Description

Utilities for Bullet-based collision detection.

Classes
class	ChConvexHullLibraryWrapper
	Wrapper for using and exporting the Bullet implementation of the convex hull library. More...

Functions
btVector3	ProjectPointOnLine (const btVector3 &lP, const btVector3 &lD, const btVector3 &P)
	Project point onto line. More...

btScalar	DistancePointToLine (const btVector3 &lP, const btVector3 &lD, const btVector3 &P)
	Calculate distance from point to line. More...

int	SnapPointToBox (const btVector3 &hdims, btVector3 &loc)
	Snap the specified location to a point on a box with given half-dimensions. More...

bool	PointInsideBox (const btVector3 &hdims, const btVector3 &loc)
	Check if given point is inside box (point expressed in box frame). More...

int	FindClosestBoxFace (const btVector3 &hdims, const btVector3 &loc)
	Find the closest box face to the given point (expressed in box frame). More...

bool	IntersectSegmentBox (const btVector3 &hdims, const btVector3 &c, const btVector3 &a, const btScalar hlen, const btScalar tol, btScalar &tMin, btScalar &tMax)

bool	IntersectLinePlane (const btVector3 &lP, const btVector3 &lD, const btVector3 &pP, const btVector3 &pN, const btScalar tol, btScalar &t)
	Utility function to intersect a line with a plane Plane equation: pN.X = pN.pP Line equation: X = lP + t * lD Solution: t = pN. More...

bool	IntersectSegmentCylinder (const btVector3 &sC, const btVector3 &sD, const btScalar sH, const btVector3 &cC, const btVector3 &cD, const btScalar cH, const btScalar cR, const btScalar tol, btScalar &tMin, btScalar &tMax)
	Utility function to intersect a segment with a cylinder. More...

Function Documentation

◆ DistancePointToLine()

ChApi btScalar chrono::collision::bt_utils::DistancePointToLine	(	const btVector3 &	lP,
		const btVector3 &	lD,
		const btVector3 &	P
	)

Calculate distance from point to line.

Parameters

lP	point on line
lD	line direction (unit vector)
P	point

◆ FindClosestBoxFace()

ChApi int chrono::collision::bt_utils::FindClosestBoxFace	(	const btVector3 &	hdims,
		const btVector3 &	loc
	)

Find the closest box face to the given point (expressed in box frame).

Returns +1, +2, +3 (for a "positive" face in x, y, z, respectively) or -1, -2, -3 (for a "negative" face).

Parameters

hdims	box half-dimensions
loc	point

◆ IntersectLinePlane()

ChApi bool chrono::collision::bt_utils::IntersectLinePlane	(	const btVector3 &	lP,
		const btVector3 &	lD,
		const btVector3 &	pP,
		const btVector3 &	pN,
		const btScalar	tol,
		btScalar &	t
	)

Utility function to intersect a line with a plane Plane equation: pN.X = pN.pP Line equation: X = lP + t * lD Solution: t = pN.

(pP-lP) / pN.lD

Parameters

lP	point on line
lD	line direction (unit vector)
pP	point on plane
pN	plane normal (unit vector)
tol	tolerance for orthogonality test
t	line parameter of intersection point

◆ IntersectSegmentBox()

ChApi bool chrono::collision::bt_utils::IntersectSegmentBox	(	const btVector3 &	hdims,
		const btVector3 &	c,
		const btVector3 &	a,
		const btScalar	hlen,
		const btScalar	tol,
		btScalar &	tMin,
		btScalar &	tMax
	)

Parameters

hdims	box half-dimensions
c	segment center point
a	segment direction (unit vector)
hlen	segment half-length
tol	tolerance for parallelism test
tMin	segment parameter of first intersection point
tMax	segment parameter of second intersection point

◆ IntersectSegmentCylinder()

ChApi bool chrono::collision::bt_utils::IntersectSegmentCylinder	(	const btVector3 &	sC,
		const btVector3 &	sD,
		const btScalar	sH,
		const btVector3 &	cC,
		const btVector3 &	cD,
		const btScalar	cH,
		const btScalar	cR,
		const btScalar	tol,
		btScalar &	tMin,
		btScalar &	tMax
	)

Utility function to intersect a segment with a cylinder.

Segment assumed to be parameterized as sP = sC + t * sD, with -sH <= t <= sH. Cylinder given by its center cC, axis direction cD, halh-lengh cH, and radius cR. Assume |sD| = |cD| = 1. (1) Find tMin and tMax where the segment supporting line intersects cylindrical surface by finding points on segment at a distance cR from the cylinder axis line. (2) Clamp result to cylinder end-caps. (3) Clamp result to segment length.

Parameters

sC	segment center point
sD	segment direction (unit vector)
sH	segment half-length
cC	cylinder axis center
cD	cylinder axis direction (unit vector)
cH	cylinder axis half-length (cylinder halh-height)
cR	cylinder radius
tol	tolerance for parallelism test
tMin	segment parameter of first intersection point
tMax	segment parameter of second intersection point

◆ PointInsideBox()

ChApi bool chrono::collision::bt_utils::PointInsideBox	(	const btVector3 &	hdims,
		const btVector3 &	loc
	)

Check if given point is inside box (point expressed in box frame).

Parameters

hdims	box half-dimensions
loc	point

◆ ProjectPointOnLine()

ChApi btVector3 chrono::collision::bt_utils::ProjectPointOnLine	(	const btVector3 &	lP,
		const btVector3 &	lD,
		const btVector3 &	P
	)

Project point onto line.

Parameters

lP	point on line
lD	line direction (unit vector)
P	point

◆ SnapPointToBox()

ChApi int chrono::collision::bt_utils::SnapPointToBox	(	const btVector3 &	hdims,
		btVector3 &	loc
	)

Snap the specified location to a point on a box with given half-dimensions.

The in/out location is assumed to be specified in the frame of the box (which is therefore assumed to be an AABB centered at the origin). The return code indicates the box axes that caused snapping:

first bit (least significant) corresponds to x-axis
second bit corresponds to y-axis
third bit corresponds to z-axis

Therefore: code = 0 indicates an interior point code = 1 or code = 2 or code = 4 indicates snapping to a face code = 3 or code = 5 or code = 6 indicates snapping to an edge code = 7 indicates snapping to a corner

Parameters

hdims	box half-dimensions
loc	point (in/out)

Description

Classes

Functions

Function Documentation

◆ DistancePointToLine()

◆ FindClosestBoxFace()

◆ IntersectLinePlane()

◆ IntersectSegmentBox()

◆ IntersectSegmentCylinder()

◆ PointInsideBox()

◆ ProjectPointOnLine()

◆ SnapPointToBox()