A plant growth simulation model was developed based on a diffusion-limited aggregation (DLA)
model, which was modified by taking into account the influence of a light stimulus. The plant structure
and the direction of growth were determined by adjusting the two parameters, α and θ, which control the
strength and the direction of light, respectively. The simulation results showed that virtual plant growth
can respond to the light source. The plant growth tended toward the light source in a designed direction
between 60 and 120°.