Friday, February 13, 2009

Time Tip: Edit in Google Earth 5

Update 16 Feb 09: Cory and Barry point out in the comments that the time dialogue isn't there to change the 'main' time tag, i.e. the one that will control whether an element is visible or not when you use the timeline (the one that's been around in earlier versions of GE) but its to do with the new 'gx' time tags. Read their comments for details but I will say here I think this isn't great for usability, a dialogue labelled 'time/date' is going to cause confusion for people who won't know which time tag they are editing in properties.

I haven't seen this flagged anywhere on the web yet so a quick tip:

Instead of having to edit the KML to add a time tag to your data so it can be viewed with the timeline you can now edit it directly in Google Earth:
- Right click in the places column > Properties > View > Date/Time.

I actually got a friend to build me a little .NET application so I could edit time tags in KML as it was so tedious to do it manually (and I kept on making mistakes). Neat that this has been added in GE5.


Cory said...

One of the reasons for this is to add the timestamp for historical imagery. When you create a placemark with historical imagery active, the date of the imagery you are looking at will be added. Open the placemark, activate historical imagery, it will then jump to the correct date.

You can also add the date to an already existing placemark by switching to the relevant historical imagery and using "snapshot view".

barryhunter said...

Be careful tho. Google Earth 5 (and the gx: namespace) includes two distinct time specifications.

1) the original "feature time" that controls when the feature is visible (particully useful for animations), this is stored directly in the <Placemark> etc. Docs

2) the "view time", which controls where the timeslider jumps to when double clicking or loading the file. Basically is specifies the ideal time period for viewing the feature. This is stored in the <Lookat> or <Camera>. Its actually mainly introduced to facilitate tours, via the gx: extension namespace. Docs

The first is the usable since GE4, but its only the second one that is now editable in Properties using GE5.

So to edit the original (and probably the most useful) time specification you still need an external application.

Rich Treves said...

Ahhhhh! IMHO that's a really odd thing to do. Thanks for pointing it out guys.


JB said...

As Barry points out the addition of "time" to views was basically to facilitate tours in space and time.

For those editing directly in GE, it would be nice to have a "time-tagging" option for the visibility in the GUI, but there isn't!

One important point to note for tours using Historical Imagery; Once a time has been specified, GE will continue in that era until told otherwise. It has no concept of "the present". If you want to return to "now" add a TimeStamp of 2999 (or sometime in the future) to the "view" of the next feature your tour flies to (See Barry's second KML doc reference).