We want Learners engaged; and Layerscape is about interactive exploration How hard is it? – Requisite skills: Know how to use Excel and PowerPoint. You’re set; just need to fill in a few details.

3 How do we proceed? First you install the requisite software. Next you build a dataset Then you import it into WWT Then you play around with it Then you create a Tour Then you spruce up the Tour Then you save and publish the Tour at Layerscape Then you check your published Tour Onward!

4 Tools and Preparation You will need a PC running Microsoft Windows 7 or later and Microsoft Office. This PC should have reasonable graphics capability. The remaining preparation can be done from – Download and install Worldwide Telescope (orange button) – Download and install the Worldwide Telescope Add In For Excel See this page: – Notice that is where you can publish WWT-related content, much like YouTube for WWT. Spend some time using WWT Explore the Look At Earth mode; pan and zoom Learn the basics of navigation including tilting your view Notice the Layer Manager at the left, which toggles on/off using the Layer Manager toggle button at the lower left. Onward!!

5 Resources If you obtained this PowerPoint presentation from – Notice that there are two additional files associated An Excel spreadsheet showing the data we use here A WWT Tour showing the end result of this Session – You can download these files as well (optional)

6 Setting up your data 1 Open Excel and… In row 1 label columns A through H enter: – index, lat, lon, alt, color, magnitude, startdate, enddate – These will be mapped to some of the available WWT data attributes – A partial list of the available attributes is shown at the right Create indices in column A from row 2 down – Values 0, 1, 2, 3, … to 1000 – Why am I doing this? We’re generating synthetic data from scratch – Why? » Because you’ll have complete understanding of this data! » Which is the Researcher premise

7 Setting up your data 2 That lat column will be latitude, then longitude, altitude, color, magnitude, start date, and end date; each row will be a data point or marker Now the slightly painful bit: First make entries in columns j and k as shown at the right, rows 1 – 10. – (can highlight + copy + paste this table) So far 72.5start lat end lat -70start lon end lon delta lat delta lon 1000max index slope lat slope lon 1/1/2000start date

8 Setting up your data 3 Create this formula in cell B2: =$J$1+A2*$J$8 Create this formula in cell C2: =$J$3+A2&$J$9 Create this formula in cell D2: =($J$7-A2)*100 Cell E2 enter ‘white’ Cell F2 enter this formula: =0.25 Cell G2 enter this formula: =$J$10+A2 Cell H2 enter this formula: =G2+3 For these formulas and any that follow: You may wish to cut the text from this PowerPoint presentation and paste it into the appropriate cell in an Excel spreadsheet. To paste: Right-click the destination cell and select Match Destination Formatting (M).

9 Setting up your data 4 Select cells B2 through H2: Double-click the little box at the lower right of the highlighted cells.

10 Setting up your data 5 This should fill in your data column all the way down to row 1002 (where the index = 1000). Whew! Now you have 1001 data points; time to see what this looks like in WWT. To get it there you will use the Excel Add In for WWT.

11 Setting up your data 6 How the Excel Add In for WWT works, in three steps: First you will tell Excel “this is the data I want to import to WWT” (by selecting it and clicking the Visualize Selection button on the Add In ribbon) Second you make sure that the translation of the data from Excel to WWT is configured properly using the Layer Manager panel which appears automatically. Third you “send” the data over by clicking the View in WWT button at the bottom of the Layer Manager panel. The next slides walk you through this process.

12 Import data into WWT 1 Highlight cells A1 through H1002: – Click cell A1 – Use ctrl+shift+right-arrow to select the row – Use ctrl+shift+down-arrow to select the dataset Select the WWT ribbon Click Visualize Selection

13 Import data into WWT 2 How it looks

14 Import data into WWT 3 The Layer Manager appears on the left side. You can replace the default text in the Layer Name box; or you can leave it as-is. Excel has looked at your Row-1 column labels and tried to guess what they correspond to in WWT terminology. This is shown in the Map Columns tab of the center-left table: There is a correspondence between the two columns Data In The First Row and WWT Label. How did it do? – Your ‘index’ was not successfully mapped; it reads “Select One” with a dropdown menu. That’s ok; we don’t need to map ‘index’ to anything; we just used it to generate some of the other data – Your ‘lat’ was successfully mapped to Latitude; and so forth all the way down through startdate and enddate, which mapped to Start Date and End Date – We call this the Label Mapping Phase; and it is complete without you having to fix anything. Onward!

15 Import data into WWT 4 In addition to the Map Columns tab in the Layer Manager there are two more tabs in that central table: Layer and Marker. We will use these later. For now they are fine. Start WWT if it is not already running. Back in Excel, in the Layer Manager panel on the bottom left there is a button that reads View in WWT. Click it.

16 Import data into WWT 5 If all is well you should see the new layer in the WWT Layer Manager. In fact your perspective should have moved to the first data point in the list, somewhere west of Greenland. – Your data should appear as a sequence of white dots – You can zoom in with the mouse scroll wheel until you see the data points – You can select any row in your data table in Excel and click “Go To Viewpoint From Data” to fly to that data point in WWT Henceforth we must maintain “dual thinking”: There is the data in Excel and there is the same data in WWT; a separate copy. The nice thing about Excel is that when your data changes, it reloads WWT automatically so the WWT copy stays current. The Layerscape data model states that your WWT session is about visualizing the data and telling stories around it; and your Excel session is about manipulating and analyzing your data. – In fact Excel is acting as a Data Application or Data App. – It is where you apply your expertise to your data. – We encourage this connection/distinction between WWT and Data App because trying to make WWT both a visualizer and an analytical engine is overwhelmingly difficult, not to mention it re-invents the analytics wheel.

17 Import data into WWT 6 You may need to manipulate the perspective to see your data (a sequence of white dots). Excel tries to take you to the first data point, which is west of Greenland. Notice that in the Layer Manager in WWT this new data is given the name Sheet1_1. That name is a default provided by Excel which you can change to better describe the data. Moderate zoom Zoomed out

18 Data exploration 1 We’ll do three things with the data visualization you’ve built thus far: 1.Explore navigation and viewing perspective 2.Explore Time playback 3.Modify your data in your Data App (Excel) and see how this changes what you see in WWT

19 Data exploration 2 Suppose you want to know where a given data marker is in WWT. Excel supports this using Viewpoints. Select row 1002 (the last row of marker data) On the Excel WWT Ribbon click Go To Viewpoint From Data; you should arrive there in WWT at some zoom level. Zoom in as far as possible to see this marker up close in relation to the background imagery – Image detail varies across the earth – Images shown in WWT are provided by bing maps.

20 Data exploration 3 Ok let’s pause to see the bigger picture for a moment. Session A is about mechanics; so granted the dataset is not too exciting. Once through this, however, session B will be about exploring multiple datasets in relation to one another in what we hope is an interesting way. This will require getting data from a variety of data providers on the web, then using our Excel machinery to bring them all into WWT.

21 Data exploration 4 Fly around your data to get a sense of the transit and gradual change in elevation. Very important: Hold down the center mouse button and drag the mouse around to become familiar with perspective tilting (bottom left figure). Hold down the ctrl+shift keys and hold down the center mouse button, then drag the mouse to bring your perspective below the horizon. You are inside the earth looking up. The surface of the earth will disappear but your data will still be visible. You can experiment with navigation in this mode. For example you can release the ctrl+shift keys and still navigate. Zooming out will cause you to “back out” of the earth on the far side (bottom right figure). You can also move using the left mouse button plus mouse drag, or with the arrow keys. However notice that if (while looking ‘up’) you tilt your perspective in the usual way using center-mouse plus drag (no ctrl+shift), your perspective will pop back out to above the earth.

22 Data exploration 5 If it is not open, open the Layer Manager in WWT (not Excel!) using this control at lower left: Click on earth if necessary to expand it’s layer list You should see an entry corresponding to your data, for example called Sheet1_1 Click this layer; it should now be highlighted Highlighting a layer is an important action; it means that this layer has the current “master influence” over how WWT is manipulating time. While our layer has time data in it, this is currently not activated so all of our data appears ON in WWT. That is, it is all visible. WWT maintains an internal clock, set by default to the current time, which is the WWT “now”. You can manipulate now by setting or causing it to play forwards or backwards at different rates. Controlling time is therefore an important WWT skill. We will continue by doing some simple time manipulations to get a feeling for this feature.

23 Data exploration 6 With your data layer highlighted (see previous slide) check both boxes at the bottom of the WWT Layer Manager: Time Series and Auto Loop – Time Series tells WWT to “pay attention” to time data built into this layer – Auto Loop says “when you reach the end of this layer’s time range, reset to the beginning of its time range” – Notice that our data begins on January and ends on September This is now reflected in the start and end dates above the slider bar in the Time Scrubber Drag the Time slider back and forth – You should see only some of your data visible at any given moment, and the data should give the appearance of moving along from the starting point near Greenland to somewhere down South at the end point on the east coast of the US Oblique view of data implying motion from north to south

24 Data exploration 7 Now we will cause the data to play back on its own, and we will move around as it does so Click on the View control at the top. Notice this is a “split” button; click on the upper part where the View text is. Note the Observing Time window which appears at the right side of the View ribbon Click on the Fast Forward button six times until the text above the playback control reads “x ”. Time is now playing at one million times normal rate. If you have Sheet1_1 highlighted and both Time Series and Auto Loop boxes checked then the playback should loop infinitely, and you can observe the progress of your marker sequence by navigating your perspective along the flight track. You can increase the playback by another factor of ten, causing your marker playback motion to look more meteoric. You can manually override the time by grabbing the time marker (in the time slider) and dragging it to a different location in the timeline You can also play time backwards using the fast-backwards button. – When backwards-play reaches the beginning of the active time range it will hold there. To get it to repeat you must manually drag the time slider to the end of the time range to reset the backwards-time playback. With the playback looping, practice following your marker through space by manipulating your perspective. This eventually gets tiresome but we’ll address that when we build a Tour. 6 clicks

25 Data exploration 8 The last part of data exploration will be modifying the dataset inside Excel and seeing these changes reflected in the WWT visualization. Change cell E2 to the following formula, an “if statement” construction in Excel that chooses a color based on the altitude of the marker Once the formula is entered the cell should read “white”. Double-click the lower right corner of the cell to get it to propagate down the entire column. The change should be reflected in the marker color in WWT. As the marker flies south its altitude drops and it changes color.

26 Data exploration 9 Make the marker easier to see by typing in a larger magnitude. Use the same procedure as on the previous slide: Make all the magnitudes equal to 2 by typing ‘=2’ in cell F2. Then replicate that down the entire F column. Optionally you can do further modifications to you data. For example you could make the trajectory a bit wiggly and a bit random by substituting the formula below in column C (the example is for cell C2). =$J$3+A2*$J$9+0.5*SIN(A2/10)+RAND()/2-0.25

27 Data exploration 10 Again note that as you make changes the data is updated automatically because the Excel Add In considers itself to be linked to WWT. One note of caution: If you decide to make multiple layers in WWT out of a single block of data in Excel you can run into problems. – It is best for now to avoid this practice; for example you can create multiple copies of your source data by pasting the contents of one sheet into successive additional sheets. – The sheets are seen as tabs at the bottom of the Excel spreadsheet. – You can right-click on these sheet tabs and rename your sheets to indicate what each one is for.

28 Creating a Tour 1 Now we’ll make a narrative Tour that tells a story around your data. Start in WWT with your data already loaded as a Layer. From the Explore menu select New + Slide- Based Tour. This brings up a Tour Properties form with lots of possible details to fill in. Give your Tour a descriptive title but for now do not enter any other data in the Tour Properties form. Click Ok. The slide sorter bar appears at the top of your screen. Click Add New Slide. A new slide appears with a thumbnail taken from your current perspective.

29 Creating a Tour 2 Slide thumbnails carry a lot of detail. The number at the bottom shows how long the slide takes to run, in seconds. Click on this and use the down arrow to reduce the slide duration from 10 seconds to four seconds. You can also click on the number itself and type in a new slide duration in minutes, seconds, and tenths using the keyboard. The black bar below the thumbnail can have text. This is useful for longer Tours to keep track of where you are, particularly if the thumbnail doesn’t give that away. Click in the text area and type in some text. The two triangles at left and right above the slide thumbnail are flags to indicate whether you are at the beginning or the end of the slide. In this example the left triangle is illuminated so you are at the beginning of the slide. Click on the right triangle to illuminate it (the left triangle is then dark). The three changes described above are shown in the lower figure at the right. These are the first basic manipulations to a Tour slide. We will continue with a couple more which are accessed using the right mouse button, which brings up a menu of slide editing controls and actions.

30 Creating a Tour 3 Your first Tour slide will play back from your starting perspective. We have modified it to run for four seconds, and technically your Tour is done. But before we save it let’s add one more thing. Navigate to a slightly different perspective in WWT. Right-click on your first slide and select Set End Camera Position. You do not have to have the right triangle selected (yellow) to do this. You can use this same right-click menu to see where your slide starts (Show Start Camera Position) and where it ends (Show End Camera Position). Click the play button to the left of your Tour slide to verify that your Tour runs properly. Click the Save button at the upper right and save your Tour to your computer’s file system. You can give it an appropriate name. We have named and saved this Tour at the Layerscape website under the name Transit Tour from Workshop A

31 Creating a Tour 4 Building Tours is now a matter of appending additional slides. If the next slide begins at a completely new location then WWT will transit between the end perspective of the current slide to the start perspective of the new slide automatically. This can take a few seconds. Alternatively you can make the next slide start where the current slide leaves off. The simplest way to do this is to go to the current slide’s end position and click Add New Slide. – You can also use the rt-click menu and select Duplicate Slide at End Position. This alternative has some additional advantages but can be a little tricky to master; so for now we use the Add New Slide method exclusively. We are assuming your data is currently not activated as a Time Series; that is, the Time Series box is not checked. This means that the entire transit from Greenland to the US is visible. Add a New Slide that moves from your perspective at the end of slide 1 to a vantage point looking down on your data. (Again use Set End Camera Position to accomplish this.) Make the slide duration six seconds and add the slide caption Go To Data. Save!

32 Creating a Tour 5 At the end of your Tour add a third and final slide. Make the Start and End Camera Positions the same (simply do not add a new End Camera Position) and make the duration five seconds. – This adds a “hold” on the end of your Tour so that it does not end abruptly. Add the slide caption ‘End Slide’ and Save the Tour. We’ll consider this a Tour well done and move on to the next stage of Tour building, which will include making your Tour track the playback of your data with time.

33 Making your Tour better 1 Before jumping in to more How To consider the task at hand as a challenge: How might you make a Tour slide that follows your data as it plays out in time as a flight path or trajectory? The key idea is that slide Start Camera Positions and End Camera Positions encode WWT time values as well as spatial perspective.

34 Making your Tour better 2 In Tour playback: A particular data Layer can either be Time Series active or not. Our flight-track data is not Time Active; but we want to keep it that way and also look at it in active mode. Therefore we will create a second copy of our Layer data which is Time Series active. To do this: Right click on the Layer in the Layer Manager, select Copy, then right-click on the earth and select Paste. This will bring up a Data Visualization Layer wizard. We can re-name this copy layer on the Welcome panel and then click Next.

35 Making your Tour better 3 Click Next in the Wizard three times to arrive at the Markers panel. Check the box that says “Show Far Side Markers”. This makes markers visible from an upwards-looking viewing perspective which will be important shortly.

36 Making your Tour better 4 Click Next in the Wizard two more times to arrive at the Date Time panel. Notice that there is a Time Decay slider which you can set as you like. When a given data point (marker) reaches its own End Date it will gradually fade out over days. – If you set this to the minimum value of.0002 the marker will vanish instantly. – If you set it to a large value like 64 the marker will take quite some time to fade out Notice that the Begin Date Range and End Date Range are correctly calculated based on the earliest and latest times present in your Layer data. – You need not have these data points sorted in chronological order for this Begin / End calculation to work correctly.

37 Making your Tour better 5 Click Finish in the Wizard and note that your new layer now appears next to your original in the Layer Manager – You can re-open the Wizard and modify your Layer’s configuration at any time: Right-click on the Layer in the Layer Manager and select Properties, then select the tab you need. – Use this method now to set your Decay Time for the new layer to 32 days Highlight the new layer by clicking on it and check the Time Series checkbox at the bottom of the Layer Manager You now have a Time Series active version of your flight track data. Un-check the box in the Layer Manager next to your original data. That data should no longer be visible.

38 Making your Tour better 6 Add a new slide to your Tour and position it as third- in-line from the start. – Click on Add New Slide – Label it Time Slide – Set its Duration to 21 seconds – Simply drag the new slide to where you want it to be Ensure that your original Layer is de-selected, that the new Layer is selected and that it has Time Series checked. – The Time Slider should have start and end dates as shown at right Drag the Time Slider back and forth to see your data moving along its flight path. Locate the beginning of the flight path and move your viewing perspective to see this starting point obliquely, for example as shown here.

39 Making your Tour better 7 Now the nifty part: Right-click on your Time Slide and select Set Start Camera Position. Use the time slider to set the WWT to the end of your Layer’s time range Maneuver your perspective so that you are now looking at that data at the end of the Time Range Right-click on your Time Slide and select Set End Camera Position Save your Tour Play the Tour to see two things: – How did WWT manage the transition from the end of slide 2 to the start of the Time Slide – How does the Time Slide playback look? Does it track the data well or does it lose track of the data at some point? – If the Time Slide does lose track of your data (perhaps only to regain sight at the very end of the slide) you can re-do the setting of the start and end camera positions. You may need to pull back your perspective It may also help to try and look in the direction of the flight track When I tried this I noticed that the start of my End of Tour slide was disconnected from the end of my Time Series slide; there was another transition that I did not want. Next we will remedy this.

40 Making your Tour better 8 Click on the Time Slide and click on the upper-right triangle. This takes you to the end-position of this slide. Right-click on the End of Tour slide that follows and choose Set Start Camera Position. You have now adjusted your End of Tour slide to the same perspective as the end of your Time Series slide. Save the Tour and play it again to make sure you are satisfied with everything.

41 Making your Tour better 9 The last step is to add a text box that includes a time indicator. Start by selecting the Time Slide and the start camera position (upper left triangle on the slide) Click on the Text icon at the upper right to bring up a Text Editor Type in some text but do not hit Save just yet. At the upper right of the Text Editor is a Special Items icon with a drop-down menu. – Select Date – Select Latitude – Select Longitude – Space these out in the text box using spaces or carriage returns – My end result is shown at the right – Now click Save at the upper left of the Text Editor Position your text – You can drag and resize it as in Power Point

42 Making your Tour better 10 Save and Play your Tour You should now see your Time Series data play back with a dynamic display of date, latitude and longitude Congrats! You have learned the fundamentals of Tour authoring in WWT – There are many advanced features which we leave for another session – Now let’s publish your Tour at Layerscape

43 Publishing your Tour 1 This needs expansion Gotta have a Windows Live ID Gotta go to and Agree to the TOU Click Publish, choose General Interest Go through the metadata: What it means Done? Great; but let’s verify: – Search for and find your Tour – Run it from LS to make sure it is there safe and sound – us the link!!! We’ll send you an XBOX, we promise!!! – Actually we’ll send you either an Xbox or an epiphyte, our choice

44 Where to from here? Session A was a lot of stuff; so again congratulations on getting through it all! In Session B we will explore the visualization potential of Layerscape in an Education setting. We will download a Tour and practice disassembling the data, then reassembling a new Tour from that. In Session C we will explore Reference Frames. Earth is a reference frame; but you can create a new reference frame in relation to earth. Send feedback or questions to we would be delighted to hear from you! You can also take our online survey

45 Welcome to Layerscape Session B Retrieving data from Tours, GEOMETRY, and more on Tour editing

46 Session B Welcome to Session B. Here we will work more with Tours and Tour content, i.e. Getting data into WWT for visualization. We first remind you that the WWT top bar buttons are actually dual buttons: The big button centered on the text (Examples: “Explore”, “Guided Tours”) is a button that gives you a custom control panel just below the menu bar. Put your cursor over Explore and you will see a second small thin button below the text that gives you a dropdown menu: Here the big button is referenced using text: “Explore” means the big button. The small button is indicated here by appending a small v subscript: “Explore v ”. Please begin by downloading a Tour from Layerscape (Save it as a file on your computer): Open WWT and Explore v > Open > Tour… to load the above Tour in Edit Tour mode. To ensure you are Editing and not Viewing the Tour: Click on Guided Tours v. If the text “Edit Tour” is visible in the drop down list: Click it. You can still watch Tours play back in Edit mode; but you can also Edit the Tour, which is what we want. This is an important detail to remember if you find yourself unable to edit a Tour! Big button Small button

47 Reminders on Basics Tours can be viewed in WWT in two modes: Edit and Play. Double-clicking a Tour file to start WWT will bring it up in Play mode. Opening a Tour from the WWT Explore v dropdown menu opens it in Edit mode. When you are in Play mode the Guided Tours v menu lets you switch to Edit mode. In Play mode the space bar acts as a pause button. During Tour playback WWT will go into full screen mode if the cursor is in the center of the screen. To enter full screen mode when the Tour is not playing press F11. To return to normal mode press ESC.

48 Extracting GEOMETRY Ensure the Layer Manager is open: View v > Show Layer Manager. In the Layer Manager click the + sign to the left of Earth to expand the layers attached to the Earth. Right click on the Layer called “Vector Field 7/12/2013 8:28:56 PM” and select Copy. Open Excel, create a new spreadsheet, right-click on Cell A1 and select Paste. This should create entries in cells A1 through Each row is one of the vectors you see at the beginning of this Tour.

49 GEOMETRY continued 2 Notice that you can now save this Excel spreadsheet as an Excel file. Do so now, then halt Excel and halt Worldwide Telescope. Then re-start Excel, load the spreadsheet you just saved, and re-start WWT (without loading the Tour). The point here is to simulate “starting from scratch” after recovering data from a WWT Tour. Now reverse the process: Highlight cells A1 – C12190 in Excel, right-click, and select Copy. In WWT open the Layer Manager, right-click on the Earth, and select Paste. This is the “obvious” part of cutting and pasting from Excel and it was covered in Part A of this Tutorial as well. Notice that your Paste has brought up a Layer Properties Wizard. You may wish to enter a new Layer name such as “Recovered Vector Field”. The click the Next button three times to arrive at the Markers configuration page. Click the “Show Far Side Markers” check box. Then click Finish. The vector field should now appear, as it did before in the Tour, off the southwest coast of Australia. You can go explore this data; but you may find that you can not swing down underneath to view it from below. This capability must be enabled so that your tilt ability does not halt at horizontal. Click View v > Allow Unconstrainted Tilt. Now using (middle mouse click + drag) or if this does not work (Ctrl key + right mouse click + drag) you should be able to change your viewing perspective angle to below the surface of the earth looking up. You should still be able to see your vector field from below because you clicked on the “Show Far Side Markers” checkbox in the previous step.

50 GEOMETRY continued 3 Returning to the Excel spreadsheet: Notice that unlike in Session A there are no latitude or longitude columns. Rather each vector is represented as a row containing an entry like this: That “LINESTRING((109…” entry is a format known as Well Known Text (WKT). For more on this see the Wikipedia article here:

51 GEOMETRY continued 4 Notice also that the column header for the WKT (Excel spreadsheet Column A) reads “geometry”. WWT interprets this to mean “Rather than latitude and longitude columns we will use WKT entries to provide position locations in this column. Our example LINESTRING entries in WKT are triples separated by commas: First longitude, then latitude, then altitude. Notice this is a rather tricky “gotcha” if you happen to be accustomed to writing latitude then longitude.

52 GEOMETRY continued 5 This concludes our introduction to WKT and GEOMETRY. It expands our drawing capabilities in WWT beyond markers to lines; and we will visit a further extension to polygons in a later section of this workshop. Notice that, like Markers, GEOMETRY objects can have color and date attributes (Columns B and C in the spreadsheet). They can also have a magnitude attribute but this has no actual effect on how the WKT objects are rendered.

53 Creating a Collaborative Tour Suppose you have the Vector Field loaded in WWT. You can imagine another WWT session that has a different data layer loaded, and so on; several data explorations. Let us next consider a “team project” where your goal is to build a single Tour from multiple source Tours. The approach here is for you (and possibly your colleagues) to build individual short Tours around specific data layers. These layers might be recovered to individual source data files using the procedure outlined above for pulling the Vector Field from the large Tour. (Recall that was just one Layer of about 40 layers built into this Tour; some of which reside in a reference frame called ‘vk’.) Once you have built several source Tours we will want to assemble a longer concatenated Tour; so this is the procedure we describe next.

54 Collaborative Tours 2 In Session A we describe creating and saving a Tour to your computer. The file extension will be.wtt for “Worldwide Telescope Tour”. Create 3 Tours, each fairly short, around different datasets, starting with a Tour built around the Vector Field we described above in Session B. Let’s call these Tour files T1, T2, and T3. Re-start WWT so there is no Tour loaded, then create a new Tour using Guided Tours v > Create A New Tour. Give the Tour a name and any other information you wish to add, click the Ok button, and click Add new Slide in the slidebar at the top of WWT.

55 Collaborative Tours 3 You should now have Slide 0 in your Slide Bar. Right-click on this slide and click on Master Slide. An M appears in your slide at the upper left. You can make as many Master slides as you like. When the Tour plays it will carry information from a Master slide into subsequent slides until the playback encounters a new Master slide, which will then supersede the prior one.

56 Collaborative Tours 4 With your Master Slide highlighted (yellow border; see image from previous page) click on “Text” at the upper right. This brings up a Text Editor.

57 Collaborative Tours 5 Type in some text, like “Collaboration 101”, and click Save in the text editor. Your text now appears “stuck to the glass of the monitor” in WWT. (It is not “stuck to the earth somewhere”). Drag the text to the lower left corner so it will not occupy the center of the frame. This text will persist throughout the Tour because it has been placed on a Master slide.

58 Collaborative Tours 6 Right click on the Master slide, slide 0, and select Merge Tour after slide… You can now browse to and select one of your tours, T1.wtt. Do the same for T2 and T3, merging after the last slide of the Tour. You should now have concatenated your three Tours into one. You can experiment with transitional frames between Tours, with adding explanatory text, adding shapes and illustrative pictures (again see the menu items at the upper right); and you can even add audio narrative and a background music file. The background music must be attached to a Master file so that it continues to play after the Master slide is done and the Tour continues to the subsequent slide.

59 Session B Conclusion This concludes Session B where we have covered A new drawing tool for lines: The GEOMETRY column header and LINESTRING format from within the Well Known Text paradigm. Assembling a single Tour from multiple Tours, also using the Master Slide. In Session C we will explore Reference Frames and explore a little of what is available in the Solar System mode of WWT.

60 Welcome to Layerscape Session C Reference Frames and Planetary Science using WWT Solar System mode

61 Session C We will begin by creating a static Reference Frame on the earth and populating that with data. We will create a Reference Frame that orbits the earth; and another that orbits the sun.

62 Creating a Fixed Reference Frame Start WWT and select Look At: Earth. Navigate to a local topographic high point (optional). I went to the top of Mount Rainier. Open the Layer Manager and right click on Earth, select New Reference Frame. You now go through a three-panel wizard to complete this process.

63 New Reference Frame 2 Here are the three panels in the New Reference Frame wizard. In the first panel just provide a name and keep the default FixedSpherical. The second panel describes the Reference Frame and its geometric relationship to a parent Reference Frame. The default values are fine here; click Next. The third panel places your Reference Frame at some location within the parent Reference Frame. I used the “Get from View” button to get the latitude, longitude and altitude of my cursor (Surface Reference Point or SRP). I can now click Finish.

64 What do I do with my new RF? Let’s abbreviate Reference Frame as ‘RF’. You should see your RF in the Layer Manager under Earth. This RF is fixed or “bolted” to the earth. At lower left select Look At: Solar System Only in this mode: Right click on your RF in the Layer Manager and notice the option “Track this frame” is available. Select it. Your perspective is now attached to this RF (whereas a moment ago it was attached to the earth). You can rotate around this RF and you can zoom in and out. But you can no longer pan across a spherical surface as you do when your focus is the earth. The RF you have created uses 3D coordinates, by default our stand-by latitude/longitude/altitude which is a version of spherical coordinates. However you can also work with this RF using rectangular or Cartesian X Y Z coordinates. This is more natural if your RF is intended as a “base of operations” for local data representation. Notice that your RF spherical coordinates include an altitude… and this begs the question “altitude above what? There’s nothing here!” Well by default the altitude is relative to a sphere, and the radius of that sphere is one of the parameters in the second RF Wizard panel. You can open this up and edit it by right-clicking on the RF and selecting Properties. Our next job will be to place markers in our new RF to see what the orientation of this RF is in relation to its parent, the earth. One last comment: If you placed your RF on top of a hill you may find that the center of focus is now located up above the surface of the earth. This is because topography is disabled in the solar system view of the earth.

65 What Do I Do With My RF 2 There is a lot of information about your static bolted- to-the-earth RF in the previous slide. We recommend (if you skimmed over it) going back and giving all that text another casual glance. The RF is a pretty powerful construction in WWT but with great power comes some complexity. If you’d like to create a real reference frame: You can purchase three pieces of wood trim fairly cheap and mark them off with a meter stick, then prop them up say in a classroom and label them X, Y and Z. Or you could use an open cardboard box. In both cases you can physically translate your RF around.

66 What Do I Do With My RF 3 Open Excel and create a little table of data: four column headings { X, Y, Z, color } and five rows of data below them, as follows: Notice that these are colored dots that will mark off coordinate axis directions in an RF. We use 1000 rather than 1 because we are working in meters in a fairly large playing field. Copy this table and paste it into your RF. On the first page of the data paste wizard: Be sure to select Rectangular in the drop-down menu for Coordinate Types. (See Session B for more on copying and pasting into / out of WWT.) xyzcolor 000white red green blue 1000 orange

67 What Do I Do With My RF 4 Your data should go in with no further “tricks” in the Data Paste wizard. If you are still in Solar System mode you can zoom as necessary to see your data. Remember it should occupy a cube about 1 km across. Return to Look At: Earth and find your data. You are no longer in “Follow RF” mode so you can scroll about the earth normally. Your new data should be perched atop the hill you selected when you created the RF; and your origin point (white) will be at the origin of your RF. Here are my data points, atop Mount Rainier. They are a bit too bright so I will use the layer Properties to fade them down. The orange dot at (1000, 1000, 1000) serves to show the positive direction from the origin; and the red, green and blue dots show the X, Y and Z axes respectively.

68 What Do I Do With My RF 5 I notice that my positive x-axis is aligned north-to-south and my positive y-axis is aligned west-to-east. I would prefer the more traditional alignment of: X = increasing west to east, Y = increasing north to south. This is easily accomplished using the Properties wizard for the reference frame: Right click on the RF and select Properties. There are now two tabs here: General Options and Position. On the first of these, the General Options tab, enter the value -90 for Heading. This means that your entire RF has been rotated by -90 degrees in the left-handed sense about its own Z axis, relative to the parent RF, the earth. You should now see your axis dots aligned in the manner given above where increasing X coordinates will go from west to east from the origin. A very important point to notice here is that a static RF is created at some location (remember we populated the locations fields using the Get From View button in the wizard) such that the xy plane is locally tangent to the surface of the earth. This is very convenient for doing localized data representation where xy coordinates are “flat on the ground” and z is altitude. If you need some other orientation of axes you can experiment with the RF properties Heading, Pitch and Roll. What if you relocated your RF? In WWT: Go to a mountain top somewhere far away. Right click on your RF and select Properties. Go to the second tab, Position, and again click on Get From View, and click Done. Your data should now appear as your RF is relocated to where you are looking; and it should still have the orientation described above: xy plane is flat, x points east, y points north, z points up. The RF is translated around the earth according to this convention.

69 What Do I Do With My RF 6 Here are some concluding remarks on RF use after this initial introduction: RFs are good for local Cartesian representation of data When an RF is relocated or nudged around or rescaled: All the data in the RF comes along for the ride. Data in a RF is subject to the same rules about time as other data in WWT. Markers will blink in and out of view based on an optional date column: provided Time Series is enabled for that layer. While Cartesian support (X Y Z coordinates) is in place for data markers as we have seen here, as of today (August ) there is no support in WWT for Cartesian coordinates for WKT GEOMETRY, specifically LINESTRING or MULTILINESTRING construction. There is more to this subject, however, provided in the Appendix to this section C of the tutorial. Other RF types can be made to move – for example orbit the earth or the sun – so we’ll move on to that next.

70 Creating an orbiting RF Go to a web browser and search on “Two Line Element”. Your search results will include a website with the term ‘Celestrak’ in it. For example: A Two Line Element (TLE) is a shorthand way of describing an orbit in terms of a set of numbers. For this Tutorial we will consider a TLE to be a short block of text that we copy from a website like Celestrak and paste into the WWT New Reference Frame wizard to create an orbiting RF. At Celestrack or in Wikipedia or wherever you find a TLE: Highlight and copy the TLE text. Here is an example: Notice I do not highlight the “ORBVIEW 2 (SEASTAR) text; just the two lines of numbers that comprise the TLE.

71 Creating an orbiting RF 2 Assuming you have copied a TLE into your text buffer… In WWT in the Layer Manager right click on earth and select New Reference Frame. In the wizard provide a name for your RF and select Orbital for the Offset Type. Do nothing under the second panel (General Options) except click Next. In the third panel click Paste TLE. This will populate the fields and you can click Finish. A RF should appear underneath the earth. Go to Look At: Solar System and right click the RF. Select ‘track this frame’ Click on View at top center (the text, not the down caret) and note the state of your Observing Time clock. This clock by default will say “Real Time” and time may or may not be elapsing. If time does not appear to be elapsing: Click the play button. Look at the earth. If everything has gone well it will be slowly turning under you. It should take about 100 minutes for one orbit. You can use the Fast Forward button on the Observing Time control to speed up time by a factor of 10, 100, etcetera. Pressing the play button will slow time down by a factor of 10. Before going on to the next step, a warning: If you paste data from a table into a WWT RF and your zoom level is set very low (your observing location is close to the origin): You will be very close to your data and it might be overly bright. If you have a lot of bright data your display driver might be overwhelmed and it might crash. Take care in the wizard to set a global marker scale value that is small to try and avoid this unfortunate series of events is pretty safe; and zoom out some. Then after you paste your data you can make it brighter as needed by Right-click Properties in the Layer Manager. Paste your table of fiducial points from the prior exercise into this new RF. You should be able to see the orientation of the x y z coordinate axes in your RF with the proper zoom level.

72 Creating an orbiting RF 3 Here is a screen capture of the reference points in orbit about the earth. The earth background is Blue Marble; so it is unfortunately lower resolution than the bing maps overlay available in Look At: Earth mode.

73 Tutorial C: Appendix 1 Placeholder Cartesian GEOMETRY WWT (circa 2014) has two forms of coordinate support for markers (point-like data). The first is earth-centric: Latitude, longitude, altitude. The second is built into a Reference Frame as Cartesian coordinates: x y z. The same can not be said for GEOMETRY data in WWT. As noted, GEOMETRY conforms to one of two specific formats within the category of Well Known Text (WKT). These are LINESTRING and POLYGON constructions. Note: MULTILINESTRING is also supported; and MULTIPOLYGON may be as well; this open question is left as an exercise. Because lines are very useful in visualization it can be seen as a limitation that there is no Cartesian coordinate support for LINESTRING in WWT. This appendix is a placeholder for an extended description of how to do necessary transformations to data to attain this capability.

74 Tutorial D This tutorial will describe: The use of polygons in WWT Polygons are n-gons that are shaded on top and on the sides. Polygons share attributes with Lines (Appendix C) and Markers (Appendix A). They can be assigned a color and an opacity. They can have an altitude that is commonly scaled to some geospatial data value such as water storage. And polygons can have no associated time; or a start time; or both a start and an end time. Hence they are applicable to static display of information and to time series display.

75 From Excel We create a data table that we will cut and paste into WWT as shown in previous tutorials. Column A = GEOMETRY Cell A2 = POLYGON((0 0,0 1,1 1,1 0,0 0)) Column B = date Cell B2 = 1(i.e. Day 1; actually date not important) Column C = altitude Cell C2 = 5000 Column D = color Cell D2 = the following text block: =IF(C2<6000,"red",IF(C2<7000,"yellow",IF(C2<8000,"green",IF(C2<9000,"cyan",IF(C2<10000,"blue","white"))))) To propagate things properly: -Copy cell A2 to A3, Copy D2 to D3, and set B3 = B2 + 1 and C3 = C Highlight cells A3 to D2 and drag the small square at the lower right corner of cell D3 downward to row 80

76 Transfer to WWT Copy the entire cell block from A1 to D80 and paste into the Earth layer of WWT. In the Paste Layer wizard you may wish to set the Decay time to 1.0 or 2.0 (days). You should now see a 1-degree square polygon, white, at Zero Lat Zero Lon on Earth. Right-click the Layer in the Layer Manager and set the opacity to about 20%. Highlight the new Layer in the Layer Manager and click the Time Series box. The square now disappears as you are “just prior” to the start of the POLYGON time series. Move your viewing perspective to an oblique vantage point and drag the time slider. The polygon should cycle through colors and should increase in height over time.

77 Notes on POLYGONs Notice that the POLYGON coordinates give longitude first, then latitude; and that the altitude is given as a separate column. It is also possible to give the altitude as a third coordinate inside the POLYGON definition string in lieu of the altitude column. Notice that the POLYGON vertices make a closed circuit: The last vertex is the same as the first. The last (closure) edge is not automatically filled in, and each edge produces the skirt that goes from the edge to the surface of the earth. Hence it is standard practice to be sure to close the POLYGON. Follow the polygon vertices: They are presented in a clockwise order. If they are presented in reverse order then the visibility of the polygon becomes “from within” rather than external. As shown with only a “date” column each POLYGON is rendered and then gradually fades out over its Decay time (see the Properties wizard). To change this to a sequence with no fading include an additional column called “end date”, set these values = date + 1.0, and set the Decay time to Zero. Notice that the edges of the polygon are straight lines; they do not conform to the earth’s surface. If you draw a very large polygon its center will disappear below the curvature of the earth; there are no “tent poles” holding it up.

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