WEBSITE AND WEBSITE GRAPHICS CREATED WITH XARA DESIGNER 6 PRO
Because the rings are rotating around a common axis, the first and last
rings are lined up adjacent to each other, with the front of the first ring
lined up against the back of the last ring, and even a tiny error shows up
as a visible gap or lip. So not only did the sizing pixels have to be
accurately positioned, the ring centres had to be very carefully aligned
onto the sizing pixel’s mutual centre. Using Xara Xtreme’s Guide lines
and rotation centres of the shapes at extreme magnification made this
pretty easy to do.
This was a lot of effort just to be able to use 150 rings.
So, was it worth it?
Spinning the Hollow Earth - Animation
Xara 3D has animation tools, but there is a limitation; only one
animation type can be used at any one time. So since I used the Swing
animation in the Hollow Earth to move the rings into position, I no
longer can use the Rotate animation to spin it, and still keep it as a
globe. This is more an inconvenience than anything else, because it is
still perfectly possible to spin the Hollow Earth, it just has to be done
manually.
This is done by changing the viewpoint in Xara 3D and taking a screen
shot, placing it into an animation frame in Xara Xtreme, then advancing
the viewpoint a set number of degrees and repeating the cycle, building
up the required series of such frames. When done, each frame can be
cropped, and an animated GIF can be exported.
More frames means more work and a larger file size, but also smoother
animation. I bit the bullet to create the smoothest animation with a full
360 frames, with a viewpoint shift of 1° per frame. Xara 3D doesn’t let
you change the viewpoint less than 1 degree at a time (thank
goodness!). But once I have the all these frames in Xara Xtreme, and the
file saved, I can export the full 360 frames, or delete every second
frame and export 180 frames, or delete every 2nd, 3rd and 4th frame,
and export 90 frames, and so on.
Partial Swing Angles
One last little detail, and we are done. With 150 rings to be swung, the
required Swing angle is 2.4° for the 2nd ring, 4.8° for the next, and so
on. Unfortunately, Swing doesn’t let you set fractional degrees, so I
could set 2° or 3° but not 2.4°. With 2° increments, there would be a
gap because the rings wouldn’t swing enough to reach all the way
around the equator, and with 3° increments, the last several rings would
overshoot beyond the first few rings. I got round this by not letting
Swing run to its maximum extent, but I needed to pinpoint which frame
to pause on.
As the Swing animation runs, it starts off with no Swing, then the rings
start spreading out around the equator in one direction, slowing down as
they approach maximum swing at frame 64, then reversing back to no
Swing at frame 128 and carrying on in the reverse direction around the
equator to hit the opposite maximum at frame 196, and then returning
to no Swing at frame 256.
By measuring the amount of Swing of a single line against a calibrated
background, I identified frame 39 as being 80% of full Swing. I could set
the Swing angles in 3° increments, and by pausing the animation at
frame 39, the rings only achieve 80% of their potential maximum. 80% of
3°= 2.4°. Thus the rings close properly when the animation is paused on
frame 39 of 256. And thank goodness, it was so!
I hope you enjoyed this account of the Making of the Hollow Earth, and
found useful tidbits of information in it. Click here to see a larger
version of the animation. The file is about 5MB so be patient. It takes a
minute to download and play.
Mike Sims
Send e-mail
H 1 2 3 4 5 6 Download Zipped Tutorial
Because the rings are rotating around a common axis, the first and last
rings are lined up adjacent to each other, with the front of the first ring
lined up against the back of the last ring, and even a tiny error shows up
as a visible gap or lip. So not only did the sizing pixels have to be
accurately positioned, the ring centres had to be very carefully aligned
onto the sizing pixel’s mutual centre. Using Xara Xtreme’s Guide lines
and rotation centres of the shapes at extreme magnification made this
pretty easy to do.
This was a lot of effort just to be able to use 150 rings.
So, was it worth it?
Spinning the Hollow Earth - Animation
Xara 3D has animation tools, but there is a limitation; only one
animation type can be used at any one time. So since I used the Swing
animation in the Hollow Earth to move the rings into position, I no
longer can use the Rotate animation to spin it, and still keep it as a
globe. This is more an inconvenience than anything else, because it is
still perfectly possible to spin the Hollow Earth, it just has to be done
manually.
This is done by changing the viewpoint in Xara 3D and taking a screen
shot, placing it into an animation frame in Xara Xtreme, then advancing
the viewpoint a set number of degrees and repeating the cycle, building
up the required series of such frames. When done, each frame can be
cropped, and an animated GIF can be exported.
More frames means more work and a larger file size, but also smoother
animation. I bit the bullet to create the smoothest animation with a full
360 frames, with a viewpoint shift of 1° per frame. Xara 3D doesn’t let
you change the viewpoint less than 1 degree at a time (thank
goodness!). But once I have the all these frames in Xara Xtreme, and the
file saved, I can export the full 360 frames, or delete every second
frame and export 180 frames, or delete every 2nd, 3rd and 4th frame,
and export 90 frames, and so on.
Partial Swing Angles
One last little detail, and we are done. With 150 rings to be swung, the
required Swing angle is 2.4° for the 2nd ring, 4.8° for the next, and so
on. Unfortunately, Swing doesn’t let you set fractional degrees, so I
could set 2° or 3° but not 2.4°. With 2° increments, there would be a
gap because the rings wouldn’t swing enough to reach all the way
around the equator, and with 3° increments, the last several rings would
overshoot beyond the first few rings. I got round this by not letting
Swing run to its maximum extent, but I needed to pinpoint which frame
to pause on.
As the Swing animation runs, it starts off with no Swing, then the rings
start spreading out around the equator in one direction, slowing down as
they approach maximum swing at frame 64, then reversing back to no
Swing at frame 128 and carrying on in the reverse direction around the
equator to hit the opposite maximum at frame 196, and then returning
to no Swing at frame 256.
By measuring the amount of Swing of a single line against a calibrated
background, I identified frame 39 as being 80% of full Swing. I could set
the Swing angles in 3° increments, and by pausing the animation at
frame 39, the rings only achieve 80% of their potential maximum. 80% of
3°= 2.4°. Thus the rings close properly when the animation is paused on
frame 39 of 256. And thank goodness, it was so!
I hope you enjoyed this account of the Making of the Hollow Earth, and
found useful tidbits of information in it. Click here to see a larger
version of the animation. The file is about 5MB so be patient. It takes a
minute to download and play.
Mike Sims
Send e-mail
H 1 2 3 4 5 6 Download Zipped Tutorial