3D viewers as web page plugins are often difficult to use. Many require Flash or Java in the browser, which is problematic in several ways. Some failed to gain traction with the general public due to complex user interfaces or learning curves.
We wanted a simpler solution, a way to rotate and zoom in on sets of earthquakes which would be both easy to use and lack the complexity and security issues of the plugin approach. 3DV uses standard HTML5 techniques to accomplish that goal.
It is normally invoked from the IRIS Earthquake Browser (IEB), on a selected set of earthquakes. 3DV can also be invoked directly by simply bookmarking it.
This project began in 2011 as a copy of the cool, molecule-viewing webapp called CanvasMol, with the gracious permission of the author. Also, Gary Parvis kindly contributed the use of a regional coordinate conversion algorithm and related source code.
Use the mouse wheel or plus/minus buttons to zoom in and out.
Drag with the mouse or finger to rotate.
The View menu lets you do things like:
- hide/show axes, coastline and/or plate boundaries
- reset to a known position, such as "look down" or "look north"
- auto-rotate around one or more of the three axes
- make the spheres smaller or larger, shaded or solid
- take a snapshot of the scene as a PNG image
On mobile devices the performance will be quite a bit slower. Tablets generally work OK, but the smartphones tested were not very satisfying. Fewer earthquakes, under maybe 800, is best for mobile use.
In all cases turn View / Shading off to drastically improve performance.
3DV is best with Chrome, Safari, Firefox, Opera, Edge
Internet Explorer is generally not targeted for support.
Start with smaller numbers of earthquakes, such as 800, and work up. Turn shading off if things are slow.
The number of earthquakes you view is critical to the performance of rotation and zooming. If your browser becomes unresponsive (you might even need to restart it), reduce the number of earthquakes selected in IEB and try again. Older computers and browsers are more prone to this limitation.
If you drag the with mouse and do not see immediate rotation, then release the mouse and wait a bit, then consider dismissing that window and starting again with fewer earthquakes.
Turning shading off in the View menu can help tremendously.
Savvy computer users will notice that a 3DV URL contains parameters (such as lats; lons; ranges of time, depth, magnitude, etc) which can be changed by directly editing them.
Feel free to experiment, but this method of invoking 3DV is not well-tested at this time.
- Although you are able to select very large regions in IEB for viewing in 3DV, it isn't satisfying. The spherical nature of such regions, the distortion of the axes, and the erosion of the concept of "up" and "down" make it interesting, but unrewarding. A rule of thumb would be don't bother with regions that are more than about 1/4 of the world. And more earthquakes, in small-to-medium regions, tends to be more interesting.
Over time we will build a gallery of various movies either made by ourselves or submitted by users. Here are a few starters:
Southern Italy demo (Anim GIF 12 MB)
20,000 quakes in Alaska (large) (Anim GIF 12 MB)
20,000 quakes in Alaska (med) (Anim GIF 2.6 MB)