Procedural Tree Modeling with Silhouette Constraints

Modeling trees is known to be a difficult problem in computer graphics. At Animal Logic, the typical artist workflow involves using the in-house tool for semi-procedural tree generation. The artists hand model trunk, branch, and leaf geometry, and trees are generated by scattering branches and leaves in a recursive manner.

This approach has several limitations. First, artists often would like to hit a certain silhouette or shape of a tree, represented with closed mesh volumes. While this is possible with the existing approach by culling branches that leave the volumes, this results in an unnatural appearance, as if the tree had been manually trimmed. Second, the approach does not prevent intersections between branches during the recursive addition of branches. Such cases are undesirable and result in an unrealistic appearance of generated trees.

The aim of this project is to develop a method for semi-procedural tree generation that generates a tree defined within mesh volumes using artist modeled trunk, branch, and leaf geometry in a manner consistent with artist expectations. Our approach will significantly reduce the time artists spend manually creating trees that fit a certain shape; as a result, large collections of trees can be constructed with reduced manual intervention.

Faculty Supervisor:

Alla Sheffer

Student:

Partner:

Animal Logic Studios (Vancouver) Ltd.

Discipline:

Computer science

Sector:

Information and cultural industries

University:

The University of British Columbia

Program: