Description

Continuum representation SPH deformable terrain model.

#include <SPHTerrain.h>

Inheritance diagram for chrono::vehicle::SPHTerrain:

Collaboration diagram for chrono::vehicle::SPHTerrain:

Public Member Functions
	SPHTerrain (ChSystem &sys, double spacing)
	Create a granular SPH terrain object. More...

void	SetVerbose (bool verbose)
	Enable verbose output during construction of SPHTerrain (default: false).

fsi::ChSystemFsi &	GetSystemFSI ()
	Access the underlying FSI system.

void	AddRigidObstacle (const std::string &obj_file, double scale, double density, const ChContactMaterialData &cmat, const ChFrame<> &pos, const ChVector<> &interior_point=ChVector<>(0))
	Add a rigid obstacle. More...

void	Construct (const std::string &sph_file, const std::string &bce_file, const ChVector<> &pos=ChVector<>(0), double yaw_angle=0)
	Construct a granular SPH terrain object using information from the specified files. More...

void	Construct (double length, double width, double depth, int bce_layers=3, const ChVector<> &pos=ChVector<>(0), double yaw_angle=0, bool side_walls=true)
	Construct a rectangular patch granular SPH terrain object of given dimensions. More...

void	Construct (const std::string &heightmap_file, double length, double width, const ChVector2<> &height_range, double depth, int bce_layers=3, const ChVector<> &pos=ChVector<>(0), double yaw_angle=0, bool side_walls=true)
	Construct a granular SPH terrain object from a given heightmap. More...

void	Initialize ()
	Initialize the terrain. More...

std::shared_ptr< ChBody >	GetGroundBody () const
	Get the ground body.

void	GetAABB (ChVector<> &aabb_min, ChVector<> &aabb_max) const
	Get the AABB of terrain SPH particles.

void	SaveMarkers (const std::string &out_dir) const
	Save the set of SPH and BCE grid locations to the files in the specified output directory.

virtual void	Synchronize (double time) override
	Update the state of the terrain system at the specified time.

virtual double	GetHeight (const ChVector<> &loc) const override
	Get the terrain height below the specified location.

virtual chrono::ChVector	GetNormal (const ChVector<> &loc) const override
	Get the terrain normal at the point below the specified location.

virtual float	GetCoefficientFriction (const ChVector<> &loc) const override
	Get the terrain coefficient of friction at the point below the specified location. More...

Public Member Functions inherited from chrono::vehicle::ChTerrain
virtual void	Advance (double step)
	Advance the state of the terrain system by the specified duration.

virtual void	GetProperties (const ChVector<> &loc, double &height, ChVector<> &normal, float &friction) const
	Get all terrain characteristics at the point below the specified location.

void	RegisterHeightFunctor (std::shared_ptr< HeightFunctor > functor)
	Specify the functor object to provide the terrain height at given locations. More...

void	RegisterNormalFunctor (std::shared_ptr< NormalFunctor > functor)
	Specify the functor object to provide the terrain normal at given locations. More...

void	RegisterFrictionFunctor (std::shared_ptr< FrictionFunctor > functor)
	Specify the functor object to provide the coefficient of friction at given locations.

Additional Inherited Members
Protected Attributes inherited from chrono::vehicle::ChTerrain
std::shared_ptr< HeightFunctor >	m_height_fun
	functor for location-dependent terrain height

std::shared_ptr< NormalFunctor >	m_normal_fun
	functor for location-dependent terrain normal

std::shared_ptr< FrictionFunctor >	m_friction_fun
	functor for location-dependent coefficient of friction

Constructor & Destructor Documentation

◆ SPHTerrain()

chrono::vehicle::SPHTerrain::SPHTerrain	(	ChSystem &	sys,
		double	spacing
	)

Create a granular SPH terrain object.

No SPH parameters are set.

Member Function Documentation

◆ AddRigidObstacle()

void chrono::vehicle::SPHTerrain::AddRigidObstacle	(	const std::string &	obj_file,
		double	scale,
		double	density,
		const ChContactMaterialData &	cmat,
		const ChFrame<> &	pos,
		const ChVector<> &	interior_point = `ChVector<>(0)`
	)

Add a rigid obstacle.

A rigid body with visualization and collision geometry read from the Wavefront OBJ file is created at the specified position and with the specified orientation. BCE markers are created with the separation value specified at construction. Must be called before Initialize().

Parameters

obj_file	Wavefront OBJ file name
scale	scale factor
density	material density
cmat	contact material properties
pos	obstacle position in absolute frame
interior_point	point inside obstacle volume

◆ Construct() [1/3]

void chrono::vehicle::SPHTerrain::Construct	(	const std::string &	heightmap_file,
		double	length,
		double	width,
		const ChVector2<> &	height_range,
		double	depth,
		int	bce_layers = `3`,
		const ChVector<> &	pos = `ChVector<>(0)`,
		double	yaw_angle = `0`,
		bool	side_walls = `true`
	)

Construct a granular SPH terrain object from a given heightmap.

The image file is read with STB, using the number of channels defined in the input file and reading the image as 16-bit (8-bit images are automatically converted). Supported image formats: JPEG, PNG, BMP, GIF, PSD, PIC, PNM. Create the SPH particle grid locations for a terrain patch of specified X and Y dimensions with optional translation and rotation. The height at each grid point is obtained through bilinear interpolation from the gray values in the provided heightmap image (with pure black corresponding to the lower height range and pure white to the upper height range). SPH particle grid locations are generated to cover the specified depth under each grid point. BCE marker layers are created below the bottom-most layer of SPH particles and (optionally) on the sides of the terrain patch.

Parameters

heightmap_file	filename for the heightmap image
length	patch length (X direction)
width	patch width (Y direction)
height_range	height range (black to white level)
depth	soil depth
bce_layers	number of BCE layers
pos	patch center
yaw_angle	patch yaw rotation
side_walls	create side boundaries

◆ Construct() [2/3]

void chrono::vehicle::SPHTerrain::Construct	(	const std::string &	sph_file,
		const std::string &	bce_file,
		const ChVector<> &	pos = `ChVector<>(0)`,
		double	yaw_angle = `0`
	)

Construct a granular SPH terrain object using information from the specified files.

The SPH particle and BCE marker locations are assumed to be provided on an integer grid. Locations in real space are generated using the specified grid separation value and the terrain patch translated and rotated aboutn the vertical.

Parameters

sph_file	filename with SPH grid particle positions
bce_file	filename with BCE grid marker positions
pos	patch center
yaw_angle	patch yaw rotation

◆ Construct() [3/3]

void chrono::vehicle::SPHTerrain::Construct	(	double	length,
		double	width,
		double	depth,
		int	bce_layers = `3`,
		const ChVector<> &	pos = `ChVector<>(0)`,
		double	yaw_angle = `0`,
		bool	side_walls = `true`
	)

Construct a rectangular patch granular SPH terrain object of given dimensions.

Parameters

length	patch length (X direction)
width	patch width (Y direction)
depth	patch depth (Z direction)
bce_layers	number of BCE layers
pos	patch center
yaw_angle	patch yaw rotation
side_walls	create side boundaries

◆ GetCoefficientFriction()

virtual float chrono::vehicle::SPHTerrain::GetCoefficientFriction ( const ChVector<> & loc ) const

inlineoverridevirtual

Get the terrain coefficient of friction at the point below the specified location.

This coefficient of friction value may be used by certain tire models to modify the tire characteristics, but it will have no effect on the interaction of the terrain with other objects (including tire models that do not explicitly use it).

Reimplemented from chrono::vehicle::ChTerrain.

◆ Initialize()

void chrono::vehicle::SPHTerrain::Initialize ( )

Initialize the terrain.

After this call, no additional solid bodies should be added to the FSI problem.

The documentation for this class was generated from the following files:

/builds/uwsbel/chrono/src/chrono_vehicle/terrain/SPHTerrain.h
/builds/uwsbel/chrono/src/chrono_vehicle/terrain/SPHTerrain.cpp

Description

Public Member Functions

Additional Inherited Members

Constructor & Destructor Documentation

◆ SPHTerrain()

Member Function Documentation

◆ AddRigidObstacle()

◆ Construct() [1/3]

◆ Construct() [2/3]

◆ Construct() [3/3]

◆ GetCoefficientFriction()

◆ Initialize()