This is not an official blogpost. It is only supportive material for our ICLR 2022 submission Boundary Graph Neural Networks for 3D Simulations.

# BGNN Example Trajectories

## Overview

- Models with a Cohesive Material
- Models with a Non-Cohesive Material
- Failures
- Out-of Distribution (OOD) Experiments

## Models with a Cohesive Material

### Drum

Successful trial of training a BGNN for a cohesive material within a rotating drum (250.000 simulation time steps):

### Hopper

Successful trial of training a BGNN for a cohesive material within a hopper device (100.000 simulation time steps):

## Models with a Non-Cohesive Material

### Drum

Successful trial of training a BGNN for a non-cohesive material within a rotating drum (250.000 simulation time steps):

### Hopper

Successful trial of training a BGNN for a non-cohesive material within a hopper device (100.000 simulation times teps):

## Failures

### Drum

Failure trial of training a BGNN for a cohesive material within a rotating drum (250.000 simulation time steps):

### Hopper

Failure trial of training a BGNN for a cohesive material within a hopper device (100.000 simulation time steps):

### Comment on Failures

Local (small) modeling errors of particle-wall interactions result in a leak in the wall and some particles incorrectly cross the wall, whereafter many other particles follow through the leak

## Out-of Distribution (OOD) Experiments

### Drum

The upper animation below shows a typical training example, while the animation directly beneath is an OOD example. For OOD test samples the length of the cylinder has increased compared to training and test samples.

### Hopper

The upper animation below shows a typical training example, while the animation directly beneath is an OOD example. For OOD test samples the outlet hole size has decreased and the inclination angle has increased.