Figure 7: Four plants generated by the same stochastic L-system
definition
In the L-systems mentioned in Section 
and Section ,
all plants generated by the same L-system and geometry definitions are identical,
while in reality there is no plant in the world growing in the same way.
Does God play dice? Einstein did not believe it, but simulating natural process
by using probability is at least a much simpler approach before underlying
natural rules are discovered. In our project, we implemented a stochastic L-system.
We may have several rules for one symbol, and we choose a specific rule
according to its probability distribution.
If we generate many virtual plants in a garden, all plants will have different
appearance though they are based on the same stochastic L-system definition. It
is a great approximation to nature scene.
The L-system definition in text file r3.l:
There are three production rules available whenever symbol F is
to be replaced(the float numbers inside the braces denote probabilities),
so we can
generate surprisingly large amounts of different plants from
this single stochastic L-system definition. The plants in Figure
are only four of the possible plants(images (i), (ii), (iii), and (iv)).
The geometry definition:
We can see clearly the branches of the plants in this
example sprouting leaves. The leaves are originally set
red on the screen to fit the season when I was writing
the code of this software.