Parametric Architecture – Botanical Treeson Cad

PARAMETRIC ARCHITECTURE – MY THESIS JUNE 1993

Creating botanical trees on AutoCAD

Thesis goals

Joint venture between the chair of computer graphics at the Technical University of Munich, department of computer science and AcadGRAPH.

Create 3D botanical trees on AutoCAD Provide interface to change tree parameters and

define new tree types Simulate tree growth

The size of the tree needs to be accurate Single tree species must be differentiable Several growth stages / ages need to be

represented Use botanical, forestry statistics and growth

curves (cross-discipline)

Algorithm: L-Systems

Lindenmayer systems can create organic shapes as well as strictly geometric ones.It all depends on the angles.

Algorithm: L-system applied

Write a recursive grammar for the movements of a 3D “turtle” moving in space according to angles &(a), ^(b), +(d) and repeat until maximum branching level has been reached.Note: trees usually branch once a year, but nature curtails them to a maximum branching level determined by the environment.This grammar, however, could be used indefinitely.

Fibonacci in nature (leaf variations) Leaves / branch configurations follow the Fibonacci sequence

Spiral configuration Cross branch configuration

Alternating configuration

Interface

Type in “Baum” (German for tree) at AutoCAD command prompt, tree interface will come up.Select tree type, type in age, toggle leaves on or off, pick drawing level

Select drawing level:LineCylinderConeHyperbolic curvesTopsy-turvy cone

shape

Interface continued

To craft your own tree either from imagination or based on real data:

Edit tree interfaceSpecify new tree

parameters such as angle, branch/branch length and width rations, angle contraction rate, tree maximum life expectancy, etc.Specify leaves, Specify environmental factors such as: gravitational parameter, wind direction and strength, etc.

Interface continued

Craft your own leaves in a 3D modeling program, then use “edit leaf” interface to associate 3D leaf with tree and build a branch structure.Use interface to switch to AutoCAD drawing mode, bend, mirror, draw leaf and display in perspective

Fun Pictures / Variations

Fun pictures / variations continued

One program / many shapes

Questions?