L-system Tree
For my 3D Computer Graphics course in 2010, I had to create a procedural model as an assignment. We decided to make a tree using L-systems. After a few daws of coding, the result of this assignment is a program which can draw procedural trees using OpenGL. Although OpenGL is nowadays an oldfashioned 3D drawing technique, the result looks quite pretty.
Three rules that are executed, with probabilities 1.0, 0.5 and 0.5 for execution each iteration. As input only the first character is used. You can use the following characters:
- F
- Draws a branch of length L (this length depends on scale and iteration index)
- -
- Determine elevation with zenith - θ
- +
- Determine elevation with zenith + θ
- (
- Increment drawing direction of azimuth φ
- )
- Decrement drawing direction of azimuth φ
- [
- Opens a subtree (iteration function will be recursively invoked
- ]
- Closes a subtree
Seed is the initial string. The seed is used als input for the rules in the first iteration. Only the first entered character will be used.
The parameters are to change the shape of the tree. When using different min and max values, the program uses a uniform chosen value between these two values.
The Generate button makes a new three using the inserted rules and parameters. Draw leaves shows utterly beautiful triangular leaves at the branches that were created in the last iteration
The Play and Stop buttons start/stop the tree from rotating.
The Reset button resets all input fields to the initial state and clears the screen. Quit closes the windows and exits the program.
