C++ (Cpp) Vector3f::cwiseMax Examples

Example #1

File: Shapes.cpp Project: danielkeller/Violet

AlignedBox3f Bound(const Mesh& m)
{
	float maxflt = std::numeric_limits<float>::max();
	Eigen::Vector3f min{ maxflt, maxflt, maxflt };
	Eigen::Vector3f max = -min;

	for (const auto& tri : m)
	{
		min = min.cwiseMin(tri.rowwise().minCoeff());
		max = max.cwiseMax(tri.rowwise().maxCoeff());
	}

	return{ min, max };
}

Example #2

File: Shapes.cpp Project: danielkeller/Violet

OBB::OBB(Mesh::const_iterator begin, Mesh::const_iterator end)
{
	if (begin == end)
	{
		axes = -ZERO_SIZE * Matrix3f::Identity(); //make it inside out (i guess)
		origin = Vector3f::Zero();
		return;
	}

	Vector3f centerOfMass = centroid(begin, end);
	Matrix3f inertiaTensor = Matrix3f::Zero();

	auto addPt = [&](const Vector3f& pt, float mass)
	{
		Vector3f lpos = pt - centerOfMass;

		inertiaTensor(0, 0) += (lpos.y()*lpos.y() + lpos.z()*lpos.z()) * mass;
		inertiaTensor(1, 1) += (lpos.x()*lpos.x() + lpos.z()*lpos.z()) * mass;
		inertiaTensor(2, 2) += (lpos.x()*lpos.x() + lpos.y()*lpos.y()) * mass;
		inertiaTensor(1, 0) -= lpos.x()*lpos.y() * mass;
		inertiaTensor(2, 0) -= lpos.x()*lpos.z() * mass;
		inertiaTensor(2, 1) -= lpos.y()*lpos.z() * mass;
	};

	for (const auto& tri : make_range(begin, end))
	{
		float area = TriNormal(tri).norm() / 6.f;
		addPt(tri.col(0), area);
		addPt(tri.col(1), area);
		addPt(tri.col(2), area);
	}

	Eigen::SelfAdjointEigenSolver<Matrix3f> es;
	es.computeDirect(inertiaTensor);
	axes = es.eigenvectors();

	float maxflt = std::numeric_limits<float>::max();
	Eigen::Vector3f min{ maxflt, maxflt, maxflt };
	Eigen::Vector3f max = -min;

	for (const auto& tri : make_range(begin, end))
	{
		min = min.cwiseMin((axes.transpose() * tri).rowwise().minCoeff());
		max = max.cwiseMax((axes.transpose() * tri).rowwise().maxCoeff());
	}

    extent = (max - min).cwiseMax(ZERO_SIZE) / 2.f;
    origin = axes * (min + extent);
}