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- High-speed 3-D animation for IBM PC/XT/AT/PS-2 computers
- Jack M. Loomis and David W. Eby
- Department of Psychology
- University of California, Santa Barbara CA 93106
-
- Hardware requirements: MS-DOS or PC-DOS IBM type-computer with 640K of
- RAM, CGA-capability (e.g., CGA, EGA, or VGA). RGB monitor highly
- recommended.
-
- Start-up requirement: No ram-resident utility (ramdisk or program) should
- be installed when running this software, for memory interference will
- result.
-
- The two programs OBJECT and AUTOMOVE allow one to create and move 3-D
- objects about within 3-D space. The objects (e.g., torus, cylinder, helix,
- cube, ellipsoid) are defined by points positioned randomly on their
- surfaces. The motion editor (AUTOMOVE) permits one to move up to 4 objects
- about in space; the motion can be any combination of linear translation and
- rotation (about an arbitrary fixed axis). Each frame of an animation
- sequence consists of a perspective projection of the moving object. For
- those with color monitors, objects can be projected in any of 3 colors
- using the 320x200 CGA graphics mode. On 8 MHz 80286 machines, animation of
- frames consisting of up to 600 points each is possible at rates of up to 60
- frames/sec. To achieve this speed, the frames of the animation sequence
- are first computed and stored in RAM and then played back from RAM. These
- programs were developed to permit study of the visual perception of 3-D
- shape from motion, but they may be useful to anyone interested in doing
- high-speed 3-D animation. They are surprisingly effective displays.
- The two programs provided here are the object editor, OBJECT.EXE, and
- the motion editor, AUTOMOVE.EXE. You can use the object editor to create
- your own objects (we suggest objects with 256 points) or you can use three
- pre-made objects (with .OBT extension) as inputs to AUTOMOVE. When you
- execute AUTOMOVE, you will see that there are two modes of operation:
- automatic and manual. In the automatic mode, you select one of three
- objects and one of two motions and an animation sequence is automatically
- created and displayed. In the manual mode, you can input any object you
- might have created using OBJECT.EXE and then select parameters for moving
- it about in space. To give you an idea of how to use the motion editor
- manually, we will take you through creation of an animation sequence using
- the object DOGMOT.OBT as an input (DOGMOT is a difference-of-gaussians).
- When you execute AUTOMOVE, select option 1 (load objects), enter 1 (# of
- objects), type in DOGMOT (without extension) as the name of the object, and
- enter 256 for the number of points. When the program returns to the main
- menu, you may select options 2 or 3 to review or change the default
- parameters. Option 2 sets the projection plane distance and position of
- the image on the screen. Option 3 sets the image scale factors for your
- particular video display. For now, we recommend that you do not alter the
- default values. Instead, select Option 4. Clear 2 segments of memory (of
- 64K each) beginning at segment 4. Then select 170 frames. Choose your
- object to be whatever color you wish (use 3 if you have a monochrome
- monitor). Then choose the starting and ending coordinates both to be
- 0,0,400 (there will be no translation of the object). If you wish, you can
- alter the starting orientation of the object, but for now we suggest that
- you specify no change. Finally, specify a rotation that is about an axis
- with X, Y, and Z axis components. We suggest proportions of .4, .4 and .2
- (the last is computed for you since the three proportions add up to 1).
- Finally, select 360 for a full rotation. If you have entered all values
- correctly, respond to the final prompt with "y". After all 170 frames have
- been created (and stored in memory), the program returns to the main menu.
- Select Option 6 to display the sequence. Specify a starting segment of 4,
- 256 points, 170 frames, 1 raster scan per frame, and 10 times through the
- sequence. If you like what you saw, you can save the animation sequence
- using Option 5.
- The animation routines were developed in assembly language and are
- callable from BASIC or Turbo Pascal. The 3-D object and motion programs
- were created in BASIC. Besides the compiled versions provided here, we
- have versions that run under the interpreter (BASIC or GWBASIC) as well.
- All assembler and BASIC source code and executable programs (on a 360K
- disk), a 1.2M disk of animation demonstrations (for faster machines with
- RGB displays), a published article and 16 page manual are available by
- sending a $6 check (made out to the Regents of the University of
- California) to the first author (Loomis) at the above address. The $6
- charge is for the cost of disks, duplication, and postage. Allow up to 2
- weeks for us to respond.
-
- Reference: Loomis, J.M. & Eby, D.W. High-speed animation on the IBM
- PC/XT/AT. Behavior Research Methods, Instruments, and Computers, 1987, 19,
- 10-18.
-