The Sprite Gallery
Posted: Fri Dec 26, 2008 6:38 pm
My sprite experiments ended up as a small, spooky age.
This is meant only to add to the Wiki sprite description.
The sprite types are represented by the value (in D'ni) of the least-significant, four bits of the sprite flags.
Sprite 1 keeps its current Y axis aligned to the camera's view of its original Z axis. It is well-behaved near the equator of the original Z axis.
Sprite 2 takes the ray in the original XY plane that is aligned with the camera's view of the original Z axis and aligns that current ray to the camera's view of the original Z axis.
It is well-behaved near the zenith and nadir of the original Z axis.
Sprite 4 aligns the current Y axis with the original Y axis. It is well-behaved near the equator.
Sprite 8 does not impose any alignment. It is well-behaved at all angles. Since arbitrary rotations aren't orthogonal the sprite's orientation is dependent on its rotation history.
The sprite displays in the gallery limit the views to well-behaved geometries. You can see sprite 8 from many angles, but sprite 2 only from angles near the zenith of its original Z axis. The original Z axis points up.
Enjoy the gallery and let me know if any or all of this is nonsense!
This is meant only to add to the Wiki sprite description.
The sprite types are represented by the value (in D'ni) of the least-significant, four bits of the sprite flags.
Sprite 1 keeps its current Y axis aligned to the camera's view of its original Z axis. It is well-behaved near the equator of the original Z axis.
Sprite 2 takes the ray in the original XY plane that is aligned with the camera's view of the original Z axis and aligns that current ray to the camera's view of the original Z axis.
It is well-behaved near the zenith and nadir of the original Z axis.
Sprite 4 aligns the current Y axis with the original Y axis. It is well-behaved near the equator.
Sprite 8 does not impose any alignment. It is well-behaved at all angles. Since arbitrary rotations aren't orthogonal the sprite's orientation is dependent on its rotation history.
The sprite displays in the gallery limit the views to well-behaved geometries. You can see sprite 8 from many angles, but sprite 2 only from angles near the zenith of its original Z axis. The original Z axis points up.
Enjoy the gallery and let me know if any or all of this is nonsense!