chrono::collision::ChCollisionModel Class Reference

#include <CHcCollisionModel.h>

Inheritance diagram for chrono::collision::ChCollisionModel:

List of all members.

Public Member Functions
virtual int	ClearModel ()=0
virtual int	BuildModel ()=0
virtual bool	AddSphere (double radius, ChVector<> *pos=0)=0
virtual bool	AddEllipsoid (double rx, double ry, double rz, ChVector<> *pos=0, ChMatrix33<> *rot=0)=0
virtual bool	AddBox (double hx, double hy, double hz, ChVector<> *pos=0, ChMatrix33<> *rot=0)=0
virtual bool	AddCylinder (double rx, double rz, double hy, ChVector<> *pos=0, ChMatrix33<> *rot=0)=0
virtual bool	AddConvexHull (std::vector< ChVector< double > > &pointlist, ChVector<> *pos=0, ChMatrix33<> *rot=0)=0
virtual bool	AddTriangleMesh (const geometry::ChTriangleMesh &trimesh, bool is_static, bool is_convex, ChVector<> *pos=0, ChMatrix33<> *rot=0)=0
virtual bool	AddBarrel (double Y_low, double Y_high, double R_vert, double R_hor, double R_offset, ChVector<> *pos=0, ChMatrix33<> *rot=0)=0
virtual bool	AddCopyOfAnotherModel (ChCollisionModel *another)=0
virtual bool	AddConvexHullsFromFile (ChStreamInAscii &mstream, ChVector<> *pos=0, ChMatrix33<> *rot=0)
virtual ChPhysicsItem *	GetPhysicsItem ()=0
virtual void	SyncPosition ()=0
virtual void	SetFamily (int mfamily)=0
virtual int	GetFamily ()=0
virtual void	SetFamilyMaskNoCollisionWithFamily (int mfamily)=0
virtual void	SetFamilyMaskDoCollisionWithFamily (int mfamily)=0
virtual bool	GetFamilyMaskDoesCollisionWithFamily (int mfamily)=0
virtual void	SetSafeMargin (double amargin)
virtual float	GetSafeMargin ()
virtual void	SetEnvelope (double amargin)
virtual float	GetEnvelope ()
virtual ShapeType	GetShapeType ()
virtual void	GetAABB (ChVector<> &bbmin, ChVector<> &bbmax) const =0
virtual void	StreamIN (ChStreamInBinary &mstream)
virtual void	StreamOUT (ChStreamOutBinary &mstream)
Static Public Member Functions
static void	SetDefaultSuggestedEnvelope (double menv)
static void	SetDefaultSuggestedMargin (double mmargin)
static double	GetDefaultSuggestedEnvelope ()
static double	GetDefaultSuggestedMargin ()
Protected Member Functions
virtual float	GetSuggestedFullMargin ()
Protected Attributes
float	model_envelope
float	model_safe_margin
ShapeType	model_type

---

Detailed Description

Class containing the geometric model ready for collision detection. Each rigid body will have a ChCollisionModel. A ChCollisionModel will contain all the geometric description(s) of the shape of the rigid body, for collision purposes.

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Member Function Documentation

virtual bool chrono::collision::ChCollisionModel::AddBarrel	(	double	Y_low,
		double	Y_high,
		double	R_vert,
		double	R_hor,
		double	R_offset,
		ChVector<> *	pos = 0,
		ChMatrix33<> *	rot = 0
	)		[pure virtual]

Add a barrel-like shape to this model (main axis on Y direction), for collision purposes. The barrel shape is made by lathing an arc of an ellipse around the vertical Y axis. The center of the ellipse is on Y=0 level, and it is ofsetted by R_offset from the Y axis in radial direction. The two radii of the ellipse are R_vert (for the vertical direction, i.e. the axis parellel to Y) and R_hor (for the axis that is perpendicular to Y). Also, the solid is clamped with two discs on the top and the bottom, at levels Y_low and Y_high.

Implemented in chrono::collision::ChModelBullet.

virtual bool chrono::collision::ChCollisionModel::AddBox	(	double	hx,
		double	hy,
		double	hz,
		ChVector<> *	pos = 0,
		ChMatrix33<> *	rot = 0
	)		[pure virtual]

Add a box shape to this model, for collision purposes.

Parameters:

hx	the halfsize on x axis
hy	the halfsize on y axis
hz	the halfsize on z axis
pos	the position of the box COG
rot	the rotation of the box - matrix must be orthogonal

Implemented in chrono::collision::ChModelBullet.

virtual bool chrono::collision::ChCollisionModel::AddConvexHull	(	std::vector< ChVector< double > > &	pointlist,
		ChVector<> *	pos = 0,
		ChMatrix33<> *	rot = 0
	)		[pure virtual]

Add a convex hull to this model. A convex hull is simply a point cloud that describe a convex polytope. Connectivity between the vertexes, as faces/edges in triangle meshes is not necessary. Points are passed as a list, that is instantly copied into the model.

Implemented in chrono::collision::ChModelBullet.

bool chrono::collision::ChCollisionModel::AddConvexHullsFromFile	(	ChStreamInAscii &	mstream,
		ChVector<> *	pos = 0,
		ChMatrix33<> *	rot = 0
	)		[virtual]

Add a cluster of convex hulls by a '.chulls' file description. The file is an ascii text that contains many lines with "[x] [y] [z]" coordinates of the convex hulls. Hulls are separated by lines with "hull". Inherited classes should not need to implement/overload this, because this base implementation basically calls AddConvexHull() n times while parsing the file, that is enough.

virtual bool chrono::collision::ChCollisionModel::AddCopyOfAnotherModel

(

ChCollisionModel *

another

)

[pure virtual]

Add all shapes already contained in another model. If possible, child classes implement this so that underlying shapes are shared (not copied) among the models.

Implemented in chrono::collision::ChModelBullet.

virtual bool chrono::collision::ChCollisionModel::AddEllipsoid	(	double	rx,
		double	ry,
		double	rz,
		ChVector<> *	pos = 0,
		ChMatrix33<> *	rot = 0
	)		[pure virtual]

Add an ellipsoid shape to this model, for collision purposes.

Parameters:

rx	the rad on x axis
ry	the rad on y axis
rz	the rad on z axis
pos	the position of the ellipsoid
rot	the matrix defining rotation (orthogonal)

Implemented in chrono::collision::ChModelBullet.

virtual bool chrono::collision::ChCollisionModel::AddSphere	(	double	radius,
		ChVector<> *	pos = 0
	)		[pure virtual]

Add a sphere shape to this model, for collision purposes.

Parameters:

radius	the radius of the sphere
pos	the position of the sphere in model coordinates

Implemented in chrono::collision::ChModelBullet.

virtual bool chrono::collision::ChCollisionModel::AddTriangleMesh	(	const geometry::ChTriangleMesh &	trimesh,
		bool	is_static,
		bool	is_convex,
		ChVector<> *	pos = 0,
		ChMatrix33<> *	rot = 0
	)		[pure virtual]

Add a triangle mesh to this model, passing a triangle mesh (do not delete the triangle mesh until the collision model, because depending on the implementation of inherited ChCollisionModel classes, maybe the triangle is referenced via a striding interface or just copied) Note: if possible, in sake of high performance, avoid triangle meshes and prefer simplified representations as compounds of convex shapes of boxes/spheres/etc.. type. See functions above.

Parameters:

trimesh	the triangle mesh
is_static	true only if model doesn't move (es.a terrain). May improve performance
is_convex	true if mesh convex hull is used (only for simple mesh). May improve robustness
rot	displacement respect to COG (optional)

Implemented in chrono::collision::ChModelBullet.

virtual int chrono::collision::ChCollisionModel::BuildModel

(

)

[pure virtual]

Builds the BV hierarchy. Call this function AFTER adding the geometric description. MUST be inherited by child classes! (ex for bulding BV hierarchies)

Implemented in chrono::collision::ChModelBullet.

virtual int chrono::collision::ChCollisionModel::ClearModel

(

)

[pure virtual]

Deletes all inserted geometries. Also, if you begin the definition of a model, AFTER adding the geometric description, remember to call the ClearModel(). MUST be inherited by child classes! (ex for resetting also BV hierarchies)

Implemented in chrono::collision::ChModelBullet.

virtual void chrono::collision::ChCollisionModel::GetAABB	(	ChVector<> &	bbmin,
		ChVector<> &	bbmax
	)		const [pure virtual]

Returns the axis aligned bounding box (AABB) of the collision model, i.e. max-min along the x,y,z world axes. Remember that SyncPosition() should be invoked before calling this. MUST be implemented by child classes!

Implemented in chrono::collision::ChModelBullet.

virtual bool chrono::collision::ChCollisionModel::GetFamilyMaskDoesCollisionWithFamily

(

int

mfamily

)

[pure virtual]

Tells if the family mask of this collision object allows for the collision with another collision object belonging to a given family. NOTE: this function has NO effect if used before you add the body to a ChSystem, using AddBody(). Use after AddBody().

Implemented in chrono::collision::ChModelBullet.

virtual ChPhysicsItem* chrono::collision::ChCollisionModel::GetPhysicsItem

(

)

[pure virtual]

Gets the pointer to the client owner ChPhysicsItem. MUST be implemented by child classes!

Implemented in chrono::collision::ChModelBulletNode, chrono::collision::ChModelBulletParticle, chrono::collision::ChModelBulletBody, and chrono::collision::ChModelBulletDEM.

virtual void chrono::collision::ChCollisionModel::SetEnvelope

(

double

amargin

)

[virtual]

Sets the suggested collision outward 'envelope' (used from shapes added, from now on, to this collision model). This 'envelope' is a surrounding invisible volume which extends outward from the surface, and it is used to detect contacts a bit before shapes come into contact, i.e. when dist>0. However contact points will stay on the true surface of the geometry, not on the external surface of the envelope. Side effect: AABB are 'expanded' outward by this amount, so if you exagerate with this value, CD might be slower and too sensible. On the other hand, if you set this value to 0, contacts are detected only for dist<=0, thus causing unstable simulation.

virtual void chrono::collision::ChCollisionModel::SetFamily

(

int

mfamily

)

[pure virtual]

By default, all collsion objects belong to family n.0, but you can set family in range 0..15. This is used when the objects collided with another: the contact is created only if the family is within the 'family mask' of the other, and viceversa. NOTE: these functions have NO effect if used before you add the body to a ChSystem, using AddBody(). Use after AddBody(). MUST be implemented by child classes!

Implemented in chrono::collision::ChModelBullet.

virtual void chrono::collision::ChCollisionModel::SetFamilyMaskNoCollisionWithFamily

(

int

mfamily

)

[pure virtual]

By default, family mask is all turned on, so all families can collide with this object, but you can turn on-off some bytes of this mask so that some families do not collide. When two objects collide, the contact is created only if the family is within the 'family mask' of the other, and viceversa. NOTE: these functions have NO effect if used before you add the body to a ChSystem, using AddBody(). Use after AddBody(). MUST be implemented by child classes!

Implemented in chrono::collision::ChModelBullet.

virtual void chrono::collision::ChCollisionModel::SetSafeMargin

(

double

amargin

)

[virtual]

Sets the suggested collision 'inward safe margin' for the shapes to be added from now on, using the AddBox, AddCylinder etc (where, if this margin is too high for some thin or small shapes, it may be clamped).. If dist<0 and interpenetation occurs (ex.for numerical errors) within this 'safe margin' inward range, collision detection is still fast and reliable (beyond this, for deep penetrations, CD still works, but might be slower and less reliable) Side effect: think at the margin as a radius of a 'smoothing' fillet on all corners of the shapes - that's why you cannot exceed with this...

void chrono::collision::ChCollisionModel::StreamIN

(

ChStreamInBinary &

mstream

)

[virtual]

Method to allow deserializing a persistent binary archive (ex: a file) into transient data.

Reimplemented in chrono::collision::ChModelBullet.

void chrono::collision::ChCollisionModel::StreamOUT

(

ChStreamOutBinary &

mstream

)

[virtual]

Method to allow serializing transient data into a persistent binary archive (ex: a file).

Reimplemented in chrono::collision::ChModelBullet.

virtual void chrono::collision::ChCollisionModel::SyncPosition

(

)

[pure virtual]

Sets the position and orientation of the collision model as the rigid body current position. MUST be implemented by child classes!

Implemented in chrono::collision::ChModelBulletNode, chrono::collision::ChModelBulletParticle, chrono::collision::ChModelBulletBody, and chrono::collision::ChModelBulletDEM.