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Reverts to Taylor Series approximation of Clothoid curve.

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If you compare the results generated by the numeric integration and the approximation, they are very different. The approximation compares will with other software so there is likely a problem with the equation of the clothoid
This commit is contained in:
Richard Brice
2023-09-29 11:49:43 -07:00
parent f9d259a3d8
commit 00d8ffeba0
1 changed files with 80 additions and 80 deletions
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src/ifcgeom/mapping/IfcCurveSegment.cpp
+80 -80
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@@ -98,64 +98,64 @@ public:
}
// Clothoid using Taylor Series approximation
//#ifdef SCHEMA_HAS_IfcClothoid
// // Then initialize Function(double) -> Vector3, by means of IfcCurve subtypes
// void operator()(IfcSchema::IfcClothoid* c) {
// // @todo verify
// auto sign = [](double v)->int{return v < 0 ? -1 : (0 < v ? 1 : 0); };
// auto sign_s = sign(start_);
// auto sign_l = sign(length_);
// double L = 0;
// if (sign_s == 0) L = fabs(length_);
// else if (sign_s == sign_l) L = fabs(start_ + length_);
// else L = fabs(start_);
//
// auto A = c->ClothoidConstant();
// auto R = A * A / L;
// auto RL = (A < 0 ? -1.0 : 1.0) * R * L;
//
// auto position = c->Position();
// auto placement = position->as<IfcSchema::IfcAxis2Placement2D>();
// auto ref_direction = placement->RefDirection();
// double theta = 0.0; // angle the circle's placement X-axis makes with respect to global X axis
// if (ref_direction)
// {
// auto dr = ref_direction->DirectionRatios();
// auto dx = dr[0];
// auto dy = dr[1];
// theta = atan2(dy, dx);
// }
//
// auto C = placement->Location();
// if (!C->as<IfcSchema::IfcCartesianPoint>())
// {
// throw std::runtime_error("Only IfcCartesianPoint is supported for center of IfcCircle");
// // @todo add support for other IfcPoint subtypes
// }
// auto Cx = C->as<IfcSchema::IfcCartesianPoint>()->Coordinates()[0];
// auto Cy = C->as<IfcSchema::IfcCartesianPoint>()->Coordinates()[1];
//
// eval_ = [RL,Cx,Cy,theta](double u) {
// // coordinate along clothoid is local coordinates
// auto xterm_1 = u;
// auto xterm_2 = std::pow(u, 5) / (40 * std::pow(RL, 2));
// auto xterm_3 = std::pow(u, 9) / (3456 * std::pow(RL, 4));
// auto xterm_4 = std::pow(u, 13) / (599040 * std::pow(RL, 6));
// auto xl = xterm_1 - xterm_2 + xterm_3 - xterm_4;
//
// auto yterm_1 = std::pow(u, 3) / (6 * RL);
// auto yterm_2 = std::pow(u, 7) / (336 * std::pow(RL, 3));
// auto yterm_3 = std::pow(u, 11) / (42240 * std::pow(RL, 5));
// auto yterm_4 = std::pow(u, 15) / (9676800 * std::pow(RL, 7));
// auto yl = yterm_1 - yterm_2 + yterm_3 - yterm_4;
//
// // transform point into clothoid's coodinate system
// auto x = xl * cos(theta) - yl * sin(theta) + Cx;
// auto y = xl * sin(theta) + yl * cos(theta) + Cy;
// return Eigen::Vector3d(x, y, 0.0);
// };
// }
//#endif
#ifdef SCHEMA_HAS_IfcClothoid
// Then initialize Function(double) -> Vector3, by means of IfcCurve subtypes
void operator()(IfcSchema::IfcClothoid* c) {
// @todo verify
auto sign = [](double v)->int{return v < 0 ? -1 : (0 < v ? 1 : 0); };
auto sign_s = sign(start_);
auto sign_l = sign(length_);
double L = 0;
if (sign_s == 0) L = fabs(length_);
else if (sign_s == sign_l) L = fabs(start_ + length_);
else L = fabs(start_);
auto A = c->ClothoidConstant();
auto R = A * A / L;
auto RL = (A < 0 ? -1.0 : 1.0) * R * L;
auto position = c->Position();
auto placement = position->as<IfcSchema::IfcAxis2Placement2D>();
auto ref_direction = placement->RefDirection();
double theta = 0.0; // angle the circle's placement X-axis makes with respect to global X axis
if (ref_direction)
{
auto dr = ref_direction->DirectionRatios();
auto dx = dr[0];
auto dy = dr[1];
theta = atan2(dy, dx);
}
auto C = placement->Location();
if (!C->as<IfcSchema::IfcCartesianPoint>())
{
throw std::runtime_error("Only IfcCartesianPoint is supported for center of IfcCircle");
// @todo add support for other IfcPoint subtypes
}
auto Cx = C->as<IfcSchema::IfcCartesianPoint>()->Coordinates()[0];
auto Cy = C->as<IfcSchema::IfcCartesianPoint>()->Coordinates()[1];
eval_ = [RL,Cx,Cy,theta](double u) {
// coordinate along clothoid is local coordinates
auto xterm_1 = u;
auto xterm_2 = std::pow(u, 5) / (40 * std::pow(RL, 2));
auto xterm_3 = std::pow(u, 9) / (3456 * std::pow(RL, 4));
auto xterm_4 = std::pow(u, 13) / (599040 * std::pow(RL, 6));
auto xl = xterm_1 - xterm_2 + xterm_3 - xterm_4;
auto yterm_1 = std::pow(u, 3) / (6 * RL);
auto yterm_2 = std::pow(u, 7) / (336 * std::pow(RL, 3));
auto yterm_3 = std::pow(u, 11) / (42240 * std::pow(RL, 5));
auto yterm_4 = std::pow(u, 15) / (9676800 * std::pow(RL, 7));
auto yl = yterm_1 - yterm_2 + yterm_3 - yterm_4;
// transform point into clothoid's coodinate system
auto x = xl * cos(theta) - yl * sin(theta) + Cx;
auto y = xl * sin(theta) + yl * cos(theta) + Cy;
return Eigen::Vector3d(x, y, 0.0);
};
}
#endif
void set_spiral_functor(mapping* mapping,IfcSchema::IfcSpiral* s, std::function<double(double)> signX,std::function<double(double)> fnX, std::function<double(double)> signY, std::function<double(double)> fnY)
{
@@ -189,28 +189,28 @@ public:
}
// Clothoid using numerical integration
#ifdef SCHEMA_HAS_IfcClothoid
// Then initialize Function(double) -> Vector3, by means of IfcCurve subtypes
void operator()(IfcSchema::IfcClothoid* c) {
auto A = c->ClothoidConstant();
// the integration is for the +X, +Y quadrant - need to adjust the signs of the resulting X and Y values
// so that the results are in the correct quadrant.
// A > 0 and u > 0 -> +X, +Y
// A < 0 and u > 0 -> +X, -Y
// A > 0 and u < 0 -> -X, -Y
// A < 0 and u < 0 -> -X, +Y
// X depends only on u, Y depends on u and A.
auto sign = [](double v)->int {return v < 0 ? -1 : 1; }; // returns -1 or 1
auto sign_x = [sign](double t) {return sign(t); };
auto sign_y = [sign, A](double t) {return sign(t) == sign(A) ? 1.0 : -1.0; };
auto fn_x = [A](double t)->double {return A * sqrt(PI) * cos(PI * A * t * t / (2 * fabs(A))); };
auto fn_y = [A](double t)->double {return A * sqrt(PI) * sin(PI * A * t * t / (2 * fabs(A))); };
set_spiral_functor(mapping_,c->as<IfcSchema::IfcSpiral>(), sign_x, fn_x, sign_y, fn_y);
}
#endif
//#ifdef SCHEMA_HAS_IfcClothoid
//// Then initialize Function(double) -> Vector3, by means of IfcCurve subtypes
// void operator()(IfcSchema::IfcClothoid* c) {
//
// auto A = c->ClothoidConstant();
//
// // the integration is for the +X, +Y quadrant - need to adjust the signs of the resulting X and Y values
// // so that the results are in the correct quadrant.
// // A > 0 and u > 0 -> +X, +Y
// // A < 0 and u > 0 -> +X, -Y
// // A > 0 and u < 0 -> -X, -Y
// // A < 0 and u < 0 -> -X, +Y
// // X depends only on u, Y depends on u and A.
// auto sign = [](double v)->int {return v < 0 ? -1 : 1; }; // returns -1 or 1
// auto sign_x = [sign](double t) {return sign(t); };
// auto sign_y = [sign, A](double t) {return sign(t) == sign(A) ? 1.0 : -1.0; };
// auto fn_x = [A](double t)->double {return A * sqrt(PI) * cos(PI * A * t * t / (2 * fabs(A))); };
// auto fn_y = [A](double t)->double {return A * sqrt(PI) * sin(PI * A * t * t / (2 * fabs(A))); };
//
// set_spiral_functor(mapping_,c->as<IfcSchema::IfcSpiral>(), sign_x, fn_x, sign_y, fn_y);
// }
//#endif
#ifdef SCHEMA_HAS_IfcSecondOrderPolynomialSpiral
void operator()(IfcSchema::IfcSecondOrderPolynomialSpiral* s)