MeshToolsLib::ProjectPointOnMesh Namespace Reference

Functions
MeshLib::Element const *	getProjectedElement (std::vector< const MeshLib::Element * > const &elements, MathLib::Point3d const &node)
double	getElevation (MeshLib::Element const &element, MathLib::Point3d const &node)

Function Documentation

getElevation()

double MeshToolsLib::ProjectPointOnMesh::getElevation	(	MeshLib::Element const &	element,
		MathLib::Point3d const &	node )

Returns the z-coordinate of a point projected onto the plane defined by a mesh element.

Definition at line 57 of file ProjectPointOnMesh.cpp.

{
    // mathematical description of the plane spanned by the 2d element
    // compute coefficients of the plane equation (Hesse normal form)
    // d = scalar_product(normal, element_node[0])
    auto const n = MeshLib::FaceRule::getSurfaceNormal(element).normalized();
    auto const d = n.dot(element.getNode(0)->asEigenVector3d());
    // insert node[0] and node[1] into plane equation and transpose the equation
    // to node[2]
    return (d - (node[0] * n[0] + node[1] * n[1])) / n[2];
}

References MathLib::Point3d::asEigenVector3d(), MeshLib::Element::getNode(), and MeshLib::FaceRule::getSurfaceNormal().

Referenced by main(), and voteMatId().

getProjectedElement()

MeshLib::Element const * MeshToolsLib::ProjectPointOnMesh::getProjectedElement	(	std::vector< const MeshLib::Element * > const &	elements,
		MathLib::Point3d const &	node )

Returns the element in which the given node is located when projected onto a mesh, or nullptr if no such element was found.

Definition at line 21 of file ProjectPointOnMesh.cpp.

{
    auto is_right_of = [&node](MeshLib::Node const& a, MeshLib::Node const& b)
    { return GeoLib::getOrientation(node, a, b) == GeoLib::Orientation::CW; };
 
    for (auto const* e : elements)
    {
        auto const* nodes = e->getNodes();
        if (e->getGeomType() == MeshLib::MeshElemType::TRIANGLE)
        {
            auto const& a = *nodes[0];
            auto const& b = *nodes[1];
            auto const& c = *nodes[2];
            if (!is_right_of(a, b) && !is_right_of(b, c) && !is_right_of(c, a))
            {
                return e;
            }
        }
        else if (e->getGeomType() == MeshLib::MeshElemType::QUAD)
        {
            auto const& a = *nodes[0];
            auto const& b = *nodes[1];
            auto const& c = *nodes[2];
            auto const& d = *nodes[3];
            if (!is_right_of(a, b) && !is_right_of(b, c) &&
                !is_right_of(c, d) && !is_right_of(d, a))
            {
                return e;
            }
        }
    }
    return nullptr;
}

References GeoLib::CW, GeoLib::getOrientation(), MeshLib::QUAD, and MeshLib::TRIANGLE.

Referenced by getProjectedElement(), and main().