Already a few weeks ago, a colleague drew my attention to a couple of new papers on interactive self-adapting botanical tree models, published by the computer visualization group in Konstanz, who had also presented at Siggraph 2011 (see my previous post about Siggraph). This new development in procedural modeling techniques makes tree models possible that will interact with their environment! For example, if you insert a building, the surrounding trees will change their shape and branches will give way to the new object in a most realistic way.
How are these astonishing results achieved? Input is a skeleton-based tree geometry. In contrast to traditional tree growing models, the new technique approximates biologically motivated transformations. Main factor is the light distribution and the amount of resources a tree receives. On that basis, the growth rate for the entire tree and individual branches as well as branch ages are calculated. A complex illumination model makes sure that light conditions are updated for different stages of tree growth. Additional factors are phototropism and gravitropism and I was surprised how realistic the outcomes look.
Because the approach does not require the tree model to be reconstructed from the beginning, it performs much better than previous approaches and is even suitable for real-time applications. That means, you could insert an object such as a building but also other trees and experiment in real-time how the surrounding trees might change their growth in response to each other and inanimate objects.
For more information and the original research paper, please see
SIGGRAPH 2012:
http://graphics.uni-konstanz.d
SIGGRAPH Asia 2012:
http://graphics.uni-konstanz.d