The Mars rovers have several cameras that come in pairs, just like human eyes, to capture images in stereo. The Midnight Planets app features the ability to view most of these images in stereo 3D, in several different formats. Some of these options for 3D do not even need special glasses, although they may require a little practice to use. So instead of just looking around on Mars, with surprising little effort you might be able to look around on Mars in 3D. If you can do it - and many people can - the effort will be well rewarded.
The vision modes in Midnight Planets are found in the View Options menu.
This option shows the left images for stereo cameras. (For monoscopic cameras, it simply shows the images.)
This options shows the right images for stereo cameras.
This option combines the left and right views into a red-cyan anaglyph, which is viewed using red-cyan 3D glasses (the most common kind of colored 3D glasses).
This option shows a section of the left and right views side-by-side. If you relax your eyes a bit, it is possible to get your left eye to look at the left view, and your right eye to look a the right view; at that magic point, the two views “merge” into a single view in 3D. This is a great way to view in 3D because the view is very sharp, it preserves the color of the images, and it does not require any special glasses.
Full Screen Stereogram
This option is similar to “Freeviewing Stereogram”, but uses the whole screen (or window), showing the left view in the left half and the right view in the right half. On the iPad Mini, this larger size may be preferable. On the Mac, this option is often not useful for viewing in 3D; it is provided more for browsing both left and right images at the same time. On the iPhone and iPod Touch, this option is identical to “Freeviewing Stereogram” and so is not included.
This option is similar to Freeviewing Stereogram but reverses the left and right eyes. Some people prefer this method of viewing, but unforunately the author can’t explain it, because he’s never been able to do it himself.
This option was to support the “my3D” stereogram device for iPhone and iPod Touch, or other physical stereogram devices. At the time of writing, the my3D does not support iPhone 5 or newer iPod Touch with 4" screen, so the author has not fully developed this option.
3D TV Side-By-Side Output
This option is currently only available on the Mac. It is used by directing the screen output to a 3D TV. The Midnight Planets view should be in full screen mode.
Some tips for viewing in 3D in Midnight Planets:
Start with a wide view toward the horizon. At the time of writing, the app has some issues projecting images in the foreground close to the rover; fixing that will require more math than the author has time for at the moment. There are some similar issues when the rover is parked at an incline. Keep your eyes level with the screen… unless the left-right projection is obviously askew, in which case it might help to tilt your head a bit one way or the other.
For the Freeviewing options, it may help to remove your glasses if you wear them. It may take some work to find the distance between your eyes and the screen that allows your eyes to focus on the separate left and right views. Once you’ve learned the trick of freeviewing, it gets much easier.
Switching ground-relative viewing to OFF in the View Options may help somewhat with viewing some challenging targets in stereo. Normally you’ll want to view with the ground relative view option turned ON.
The different stereo cameras on the rovers are separated by different distances, creating a different stereo ‘depth’. Usually the separation is greater than that of human eyes, so the stereo effect may be exaggerated.
Curiosity’s Mastcam was not exactly intended to provide stereo, since the left and right cameras have different focal lengths and fields of view (the right camera is sort of the ‘zoom lens’). Never the less, Mastcam images work fairly well in stereo, when all the images are combined into a panoramic view. It may help to select a particular image that you are looking at. Where both Mastcam eyes are not available, often Mastcam can visually combine with Navcam images in the app to produce a stereo effect.