Controllable Modular Trees
Proceedings of the 51st Graphics Interface Conference, 2025
Abstract
Trees are a ubiquitous part of virtual environments, but faithfully modeling trees is challenging because of their incredible diversity. Tree modeling methods face two key challenges, as users want to create trees that look realistic but retain control over key elements of their appearance, such as the shape of the tree crowns. Traditional tree modeling methods are geared to produce tree models that are both detailed and unique and are typically stored as high-triangle count meshes or skeletons plus radii. Storing and manipulating such traditional tree models comes with a significant memory cost. Recent approaches have proposed to use modular trees consisting of a finite set of branch modules, which are transformed (scaled, translated, and rotated) to jointly form realistic looking trees. Consequently, modular trees require orders of magnitude less memory than their traditional counterparts. However, existing methods for modeling modular trees focus on visual realism and provide only minimal mechanisms for artists to control the look and shape of the resulting trees. We propose a controllable method for modeling modular trees, enabling artists to define the tree's overall crown shape while maintaining a plausible appearance using a small set of replicated branch modules. We formulate the computation of realistic modular trees that conform to a user-specified crown shape as a constrained mixed-variable optimization problem. We then compute the trees that satisfy these constraints using a method that grows trees one layer of branches at a time, maintaining realism throughout and promoting accurate approximation of the target crown shape. We extensively test our method on diverse crown shapes and compare against baselines, demonstrating its effectiveness.
Paper
Results
Comparisons of our modular trees (e) against baselines enforcing a subset of our constraints (a-d).
Producing multiple modular trees with a different number of branch modules while maintaining the same crown shape.
Unique tree shapes and different types of branch modules.
BibTex
@inproceedings{takikawa25modulartrees,
author = {Takikawa, Suzuran and Tinchelli, Riccardo and Davison, Mike and Andrus, Curtis and Drown, James and Sheffer, Alla},
title = {Controllable Modular Trees},
booktitle = {Proceedings of the 51st Graphics Interface Conference},
year = {2025},
numpages = {10},
location = {Kelowna, BC, Canada},
series = {GI '25}
}