Esempio n. 1
0
void AttachmentConstraint::PBDProject(VectorX& x, const SparseMatrix& inv_mass, unsigned int ns)
{
	// LOOK
	ScalarType k_prime = 1 - std::pow(1-*(m_p_pbd_stiffness), 1.0/ns);
	
	EigenVector3 p = x.block_vector(m_p0);
	EigenVector3 dp = m_fixd_point-p;

	x.block_vector(m_p0) += k_prime * dp;
}
Esempio n. 2
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// sping gradient: k*(current_length-rest_length)*current_direction;
void SpringConstraint::EvaluateGradient(const VectorX& x, VectorX& gradient)
{
	// TODO
	//EigenVector3 g_i = (*(m_p_stiffness))*(x.block_vector(m_p0) - m_fixd_point);
    //gradient.block_vector(m_p0) += g_i;

	EigenVector3 p1=x.block_vector(m_p1);
	EigenVector3 p2=x.block_vector(m_p2);
	float currentLength=(p1-p2).norm();
	float force=(*this->m_p_stiffness)*(currentLength-this->m_rest_length);
	EigenVector3 n1=p1-p2,n2=p2-p1;
	n1.normalize();n2.normalize();
	gradient.block_vector(m_p1)+=n1*force;
	gradient.block_vector(m_p2)+=n2*force;
}
Esempio n. 3
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void SpringConstraint::PBDProject(VectorX& x, const SparseMatrix& inv_mass, unsigned int ns)
{
	// TODO
	// change project order
	ScalarType k_prime = 1 - std::pow(1-*(m_p_pbd_stiffness), 1.0/ns);

	float rest_length=m_rest_length;
	EigenVector3 p1 = x.block_vector(m_p1);
	EigenVector3 p2 = x.block_vector(m_p2);

	float current_length=(p1-p2).norm();
	EigenVector3 current_direction=(p1-p2)/current_length;
	EigenVector3 dp=(current_length-rest_length)*current_direction;

	ScalarType w1=inv_mass.coeff(m_p1,m_p1);
	ScalarType w2=inv_mass.coeff(m_p2,m_p2);

	x.block_vector(m_p1) -= k_prime * dp*w1/(w1+w2);
	x.block_vector(m_p2) += k_prime * dp*w2/(w1+w2);
}
Esempio n. 4
0
// attachment spring gradient: k*(current_length)*current_direction
void AttachmentConstraint::EvaluateGradient(const VectorX& x, VectorX& gradient)
{
	// LOOK
    EigenVector3 g_i = (*(m_p_stiffness))*(x.block_vector(m_p0) - m_fixd_point);
    gradient.block_vector(m_p0) += g_i;
}