Description
There exist numerous claims that prehistorical and historical buildings have been built so that important architectural elements (main axes, windows, ...) are pointing into astronomically relevant directions, e.g. cardinal points (due North, South, East, West) or points where the Sun rises at the solstices, or where certain stars appeared/vanished on the horizon at some point in time, etc.
Surveyors can measure the horizon elevations, and astronomers can compute positions of respective celestial objects, but for members of other disciplines and a wider audience these things remain hard to understand. Virtual reconstructions and demonstrations can help to verify, and later to communicate these ideas to a wider audience.
There exist many archaeologically correct virtual reconstructions of ancient buildings, in which the user can walk around and get an impression of the old architecture. There also exist a few astronomically correct desktop planetarium programs, where the night sky can be explored from a single location on Earth. However, a high-quality simulation of the night sky combined with a landscape and building walkthrough seems to be missing.
Task
Stellarium is an OpenSource multiplatform (Windows, Mac, Linux) desktop planetarium program providing a quite realistic view of day and night skies, and several uncommon features like dome rendering, telescope control, or the possibility to exchange constellation figures (great for ethno-astronomical demonstrations). The local horizon can be shown with a panorama photograph, giving a pretty good feeling of immersion, restricted however to one observer location. It does not only use the typical rectangular viewport, but also allows super-wideangle views in several projections.
In a previous "Praktikum", a plugin was developed allowing a 3D walkthrough of virtual landscapes in OBJ format. So far, only simple textured models are supported. Missing features include:- shadow mapping. A partial solution has been implemented, but needs improvements or a rewrite. Light sources to consider are obviously the sun, at nighttimes the moon, and without any of the two, the planet Venus. Only 1 shadowing lightsource is active.
- A switchable ambient illumination to illuminate the foreground scenery.
- higher quality OBJ models may include bump or normal maps for added realism. Add support for those.
Stellarium has been chosen by the European Space Agency as one of the supported projects in their Summer of Code in Space 2011 programmes . In order to receive funding for your work, you should also implement a few of the tasks listed on the Stellarium site. We propose you add improvements in planet and comet rendering, as they are related to the tasks for the 3D plugin listed above. Coding Timeframe: August-October 2011.
During the walkthrough, interesting viewpoints shall be stored, so that they can be retrieved at later sessions.
Tools
Stellarium is an OpenSource project at Launchpad. Its sources are available directly from the BZR repository there.
Several example landscapes in .obj format will be provided for testing.
Requirements
C++, OpenGL experience is helpful. Development should be done on Windows or Linux. Given the expected user base, Windows is preferred in this case. Note that Stellarium is a multiplatform project, so optimally your plugin should work on all 3 platforms. A Stellarium key developer has signalled interest and his will to support you.
At least casual interest in visual astronomy (skywatching) may be helpful to understand Stellarium and to like this project, but is no obligation.
Note that this project shall be contributed to the Stellarium project, so a successful project may bring you international applause, and will be something probably used by many thousands of users worldwide.
