Friday, March 28, 2008

Labels via Overlays

Stefan's post about the Wilkins Ice Shelf breakup has brought several thoughts together that I will post about shortly. Today I'll discuss labels which develops ideas I have posted about before:

In his post Stefan links to a Google Earth file where he has just put two images together as overlays on the ice shelf (no criticism of Stefan is meant by this disucssion, he has just reacted to events with a quick kmz which was worth doing), you'll notice that the labels are incorporated into the images which means you can't turn them off as a separate layer. Being able to toggle labels on or off is useful as it enables you to unclutter the screen. To add a label as a separate layer you could add a path (the line) with a placemark with no icon (the label) but the problem with this is that the text will rotate around and keep its size as you zoom around. Another approach is to add the label as an overlay, I've done both in an example below:

Screen shot showing two types of way to add labels in Google Earth

example kmz file

Backstory: In the area shown the Brahmaputra is eroding paddy fields, you can see the evidence of this by roads no longer leading anywhere. I'm working on this as a lesson plan for schools.

If you zoom in and out and rotate in GE you can see the different behaviors. The placemark/path is easier to do but if you have several of them in a view the way the text keeps its size clutters the view so I think the overlay works better. Notice I also chose white as the colour for the labels as the background is dark, if your label is sitting over a mixed background of light and dark you may want to put some sort of semi transparent background beneath the label to make it stand out more.

HowTo: To produce the overlay you want to use your favourite image package (I use Fireworks) to produce text and a line as a transparent .gif file using index transparency. Valery has produced a web app that does this for you, I haven't tested it as I'm happy with my fireworks to .gif workflow but it's worth a play.

HowTo make a semi transparent background: To produce a semi transparent background I would produce a white, opaque square as a .gif and load it into Google Earth so it is below the label. You can alter its transparency in properties and make it plot underneath your label by using draw order: properties > location tab > draw order.

Wednesday, March 19, 2008

Talk in Google Earth: HowTo

Yesterday I was one of 4 speakers at an outreach event run by Southampton University on the topic of 'Use and Misuse of the Oceans' for Year 10 students. The keynote speaker was Chris Packham who was mobbed for his signature all day. He was kind enough to compliment me on my talk which I'd done completely in Google Earth.

Screen shot from the talk showing the rough location of Lake Aggassiz, the Laurentian ice sheet and outflow routes during the last ice. This lake sometimes breached its banks catastrophically and the rush of fresh water to the NE Atlantic may have interrupted the North Atlantic drift.

The key reason for doing this was that my talk discussed geographical/oceanographic features that varied from thousands of km down to a few m in size and also that the spatial relationship of the features to each other was important. However, there were a few difficulties with giving the talk totally in GE:
  1. GE is prone to crash with the amount of data I had produced for the talk
  2. Motion in GE on a laptop is liable to be 'choppy' because of the lack of a powerful graphics card
  3. There was no wireless in the venue

My solution was to record the talk using GE and Fraps as little movie clips then to combine them together as one movie clip. It sort of worked. The problem is that whilst Fraps records the Google Earth background very well it fails to capture images and movie clips embedded in pop up bubbles so these have to be linked separately. Also, working video controls in the actual talk (play and pause) proved tricky, a slideware navigation system (next, back) is much easier. Another feature of this approach was that navigating the movie clip introduced little gaps in the movies as I struggled to synchronize what I was saying with the events on screen, Chris said he thought it actually helped as it allowed the school kids to process what was happening but I would like to be more in control of the action.

A solution to this is:
1] Produce talk in Google Earth
2] Record GE transitions (i.e. flying from space to Plockton on the West Coast of Scotland) using Fraps as .avi movie files.
3] Import .avi files into separate slides in powerpoint.
4] Find youtube videos and convert and download to .avi files using Vixy
(note I haven't used it but it looks better than the process I used)
5] Embed those .avi files as separate slides

I'll be releasing the KMZ file of the talk at a later date, I want to polish it a little more.

Monday, March 10, 2008

New Video Tutorials

Aug 2010: Now Updated

Screen shot (partly doctored) of part of the tutorial

Summary: Want to learn the basics of Google Earth? I've created a two part set of video tutorials, part 1 teaches you how to navigate in Google Earth and part 2 teaches you the basic tools for creating and saving an interactive map.


Rational: The videos are embedded within Google Earth itself, there is an overlay image with instructions and videos are within placemarks on top. I hope this set up encourages users to practise creating content in GE. This hasn't been done before with videos (to my knowledge) but is similar to how the basic tutorials in sketchup work. There are multiple sources of teaching material about Google Earth; Google's own text and video tutorials, my own v3 video tutorials out there and even a manual for how to use Google Earth. Given I am always pointing out 'just because you can does not mean you should', why am I publishing yet another set of tutorial materials?
  1. By putting tutorials within GE itself I think there is more chance that users will practise using the tools rather than just reading/watching and to learn, 'doing' is much more effective than 'reading'.
  2. The Google documentation is thorough but for a beginner I think it goes into too much detail, there is value in a newbie completing a well bounded task. In the tutorials users use the basic tools to create and save a map for new students coming to Southampton University - a complete task. The 'more' placemarks link to other web resources if they want to research beyond the core materials of the tutorials.
  3. I am always on about good design and I mix some basic design good practicises into the tutorials - not just HowTos but also BestTos. My experience of teaching is that it's better to mix design skills in with technical skills rather than approach them separately.
However, the result is not perfect. GE wasn't designed with this use in mind so it took a lot of fiddling to get it to work properly. There are still some rough edges left; not being able to control exactly how much of the screen the main overlay takes up (so I have to instruct users to move the screen around) is an example problem. And it won't work in mac GE because the movies are flash based.

Having said that, I think it was still worth doing because of reason (1) above. I'll be interested to see just how sucessful it is at leading people to practise creating Google Earth maps.

If you wish to re-use it for training users/students yourself, it's published under a creative commons license;
Creative Commons License
part of the justification for doing this was the outreach potential for the school of Geography so attribution is important.

Friday, March 7, 2008

Digital Watches are Cool

Since my post on the parallels between traditional crafts such as pottery and building Google Earth projects I've been musing on the 'we are infatuated with the tool' idea as applied to Google Earth. The basic idea of this is that upon introduction of a new tool there is usually a period when experts apply the new technology uncritically in applications where it shouldn't be used. I've come up with a couple of analogies:

The Atomic bomb: Following its infamous use in the 2nd World War 1950's engineers came up with a bizarre set of uses including setting off a series of bombs to build giant canals (from Bill Bryson's wonderful autobiography) and even a plan to use atomic explosions as rocket fuel.

Following this period of mad ideas we now have a well developed sense of the limitations of nuclear fision.

The second example is illustrated by a quote from Douglas Adams:

"[of humans] ...a race so backward they still thought digital watches were cool"

My dad used to have an analogue watch which I was allowed to wind up every evening. My interest didn't last, I clearly remember hounding the first kid at school who got a digital watch, I wanted to keep pressing the buttons to see those magic red figures light up. Unsurprisingly he wanted me to buzz off and stop wasting his watch battery. The infatuation with digital watches we all had didn't last of course, if you're wearing a watch as you read this its probably an analogue watch run by a quartz battery watch. Again, following a fascination with one technology (quartz digital watches) we quietly learned how to use the technology properly - the hype didn't last.

Neither of these examples are perfect, you could argue that the public have an overly developed fear of nuclear radiation which affects our present use of nuclear technologies. You could also argue that the popularity of analogue watches is linked to aesthetics as much as practicality. However, the analogies are there to illustrate the idea rather than be completely water tight and I think they work rather well.

So are we in the 'cool digital watches' period with the virtual globe technology? I would say we are, you don't have to look far to find Google Earth projects with badly thought out icons, overly bright lines and a bafflingly complex structure in the places column. The faster we get over our infatuation the better.

Which isn't to say Google Earth isn't a great tool, I wouldn't be blogging about it if I thought it was rubbishj, it's just we're not using it correctly yet.