/usr/include/SurgSim/Math/TriangleCapsuleContactCalculation-inl.h is in libopensurgsim-dev 0.7.0-5.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 | // This file is a part of the OpenSurgSim project.
// Copyright 2013, SimQuest Solutions Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SURGSIM_MATH_TRIANGLECAPSULECONTACTCALCULATION_INL_H
#define SURGSIM_MATH_TRIANGLECAPSULECONTACTCALCULATION_INL_H
#include "SurgSim/Math/Valid.h"
#include "SurgSim/DataStructures/OptionalValue.h"
namespace SurgSim
{
namespace Math
{
namespace TriangleCapsuleContactCalculation
{
/// Find the point on (positive X side of) ellipse parallel to the given tangent.
/// \tparam T Accuracy of the calculation, can usually be inferred.
/// \tparam MOpt Eigen Matrix options, can usually be inferred.
/// \param tangent The given tangent to this ellipse, whose corresponding point is to be found
/// \param center Center of the ellipse.
/// \param majorAxis, minorAxis The major/minor axes of the ellipse, both of unit length
/// \param majorRadius, minorRadius Major/minor radii of the ellipse
/// \note majorAxis and minorAxis are assumed to be orthogonal to each other.
/// \return The point on the ellipse (in positive x direction) which has the given tangent.
template <class T, int MOpt>
Eigen::Matrix<T, 3, 1, MOpt> pointWithTangentOnEllipse(const Eigen::Matrix<T, 3, 1, MOpt>& center,
const Eigen::Matrix<T, 3, 1, MOpt>& majorAxis,
const Eigen::Matrix<T, 3, 1, MOpt>& minorAxis,
const double majorRadius, const double minorRadius,
const Eigen::Matrix<T, 3, 1, MOpt>& tangent)
{
Eigen::Transform<T, 3, Eigen::Isometry> transform;
transform.translation() = center;
transform.linear().col(0) = majorAxis;
transform.linear().col(1) = minorAxis;
transform.linear().col(2) = majorAxis.cross(minorAxis);
// tangent in local coordinates.
Eigen::Matrix<T, 3, 1, MOpt> localTangent = transform.inverse().linear() * tangent;
// Slope of this tangent
T m = localTangent[1] / localTangent[0];
// Ellipse equation: x*x/a*a + y*y/b*b = 1
// Rewriting ellipse equation in the form, y = f(x): y = sqrt(a*a - x*x) * b / a
// Slope of ellipse: y' = -x*b*b/a*a*y
// This slope is equal to the slope of the localTangent. So, we can solve for x and y.
T x = std::sqrt((m * m * majorRadius * majorRadius * majorRadius * majorRadius) /
(minorRadius * minorRadius + m * m * majorRadius * majorRadius));
T y = (minorRadius / majorRadius) *
std::sqrt(majorRadius * majorRadius - x * x) * ((m > 0.0) ? -1.0 : 1.0);
// Transforming this point into world coordinates.
return transform * Eigen::Matrix<T, 3, 1, MOpt>(x, y, static_cast<T>(0));
}
/// Class used to find the intersection between a triangle and a capsule.
/// \tparam T Accuracy of the calculation, can usually be inferred.
/// \tparam MOpt Eigen Matrix options, can usually be inferred.
template <class T, int MOpt>
class TriangleCapsuleContactCalculation
{
typedef Eigen::Matrix<T, 3, 1, MOpt> Vector3;
typedef Eigen::Matrix<T, 2, 1, MOpt> Vector2;
typedef Eigen::Transform<T, 3, Eigen::Isometry> RigidTransform3;
public:
/// Constructor.
/// \param tv0,tv1,tv2 Vertices of the triangle.
/// \param tn Normal of the triangle, should be normalized.
/// \param cv0,cv1 Ends of the capsule axis.
/// \param cr Capsule radius.
TriangleCapsuleContactCalculation(
const Vector3& tv0, const Vector3& tv1, const Vector3& tv2,
const Vector3& tn,
const Vector3& cv0, const Vector3& cv1,
double cr)
: m_tv0(tv0), m_tv1(tv1), m_tv2(tv2), m_tn(tn),
m_cvTop(cv0), m_cvBottom(cv1), m_cr(cr)
{
m_epsilon = static_cast<T>(Geometry::DistanceEpsilon);
m_distance = distanceSegmentTriangle(cv0, cv1, m_tv0, m_tv1, m_tv2, m_tn,
&m_penetrationPointCapsuleAxis, &m_penetrationPointTriangle);
m_cAxis = m_cvBottom - m_cvTop;
m_cLength = m_cAxis.norm();
m_cAxis = m_cAxis / m_cLength;
if (m_cAxis.dot(tn) > 0.0)
{
m_cvTop = cv1;
m_cvBottom = cv0;
m_cAxis = -m_cAxis;
}
}
/// \return Whether there is an intersection.
bool isIntersecting()
{
return m_distance < (m_cr - m_epsilon);
}
/// Calculate the contact info.
/// \param [out] penetrationDepth The depth of penetration.
/// \param [out] penetrationPointTriangle The contact point on triangle.
/// \param [out] penetrationPointCapsule The contact point on capsule.
/// \param [out] contactNormal The contact normal that points from capsule to triangle.
/// \param [out] penetrationPointCapsuleAxis The point on the capsule axis closest to the triangle.
void calculateContact(T* penetrationDepth, Vector3* penetrationPointTriangle, Vector3* penetrationPointCapsule,
Vector3* contactNormal, Vector3* penetrationPointCapsuleAxis)
{
if (isIntersecting())
{
bool result =
axisAwayFromTriangle() ||
axisPerpendicularToTriangle() ||
axisTouchingTriangle() ||
axisThroughTriangle();
SURGSIM_ASSERT(result) << "At this point, there has to be an intersection.";
*penetrationDepth = m_penetrationDepth;
*penetrationPointTriangle = m_penetrationPointTriangle;
*penetrationPointCapsule = m_penetrationPointCapsule;
*contactNormal = m_contactNormal;
*penetrationPointCapsuleAxis = m_penetrationPointCapsuleAxis;
}
}
private:
/// This function handles the contact data calculation for the case where there is an intersection between the
/// capsule and the triangle, but the capsule axis does not intersect the triangle.
/// \return True, if the axis of the capsule is away from the triangle.
/// \note This function presupposes that isIntersecting() returned true.
bool axisAwayFromTriangle()
{
if (m_distance > m_epsilon)
{
m_contactNormal = m_penetrationPointTriangle - m_penetrationPointCapsuleAxis;
m_contactNormal.normalize();
m_penetrationPointCapsule = m_penetrationPointCapsuleAxis + (m_contactNormal * m_cr);
m_penetrationDepth = m_cr - m_distance;
return true;
}
return false;
}
/// This function handles the contact data calculation for the case where there is an intersection between the
/// capsule and the triangle, and the capsule axis is perpendicular to the triangle.
/// \return True, if the axis of the capsule is perpendicular to the triangle.
/// \note This function presupposes that isIntersecting() returned true and axisAwayFromTriangle() returned false.
bool axisPerpendicularToTriangle()
{
if (std::abs(m_cAxis.dot(m_tn) + 1.0) < m_epsilon)
{
m_penetrationPointCapsule = m_cvBottom - m_tn * m_cr;
m_penetrationPointCapsuleAxis = m_cvBottom;
m_contactNormal = -m_tn;
m_penetrationDepth = (m_tv0 - m_penetrationPointCapsule).dot(m_tn);
return true;
}
return false;
}
/// This function handles the contact data calculation for the case where there is an intersection between the
/// capsule and the triangle, and the capsule axis just touches the triangle.
/// \return True, if the axis of the capsule is just touching triangle.
/// \note This function presupposes that isIntersecting() returned true, axisAwayFromTriangle() returned false,
/// and axisPerpendicularToTriangle() returned false.
bool axisTouchingTriangle()
{
if (m_penetrationPointCapsuleAxis.isApprox(m_cvTop, m_epsilon) ||
m_penetrationPointCapsuleAxis.isApprox(m_cvBottom, m_epsilon) ||
isPointOnTriangleEdge(m_penetrationPointTriangle, m_tv0, m_tv1, m_tv2, m_tn))
{
m_contactNormal = -m_tn;
auto projectionCvBottom = (m_cvBottom + m_tn * (m_tv0 - m_cvBottom).dot(m_tn)).eval();
if (SurgSim::Math::isPointInsideTriangle(projectionCvBottom, m_tv0, m_tv1, m_tv2, m_tn))
{
m_contactNormal = -m_tn;
m_penetrationPointCapsule = m_cvBottom - m_tn * m_cr;
m_penetrationPointCapsuleAxis = m_cvBottom;
}
else
{
farthestIntersectionLineCapsule(m_penetrationPointTriangle, -m_tn,
&m_penetrationPointCapsule, &m_penetrationPointCapsuleAxis);
}
m_penetrationDepth = (m_tv0 - m_penetrationPointCapsule).dot(m_tn);
return true;
}
return false;
}
/// This function handles the contact data calculation for the case where there is an intersection between the
/// capsule and the triangle, and the capsule axis goes through the triangle.
/// \return True, if the axis of the capsule goes through the triangle. Also calculates the contact info.
/// \note This function presupposes that isIntersecting() returned true, axisAwayFromTriangle() returned false,
/// axisPerpendicularToTriangle() returned false, and axisTouchingTriangle() returned false.
bool axisThroughTriangle()
{
if (m_distance != 0.0)
{
return false;
}
// Extruding the triangle along the direction of -tn creates a volume. Clip off the capsule axis that is
// outside of this volume.
Vector3 v[3] = {m_tv0, m_tv1, m_tv2};
Vector3 planeN[4] = {m_tn, (-m_tn.cross(m_tv1 - m_tv0)).normalized(), (-m_tn.cross(m_tv2 - m_tv1)).normalized(),
(-m_tn.cross(m_tv0 - m_tv2)).normalized()};
double planeD[4] = {-m_tv0.dot(planeN[0]), -m_tv0.dot(planeN[1]), -m_tv1.dot(planeN[2]), -m_tv2.dot(planeN[3])};
auto segmentStart = m_cvTop;
auto segmentEnd = m_cvBottom;
size_t j = clipSegmentAgainstTriangle(&segmentStart, &segmentEnd, v, planeN, planeD);
if (j == 0)
{
m_contactNormal = -m_tn;
m_penetrationPointCapsule = m_cvBottom - m_tn * m_cr;
m_penetrationDepth = (m_tv0 - m_penetrationPointCapsule).dot(m_tn);
m_penetrationPointCapsuleAxis = m_cvBottom;
m_penetrationPointTriangle = m_penetrationPointCapsule + m_tn * m_penetrationDepth;
return true;
}
Vector3 deepestPoint = ((segmentStart - segmentEnd).dot(planeN[0]) < 0.0) ? segmentStart : segmentEnd;
Vector3 edgeVertices[2] = {v[(j - 1) % 3], v[j % 3]};
Vector3 triangleEdge = (edgeVertices[1] - edgeVertices[0]).normalized();
// The capsule axis intersects the plane (planeN[j], planeD[j]). First, the capsule is treated as a cylinder.
// Its intersection with this plane is an ellipse. The deepest point on this ellipse along -tn and bounded
// by vectors (edgeVertices[0] -> edgeVertices[0] - tn) and (edgeVertices[1] -> edgeVertices[1] - tn) is found.
Vector3 center = deepestPoint;
Vector3 majorAxis = (triangleEdge * (triangleEdge.dot(m_cAxis)) + m_tn * (m_tn.dot(m_cAxis))).normalized();
double majorRadius = farthestIntersectionLineCylinder(center, majorAxis, &deepestPoint);
SURGSIM_ASSERT(isValid(majorRadius)) << "The major radius of the ellipse should be a valid number.";
if (std::abs(majorAxis.dot(triangleEdge)) > m_epsilon)
{
// majorApex is not the deepest point because the ellipse is angled. The deepest point is between majorApex
// and minorApex on the circumference of the ellipse, and the tangent at that point is parallel to the
// triangleEdge.
auto minorAxis = planeN[j].cross(majorAxis);
double minorRadius = farthestIntersectionLineCylinder(center, minorAxis);
SURGSIM_ASSERT(isValid(minorRadius)) << "The minor radius of the ellipse should be a valid number.";
deepestPoint = pointWithTangentOnEllipse(center, majorAxis, minorAxis, majorRadius, minorRadius,
triangleEdge);
Vector3 result;
if (std::abs(distancePointSegment(deepestPoint, m_cvTop, m_cvBottom, &result) - m_cr) > m_epsilon)
{
// The deepest point is not on the capsule, which means that the capsule end (the sphere) is
// intersecting the triangle edge plane (planeN[j], planeD[j]). The intersection between them is a
// circle. Define a 2D co-ordinate system with the origin at edgeVertices[0], the x-axis as
// triangleEdge, and the y-axis as tn. Transforming the circle to this 2D co-ordinate system, creates a
// circle of radius, r, with its center at x, y. Now the deepest point on this circle is (x, y - r).
Vector3 origin = edgeVertices[0], xAxis = triangleEdge, yAxis = m_tn, zAxis = planeN[j];
double sphereCenterToXYPlane = (m_cvBottom - origin).dot(zAxis);
SURGSIM_ASSERT(m_cr + m_epsilon >= sphereCenterToXYPlane)
<< "The sphere center is too far from the triangle edge plane.";
double circleRadius = std::sqrt(m_cr * m_cr - sphereCenterToXYPlane * sphereCenterToXYPlane);
SURGSIM_ASSERT(isValid(circleRadius))
<< "The radius of the circle of intersection between the sphere and the plane is invalid.";
Vector3 circleCenter = m_cvBottom - zAxis * sphereCenterToXYPlane;
double x = (circleCenter - origin).dot(xAxis);
double y = (circleCenter - origin).dot(yAxis) - circleRadius;
deepestPoint = xAxis * x + yAxis * y + origin;
}
}
// Project deepestPoint on the triangle edge to make sure it is within the edge.
auto edgeLength = (edgeVertices[1] - edgeVertices[0]).norm();
double deepestPointDotEdge = triangleEdge.dot(deepestPoint - edgeVertices[0]);
if (deepestPointDotEdge <= -m_epsilon || deepestPointDotEdge >= edgeLength + m_epsilon)
{
// In this case, the intersection of the cylinder with the triangle edge plane gives an ellipse
// that is close to a triangle corner and the deepest penetration point on the ellipse is
// actually outside the triangle.
// Solution: find the deepest point on the ellipse which projection is still on the triangle.
// For that: Find the corner edgeVertex of the triangle closest to deepestPointDotEdge
// Find the deepest penetration point verifying P - tn*t and the cylinder equation.
// The triangle point to consider is edgeVertices[0] or edgeVertices[1].
Vector3 edgeVertex = (deepestPointDotEdge < 0.0) ? edgeVertices[0] : edgeVertices[1];
double d =
farthestIntersectionLineCapsule(edgeVertex, -m_tn, &deepestPoint, &m_penetrationPointCapsuleAxis);
SURGSIM_ASSERT(isValid(d)) << "There must be a part of the ellipse between the triangle edge at this point";
}
m_contactNormal = -m_tn;
m_penetrationPointCapsule = deepestPoint;
m_penetrationDepth = -m_tn.dot(deepestPoint - m_tv0);
m_penetrationPointTriangle = deepestPoint + m_tn * (m_penetrationDepth);
return true;
}
/// \param lineStart The origin of the line
/// \param lineDir Unit directional vector of the line
/// \param point [out] The point of intersection.
/// \return The distance of the point of intersection from the lineStart.
double farthestIntersectionLineCylinder(const Vector3& lineStart, const Vector3& lineDir, Vector3* point = nullptr)
{
if (!m_cInverseTransform.hasValue())
{
Vector3 j, k;
SurgSim::Math::buildOrthonormalBasis(&m_cAxis, &j, &k);
m_cTransform.translation() = m_cvTop;
m_cTransform.linear().col(0) = m_cAxis;
m_cTransform.linear().col(1) = j;
m_cTransform.linear().col(2) = k;
m_cInverseTransform = m_cTransform.inverse();
}
// Transform the problem in the cylinder space to solve the local cylinder equation y^2 + z^2 = r^2
// Point on ellipse should be on the line, P + t.(D)
// => Py^2 + t^2.Dy^2 + 2.Py.t.Dy + Pz^2 + t^2.Dz^2 + 2.Pz.t.Dz = r^2
// => t^2.(Dy^2 + Dz^2) + t.(2.Py.Dy + 2.Pz.Dz) + (Py^2 + Pz^2 - r^2) = 0
// Let a = (Dy^2 + Dz^2), b = (2.Py.Dy + 2.Pz.Dz), c = (Py^2 + Pz^2 - r^2):
// => t^2.a + t.b + c = 0, whose solution is:
// (-b +/- sqrt(b^2 - 4*a*c))/2*a
auto const P = (m_cInverseTransform.getValue() * lineStart).eval();
auto const D = (m_cInverseTransform.getValue().linear() * lineDir).eval();
T a = D[1] * D[1] + D[2] * D[2];
T b = static_cast<T>(2) * (P[1] * D[1] + P[2] * D[2]);
T c = (P[1] * P[1] + P[2] * P[2] - m_cr * m_cr);
T discriminant = b * b - static_cast<T>(4) * a * c;
if (discriminant < 0.0)
{
// Cannot use a sqrt on a negative number. Push it to zero if it is small.
if (discriminant >= -Geometry::ScalarEpsilon)
{
discriminant = 0.0;
}
else
{
return std::numeric_limits<T>::quiet_NaN();
}
}
// We have two solutions. We want the larger value.
double d = (-b / (static_cast<T>(2) * a)) + std::abs(std::sqrt(discriminant) / (static_cast<T>(2) * a));
SURGSIM_ASSERT(isValid(d));
if (point != nullptr)
{
*point = lineStart + lineDir * d;
}
return d;
}
/// \param lineStart The start of the line segment
/// \param lineDir The direction of the line segment
/// \param point [in,out] The point which is to be clipped.
/// \param pointOnCapsuleAxis [out] The recalculated point on the capsule axis.
/// \return The distance of the point of intersection from the lineStart.
/// \note Asserts when there is no intersection.
double farthestIntersectionLineCapsule(const Vector3& lineStart, const Vector& lineDir,
Vector3* point, Vector3* pointOnCapsuleAxis)
{
// Transform the problem into the capsule space to solve the local capsule equation. The capsule coordinate
// system has its origin on one the capsule ends (m_cvTop), the x axis is along the capsule axis (m_cAxis), and
// the y and z axes are any orthogonal vectors to the capsule axis. The equation of the capsule can be written
// as the following:
// x^2 + y^2 + z^2 = r^2 | x < 0 ------ [1]
// y^2 + z^2 = r^2 | 0 < x < length ------ [2]
// (x - length)^2 + y^2 + z^2 = r^2 | x > length ------ [3]
// Point should be on the line, P + t.(D)
// First find the intersection with an infinite cylinder centered around the capsule axis.
double d = farthestIntersectionLineCylinder(lineStart, lineDir, point);
SURGSIM_ASSERT(isValid(d));
*point = lineStart + lineDir * d;
// When x <0 or x > length, the equation of the capsule is that of the sphere (from equations [1] and [3]). So,
// the intersection between the line (P + t.D) and the sphere is calculated as below. Here l is the length of
// the capsule.
// => ((P + t.D).x - l)^2 + (P + t.D).y^2 + (P + t.D).z^2 = r^2
// => Px^2 + t^2.Dx^2 + l^2 + 2.Px.t.Dx - 2.t.Dx.l - 2.Px.l +
// Py^2 + t^2.Dy^2 + 2.Py.t.Dy + Pz^2 + t^2.Dz^2 + 2.Pz.t.Dz = r^2
// => t^2.(Dx^2 + Dy^2 + Dz^2) + t.(2.Px.Dx + 2.Py.Dy + 2.Pz.Dz - 2.Dx.l) +
// (Px^2 + Py^2 + Pz^2 + l^2 - 2.Px.l - r^2) = 0
// Let a = (Dx^2 + Dy^2 + Dz^2),
// b = (2.Px.Dx + 2.Py.Dy + 2.Pz.Dz - 2.Dx.l),
// c = (Px^2 + Py^2 + Pz^2 + l^2 - 2.Px.l - r^2):
double x = ((*point) - m_cvTop).dot(m_cAxis);
if (x <= 0.0 || x >= m_cLength)
{
x = (x <= 0.0) ? 0.0 : m_cLength;
auto const P = (m_cInverseTransform.getValue() * lineStart).eval();
auto const D = (m_cInverseTransform.getValue().linear() * lineDir).eval();
T a = D[0] * D[0] + D[1] * D[1] + D[2] * D[2];
T b = static_cast<T>(2) * (P[0] * D[0] + P[1] * D[1] + P[2] * D[2] - D[0] * x);
T c = (P[0] * P[0] + P[1] * P[1] + P[2] * P[2] + x * x - static_cast<T>(2) * P[0] * x - m_cr * m_cr);
// => t^2.a + t.b + c = 0, whose solution is:
// (-b +/- sqrt(b^2 - 4*a*c))/2*a
T discriminant = b * b - static_cast<T>(4) * a * c;
if (discriminant < 0.0 && discriminant >= -Geometry::ScalarEpsilon)
{
discriminant = 0.0;
}
// We have two solutions. We want the smaller value.
d = (-b - std::abs(std::sqrt(discriminant))) / (static_cast<T>(2) * a);
SURGSIM_ASSERT(isValid(d));
*point = lineStart + lineDir * d;
}
*pointOnCapsuleAxis = m_cTransform * Vector3(x, 0.0, 0.0);
return d;
}
/// \param segmentStart [in,out] The start of the line segment
/// \param segmentEnd [in,out] The end of the line segment
/// \param v The vertices of the triangle.
/// \param planeN Normals of the triangle and each of the edge planes.
/// \param planeD d from plane equation for the plane of the triangle and each of the edge planes.
/// \return The index of the last plane which clips the segment passed in.
size_t clipSegmentAgainstTriangle(Vector3* segmentStart, Vector3* segmentEnd, Vector3* v, Vector3* planeN,
double* planeD)
{
double ratio, dStart, dEnd;
size_t j = 4;
for (size_t i = 0; i < 4; ++i)
{
dStart = segmentStart->dot(planeN[i]) + planeD[i];
dEnd = segmentEnd->dot(planeN[i]) + planeD[i];
if (dStart < -m_epsilon && dEnd > m_epsilon)
{
ratio = std::abs(dStart) / (std::abs(dStart) + dEnd);
*segmentEnd = *segmentStart + (*segmentEnd - *segmentStart) * ratio;
j = i;
}
else if (dStart > m_epsilon && dEnd < -m_epsilon)
{
ratio = dStart / (dStart + std::abs(dEnd));
*segmentStart = *segmentStart + (*segmentEnd - *segmentStart) * ratio;
j = i;
}
else if (dStart < m_epsilon && dEnd > m_epsilon)
{
*segmentEnd = *segmentStart;
j = i;
}
else if (dStart > m_epsilon && dEnd < m_epsilon)
{
*segmentStart = *segmentEnd;
j = i;
}
}
SURGSIM_ASSERT(j < 4) << "The clipping should have happened at least with the triangle plane.";
return j;
}
///@{
/// Triangle vertices and normal.
Vector3 m_tv0;
Vector3 m_tv1;
Vector3 m_tv2;
Vector3 m_tn;
///@}
///@{
/// Capsule ends, axis , radius and length.
Vector3 m_cvTop;
Vector3 m_cvBottom;
Vector3 m_cAxis;
double m_cr;
double m_cLength;
///@}
/// Distance between triangle and capsule
double m_distance;
///@{
/// Contact info
T m_penetrationDepth;
Vector3 m_penetrationPointTriangle;
Vector3 m_penetrationPointCapsule;
Vector3 m_contactNormal;
Vector3 m_penetrationPointCapsuleAxis;
///@}
/// The transform of the capsule
RigidTransform3 m_cTransform;
/// The inverse transform of the capsule
SurgSim::DataStructures::OptionalValue<RigidTransform3> m_cInverseTransform;
/// epsilon
T m_epsilon;
};
}
template <class T, int MOpt> inline
bool calculateContactTriangleCapsule(
const Eigen::Matrix<T, 3, 1, MOpt>& tv0,
const Eigen::Matrix<T, 3, 1, MOpt>& tv1,
const Eigen::Matrix<T, 3, 1, MOpt>& tv2,
const Eigen::Matrix<T, 3, 1, MOpt>& tn,
const Eigen::Matrix<T, 3, 1, MOpt>& cv0,
const Eigen::Matrix<T, 3, 1, MOpt>& cv1,
double cr,
T* penetrationDepth,
Eigen::Matrix<T, 3, 1, MOpt>* penetrationPointTriangle,
Eigen::Matrix<T, 3, 1, MOpt>* penetrationPointCapsule,
Eigen::Matrix<T, 3, 1, MOpt>* contactNormal,
Eigen::Matrix<T, 3, 1, MOpt>* penetrationPointCapsuleAxis)
{
TriangleCapsuleContactCalculation::TriangleCapsuleContactCalculation<T, MOpt>
calc(tv0, tv1, tv2, tn, cv0, cv1, cr);
if (calc.isIntersecting())
{
calc.calculateContact(penetrationDepth, penetrationPointTriangle, penetrationPointCapsule,
contactNormal, penetrationPointCapsuleAxis);
return true;
}
return false;
}
template <class T, int MOpt> inline
bool calculateContactTriangleCapsule(
const Eigen::Matrix<T, 3, 1, MOpt>& tv0,
const Eigen::Matrix<T, 3, 1, MOpt>& tv1,
const Eigen::Matrix<T, 3, 1, MOpt>& tv2,
const Eigen::Matrix<T, 3, 1, MOpt>& cv0,
const Eigen::Matrix<T, 3, 1, MOpt>& cv1,
double cr,
T* penetrationDepth,
Eigen::Matrix<T, 3, 1, MOpt>* penetrationPoint0,
Eigen::Matrix<T, 3, 1, MOpt>* penetrationPoint1,
Eigen::Matrix<T, 3, 1, MOpt>* contactNormal,
Eigen::Matrix<T, 3, 1, MOpt>* penetrationPointCapsuleAxis)
{
Eigen::Matrix<T, 3, 1, MOpt> tn = (tv1 - tv0).cross(tv2 - tv0);
Eigen::Matrix<T, 3, 1, MOpt> ca = cv1 - cv0;
if (tn.isZero() || ca.isZero())
{
// Degenerate triangle/capsule passed to calculateContactTriangleTriangle
return false;
}
tn.normalize();
return calculateContactTriangleCapsule(tv0, tv1, tv2, tn, cv0, cv1, cr, penetrationDepth,
penetrationPoint0, penetrationPoint1, contactNormal, penetrationPointCapsuleAxis);
}
} // namespace Math
} // namespace SurgSim
#endif // SURGSIM_MATH_TRIANGLECAPSULECONTACTCALCULATION_INL_H
|