ACM Transactions on Graphics (Proceedings of SIGGRAPH Asia), 2014

Windy Trees: Computing Stress Response for Developmental Tree Models

Sören Pirk1,2       Till Niese2       Torsten Hädrich2
Bedrich Benes3       Oliver Deussen2

1ESRI R&D Center Zurich, Switzerland
2University of Konstanz, Germany
3Purdue University, USA


We present a novel method for combining developmental tree models with turbulent wind fields. The tree geometry is created from internal growth functions of the developmental model and its response to external stress is induced by a physically-plausible wind field that is simulated by Smoothed Particle Hydrodynamics (SPH). Our tree models are dynamically evolving complex systems that (1) react in real-time to high-frequent changes of the wind simulation; and (2) adapt to long-term wind stress. We extend this process by wind-related effects such as branch breaking as well as bud abrasion and drying. In our interactive system the user can adjust the parameters of the growth model, modify wind properties and resulting forces, and define the tree's long-term response to wind. By using graphics hardware, our implementation runs at interactive rates for moderately large scenes composed of up to 20 tree models.





 author     = {Pirk, S\"{o}ren and Niese, Till and H\"{a}drich, Torsten 
               and Benes, Bedrich and Deussen, Oliver},
 title      = {Windy Trees: Computing Stress Response for Developmental Tree Models},
 journal    = {ACM Trans. Graph.},
 issue_date = {November 2014},
 volume     = {33},
 number     = {6},
 month      = nov,
 year       = {2014},
 issn       = {0730-0301},
 pages      = {204:1--204:11},
 articleno  = {204},
 numpages   = {11},
 url        = {},
 doi        = {10.1145/2661229.2661252},
 acmid      = {2661252},
 publisher  = {ACM},
 address    = {New York, NY, USA},
 keywords   = {animation, generative tree modeling, interactive procedural modeling, 
               plant growth, simulation, visual models of trees},