Interactive authoring of simulation-ready plants

Abstract

Figure 1: Simulation of a peach tree with anatomically realistic geometry (Prunus Persica), with fracture. Peaches fall from the tree swaying in the space-time Perlin wind. 299,707 triangles, 237 branches, 3,556 twigs, 18,536 leaves, 330 fruits, 2,950 reduced DOFs, 7 hierarchy levels, 5 msec of simulation per graphical frame. AbstractPhysically based simulation can produce quality motion of plants, but requires an authoring stage to convert plant "polygon soup" triangle meshes to a format suitable for physically based simulation. We give a system that can author complex simulation-ready plants in a manner of minutes. Our system decomposes the plant geometry, establishes a hierarchy, builds and connects simulation meshes, and detects instances. It scales to anatomically realistic geometry of adult plants, is robust to non-manifold input geometry, gaps between branches or leaves, free-flying leaves not connected to any branch, spurious geometry, and plant self-collisions in the input configuration. We demonstrate the results using a FEM model reduction simulator that can compute large-deformation dynamics of complex plants at interactive rates, subject to user forces, gravity or randomized wind. We also provide plant fracture (with prespecified patterns), inverse kinematics to easily pose plants, as well as interactive design of plant material properties. We authored and simulated over 100 plants from diverse climates and geographic regions, including broadleaf (deciduous) trees and conifers, bushes and flowers. Our largest simulations involve anatomically realistic adult trees with hundreds of branches and over 100,000 leaves.

Interactive wood combustion for botanical tree models

“…Recent approaches provide more nuanced ways to efficiently model branching structures with an emphasis on simulating the response of trees to their environment , interactive growth or FEM simulation [Zhao and Barbič 2013]. Longay et al [2012] introduce an interactive tree modeling system that jointly models trees based on the competition for resources and user defined sketches.…”

A simulation on grass swaying with dynamic wind force

“…The trees and grass are different in structure and thus require a different model to simulate the behavior of grass motion under wind forces. FEM-based simulation is another method to solve the interaction between wind and plants [13,30]. Among those different approaches of wind modeling mentioned above, for performance consideration, we adopt the Eulerian grid-based approach to better fit in our grass dynamics simulation with proposed grass model in this paper.…”

Analyzing growing plants from 4D point cloud data

“…Recently, Zhao and Barbič [2013] proposed a technique to interactively author plant models to be simulation-ready by decomposing the polygon soup into domains and building a hierarchy between them. While it is very challenging and often ambiguous to automatically segment plants into individual organs from isolated plant models, we demonstrate that such segmentation can be robustly extracted from a raw 4D point cloud, making the resultant models directly useable by their simulation framework, and thus providing a complementary way to generate simulation-ready models.…”

“…Cross frame organ information transfer identifies these two leaves and provides correct information for realistic simulation (right). The image is courtesy of [Zhao and Barbič 2013].…”