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: http://star.arm.ac.uk/impact-hazard/animation/asteroid3.html
Дата изменения: Thu Sep 2 19:15:03 2010 Дата индексирования: Tue Oct 2 06:43:04 2012 Кодировка: Поисковые слова: m 2 |
After the initial flyby we have 6 minutes before anything interesting happens - we still want to keep everything in real time but just following it with our simple chase camera will be rather boring. To this end I created a few other cameras to provide some alternate views of the descent.
In some of the shots the Sun creeps into view - particularly during the sunset sequence. The old 'lens flare' cliché is the best way to give the impression that the Sun is as bright as it is so I used the NKFlare plugin from Povray. This looks very nice despite my reservations about something so clichéd but until you can do images with much higher colour resolution it's probably the only way to give a suitable impression of what the Sun looks like.
Also for the sunset, I add a dust halo around the planet stretching up 50km about its surface so that the edge of the planet can be seen illuminated and so that we can see the asteroid as it too passes below the horizon - since the Sun is in our field of view it won't illuminate the dark side of the asteroid and all we see is the shadow where it covers more distant features. The dust halo takes up a lot of rendering time so it is usually deactivated - it would be nice to have it enabled during the final descent and impact but the number of light sources required would make this unfeasibly slow.
Of course adding lens flare to the Sun means that it will need to be added in some fashion to the light emitted by the asteroid. This is easy enough for point events like explosions but the light emmited by the shocked air in the tail will be more difficult to model.
but that'll be handled later.....
Other camera angles added include a shot from inside the asteroid's path watching it fly towards us and away from us while sitting still - this shot is very rapid. There are two orbiting cameras in different planes - one to show the Earth and the other to show the Sun being eclipsed by the asteroid.
All the image sequences are cut together using a little script which lets me blend between frames from different directories and produce a single output sequence.
An example showing the dark side of the asteroid and the Sun with lens flare
Last sunset for the asteroid
Last Revised: 2009 November 10th |