1. Plants as Hierarchies of Objects
CS 658
“Invasion” by Giles Tran at Plants from xFrog

2. Objectives Practice reading and understanding a paper
Explain difference between p-graphs and i-trees.
Given a p-graph, construct the i-tree
Compare and contrast L-systems with Lintermann’s approach.
Reason about how Lintermann’s approach might be made adaptive to a given environment.

3. What problem are they trying to solve?
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

4. Who cares and why?
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

5. What have others done and why is that inadequate?
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

6. What have others done and why is that inadequate?
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

7. What are they going to do to solve the problem?
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

8. P-graph and I-graph prototype graph
which is traversed to produce the I, or instance graph.
instance graph

9. P-graphs and I-trees
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

10. Multiplication in Nodes
Geometry with multiplication built-in
Just multiplication

11. Geometry Nodes
Geometry
Geometry with multiplication built-in

12. Plants as Hierarchies
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

13. Plants as Hierarchies
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

14. Plants as Hierarchies
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

15. Plants as Hierarchies
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

16. Simple Example

17. Simple Example

18. Simple Example

19. Simple Example

20. Another Example
From Lintermann and Deussen, “Interactive modeling of plants” in IEEE Computer Graphics and Applications, Jan/Feb 1999

21. Examples
Gilles Tran at

22. Questions As intuitive as procedural methods?
As powerful as L-systems?
How would you make it adaptive in a given environment?
Competition for light?
Competition for space?
Wind?