Examples and co-simulation¶

Run a C++ demo¶

From the repository root, after configuring as described in Installation:

cmake --build build --target DEMdemo_SingleSphereCollide --config Release
cd build
./bin/DEMdemo_SingleSphereCollide

On Windows, use bin/Release/DEMdemo_SingleSphereCollide.exe for a multi-configuration Release build. Demos can create output files in the working directory. Read each source file’s introductory comments for inputs, output, and any prerequisite terrain preparation.

SingleSphereCollide, MeshCollide, and MeshFalling use the interactive viewer when it is enabled. See Interactive visualization for responsive loop patterns, the recommended PoC/small-scale scope, and simulation-throughput tradeoffs.

Choose a starting point¶

All demo sources live under src/demo/; the target names below have the prefix DEMdemo_. The checked-in src/demo/CMakeLists.txt lists the available demo targets.

Topic	Demo targets (omit the `DEMdemo_` prefix here)
Installation check	`SingleSphereCollide`
Clump-based mixing	`Mixer`
Mesh particle contact and motion	`MeshCollide`, `MeshFalling`, `DrumCubes`, `MixerCubes`
Analytical and meshed cylinder contacts	`HopperSphereCylinder`, `HopperSphereMeshedCylinder`
Prescribed boundary motion	`Centrifuge`, `Sieve`
Granular experiments	`BallDrop`, `ConePenetration`, `RotatingDrum`, `Repose`, `Plow`
Terrain preparation and wheel tests	`GRCPrep_Part1`, `GRCPrep_Part2`, `GRCPrep_Part3`, `WheelDP`, `WheelDPSimplified`, `WheelSlopeSlip`
Additional properties and custom force models	`Indentation`, `Electrostatic`, `FractureBox`
Prescribed mesh deformation and force extraction	`FlexibleMesh`
Nonstandard applications	`GameOfLife`

WheelDP needs a prepared terrain checkpoint; WheelDPSimplified is a starting point without that prerequisite. Electrostatic illustrates forces that act without physical overlap. FractureBox uses contact wildcards for bonds and breakage. FlexibleMesh prescribes deformation; it does not include a solid-mechanics solver.

For Python, start with Python quickstart and the runnable files under docs/python/examples/. Use examples from this checkout with its matching extension: older scripts on the historical pyDEME_demo branch can use different APIs.

Co-simulation¶

DEME handles granular dynamics and exposes forces and body state to external solvers. Coupled applications can use another solver for joints, motors, controllers, or deformable-body mechanics. See Retrieving simulation data for host and CUDA-array exchange and Installation for installing the C++ library.

The historical feature/DEME branch of projectchrono/chrono-projects contains Chrono coupling examples. Those examples target their corresponding Chrono/DEME revisions and may need porting to this branch. Their CMake setup uses Chrono_DIR, ENABLE_PROJECTS=ON, ENABLE_DEME_TESTS=ON, and DEME_DIR after both libraries are installed.