Background is animated from Terragen (http://planetside.co.uk)
, (using Terranim, a path animator designed for use with Terragen, (http://terranim.cjb.net))
The animated background was created at a resolution of 320x240 and consist of 1084 frames in the form of individual bitmap files. (This example contains only 96 frames to keep the size reasonable. Full version will eventually become a screensaver with music). (NOTE: The background of 1084 images took 3 days to render).
The project window is set up to create an animation at 30 fps with 1084 frames (or however many frames you are using).
The aircraft model was created in Strata at position 0,0,0 (x,y,z coordinates, units in pixels). A camera was created at (0,0, -2880) that faced the aircraft from the rear. (I wanted to display the back of the aircraft as it flies through the background which is why the z position is negative). The size of the camera window was adjusted to 320x240 (1.33:1). Note: The camera is never moved. This ensures the background is always rendered in the correct position.
Next, a new background cubic was created and applied to the environment. The first BMP file of the background animation was loaded as the “Front” image of the cubic with the frame rate set to 30fps (use front image for all sides is checked). Strata will automatically render the appropriate background image for that particular frame # in the rendered animation. The coverage of the image was set with vertical coverage = 9.34% and horizontal coverage = 12.44% which worked fine for the resolution I’m using. If you use a different resolution ratio for the Strata camera or for the background images, you will need to play with the coverage values.
I attempted to use the same method initially for setting the backdrop image, but the frame rates didn’t quite display correctly.
The "work around" was to use Flash to create another set of bitmaps.
I created a new Flash animation setting the document to 320x240 at a frame rate of 30 fps. I then loaded the background images and then exported the movie as a Bitmap Sequence under a different name as the original, (of course).
I could then load the first of these new images as the camera backdrop with proper syncing.
(A suggestion for future Strata update: Allow fps setting in the backdrop image dialog box)
Now the tedious part:
I went through the entire animation and set the proper position of the aircraft at key frames in the animation. I also had to adjust the position of the single global light in order to mimic the correct position of the “sun” as the background changed. To aid in this, I “encapsulated” the aircraft with a large sphere so I could easily compare the shadows from the global light with that of the background. After I was finished adjusting the global light position, I deleted the sphere.
Rendered (All) in Raytracing as an SWF file. I loaded this file into Flash to add some actionscript and reduced the framerate to 24 fps.
A longer (but smaller sized) version can be viewed at; http://www.dan-j-moore.com/3d/strata/flash.asp?getimage=100