Hierarchical animation using trigonometric functions:
This program was written in C++ for my Computer Graphics
MSc assignment. It is a simulation where a varying number
of robots made by transformed cubes walk in different
directions without collisions. The robot parts are parts
of a transformation hierarchy. Trigonometric functions are
used for the animation.
Robot Construction - Hierarchy
The robot parts are part of a hierarchy tree:
Each robot part is a cube scaled and transformed to have the desired size and position.
It is then rotated around a point (pivot), whose position is calculated relatively to its parent pivot point position.
The hierarchy tree.
The robot is animated using trigonometric functions. Their output is restricted to match the rotation angles of the human
The total transformation of each part consists of its transformation parameters
concatenated with its parent transformation. In essence, while rendering the
robot we traverse the hierarchy multiplying transformations as we go down the
Number of animated robots
The program was extended to support an arbitrary number of animated robots.
The robots are walking in circles with different radii and offsets. Hence, there are
no collisions between them and they look like running in random points around
the circuimference. The scene (a children room) is resized automatically to
account for the number of robots running around in order to avoid collisions
with the walls as you can see in figures 4 and 5.
The code can be downloaded from here
It runs on Linux, BSD, MacOSX.
Extract and cd the directory
Type $ make
To run it on Linux/BSD type ./bob <number_of_robots> on Mac OS X it's just: bob <number_of_robots>