Easy Lat/Lon Changes in Sky Mode
In addition to the existing azimuth controls, it would be great to be able to easily change lat & lon in sky mode. I see it can be done with shift+LMB in the viewport, but this doesn't let me lock to changing only one or the other or let me land on exact figures. This would be really great for observational astronomy demos (easily changing between local latitude, poles and equator, for example, without returning to orbit/surface mode in the meantime).
Is there also a custom command that can be sent to do this (and fly to sky mode/surface mode locations in general)?
Also, re: precession, am I correct in observing that the pole precesses, but not the equinox? At least, not the ecliptic/equatorial grids. They still intersect in pisces and virgo no matter how far back/forward in time I travel.
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Yes, I reported this to the SCISS people via Sara back in June after they fixed the bug in v 1.6 that prevented me from going to a "BCE" year. It appears that the star catalog is precessed correctly, but the grids are not precessed. For example, when I go to 2800 BCE, the night sky does indeed rotate around Thuban in Draco and not Polaris. However, when I bring up the celestial coordinates grid, the N.C.P. is still marked at Polaris. (So I keep the grids off.)
I have been hopping around to different locations on Earth in "Sky" mode many times the past two weeks for our intro Astronomy classes. What I have done is create user Surface Locations for the North Pole, Tucson, Equator (Quito), and Santiago de Chile and define the azimuth angle the same for all locations so that the cardinal points stay at the same location in our theater. One can right-click on the Surface Location and select "jump to" within Sky mode and you go right to that location without ever leaving the ground. (However, I tend to select "fly to" since I believe leaving the ground and flying to
various locations on the Earth's surface give the audience a better sense of where they are going.)
Tom
In addition to creating a number of preset Surface Locations, as suggested by Thomas, you can also use the custom commands camera.flyto location ... or camera.jumpto location ... to move to a specified surface location. See the run-time syntax document for more info on parameters for these There's also a command camera.instantjumpto location <long> <lat> which apparently is omitted from the documentation. It works in the same way as the other two, but without fade/fly transition.
On the GUI side, you also have the possibility to fly/jump directly to a specified location without having to create a Surface Location. To do this, in the Navigation tool, click on the name of the location (if you haven't gone to a to a specific surface location, it will simply say "Location"). Clicking on it brings up a pop up window where you can type in a location and then choose to fly or jump there.
And yes, we're putting together a show on celestial navigation right now. It'd be great to be able to build commands that let us smoothly slide up towards the pole or the equator while in sky mode, rather than just jumping between them.
You can indeed specify location by name. The commands for this are camera.jumpto namedlocation ... and camera.flyto namedlocation ... . You specify the location by providing the path to the actual surface location file, rather than the name seen in the library. This is to avoid naming conflicts. Here's an example:
Note that you need to start the path with application/data/ rather than the absolute path on your system. Also, all spaces need to be replaced by %20.
Regarding your other question about being able to slide across the surface to a new location without leaving the surface, this is currently not supported via any command. If you think it's important, however, I'll be happy to add it to our list of feature requests.
Cheers,
Per
Sorry, forgot that part. To go to user-added locations, the command looks like this:
camera.flyto location -122.4662 37.7707 (CAS, which I notice is not on the list of Uniview installs!) it flies me to somewhere around Indiana, whereas if I do
camera.jumpto location -122.4662 37.7707 it correctly takes me to the Academy.
In our Digital Earth presentations, we have a lot of flight very close to the surface of the Earth. We like to have the cardinal points marker on, because it is easy for audiences as well as speaker and navigator get disoriented in unfamiliar terrain.
Even for star talks, I tend not to use Sky mode, since the virtual horizon is not horizontal in our tilted dome. And when you move the camera over the surface of the Earth to change latitude or longitude in Sky mode, the surface of the Earth is not visible. The audience doesn't have that additional cue to show that they are moving.
And to demonstrate how migrating birds navigate, it's useful for the audience to be able to see the ground that the birds are flying over. This is actually a great example of an early interdisciplinary use of a planetarium. Researchers determined that some birds look for the rise and set motions of stars in the sky over the course of the night, and use that information to head north or south, depending on the season. These discoveries were made with experiments using birds in cages in planetariums in the 1970s (!), and I've used Uniview to show these results for an ornithology class in the past.
I prefer the Earth navigation in Orbit mode over that in the Surface mode. For the former, I can smoothly mimic airplane-like flight with LMB and Ctrl+CMB. With practice, I get excellent looking flights through valleys or past mountain ranges, or pivoting around a mountain peak. In my limited experience with Sky mode however, Shift+LMB (interspersed with awkward shifts to using Ctrl+CMB) results in far clunkier motions.
But regardless of whether you prefer Orbit or Surface modes, the grids and markers should appear in both in addition to the Sky mode. (Obviously the grids would have to fade in and out in Orbit mode depending on distance from the Earth, the same way they did in 1.5.)