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remove preconditioning experiments; use preconditioning by default; write delta

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This commit is contained in:
Irlan 2018-05-17 16:17:58 -03:00
parent 2fa4532b01
commit 3be2152264
1 changed files with 35 additions and 70 deletions
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105
src/bounce/dynamics/cloth/spring_solver.cpp
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@ -26,9 +26,6 @@
// Here, we solve Ax = b using the Modified Conjugate Gradient method.
// This work is based on the paper "Large Steps in Cloth Simulation - David Baraff, Andrew Witkin".
// Enable preconditioning.
bool b3_enablePrecontitioning = false;
b3SpringSolver::b3SpringSolver(const b3SpringSolverDef& def)
{
m_cloth = def.cloth;
@ -100,7 +97,8 @@ void b3SpringSolver::Solve(b3DenseVec3& f)
// S
b3Mat33* S = (b3Mat33*)m_allocator->Allocate(m_massCount * sizeof(b3Mat33));
Compute_S(S);
// Solve Ax = b
Solve(x, f, m_iterations, A, b, S);
// Update state
@ -391,14 +389,14 @@ void b3SpringSolver::Compute_S(b3Mat33* out)
if (m_contacts[i].lockT1 == true)
{
b3Vec3 t1 = m_contacts[i].t1;
S -= b3Outer(t1, t1);
}
if (m_contacts[i].lockT2 == true)
{
b3Vec3 t2 = m_contacts[i].t2;
S -= b3Outer(t2, t2);
}
}
@ -429,25 +427,6 @@ static void b3Filter(b3DenseVec3& out,
}
}
// Sylvester's Criterion
static bool b3IsPD(const b3Mat33* diagA, u32 n)
{
// Loop over the principal elements
for (u32 i = 0; i < n; ++i)
{
b3Mat33 a = diagA[i];
float32 D = b3Det(a.x, a.y, a.z);
if (D <= B3_EPSILON)
{
return false;
}
}
return true;
}
void b3SpringSolver::Solve(b3DenseVec3& dv, b3DenseVec3& e, u32& iterations, const b3SparseMat33& A, const b3DenseVec3& b, const b3Mat33* S) const
{
b3DenseVec3 P(m_massCount);
@ -455,58 +434,44 @@ void b3SpringSolver::Solve(b3DenseVec3& dv, b3DenseVec3& e, u32& iterations, con
b3DenseVec3 inv_P(m_massCount);
// Compute P, P^-1
if (b3_enablePrecontitioning)
{
// P = diag(A)^-1
// diag(A)
b3Mat33* diagA = (b3Mat33*)m_allocator->Allocate(m_massCount * sizeof(b3Mat33));
A.AssembleDiagonal(diagA);
for (u32 i = 0; i < m_massCount; ++i)
{
b3Mat33 D = diagA[i];
// P = diag(A)^-1
// Sylvester's Criterion
B3_ASSERT(b3Det(D.x, D.y, D.z) <= B3_EPSILON);
// diag(A)
b3Mat33* diagA = (b3Mat33*)m_allocator->Allocate(m_massCount * sizeof(b3Mat33));
A.AssembleDiagonal(diagA);
B3_ASSERT(D[0][0] != 0.0f);
B3_ASSERT(D[1][1] != 0.0f);
B3_ASSERT(D[2][2] != 0.0f);
P[i] = b3Vec3(1.0f / D[0][0], 1.0f / D[1][1], 1.0f / D[2][2]);
inv_P[i] = b3Vec3(D[0][0], D[1][1], D[2][2]);
}
m_allocator->Free(diagA);
}
else
{
// P = I
for (u32 i = 0; i < m_massCount; ++i)
{
P[i].Set(1.0f, 1.0f, 1.0f);
}
for (u32 i = 0; i < m_massCount; ++i)
{
inv_P[i].Set(1.0f, 1.0f, 1.0f);
}
}
// eps0 = dot( filter(b), P * filter(b) )
b3DenseVec3 filtered_b(m_massCount);
b3Filter(filtered_b, b, S, m_massCount);
b3DenseVec3 P_filtered_b(m_massCount);
for (u32 i = 0; i < m_massCount; ++i)
{
P_filtered_b[i][0] = P[i][0] * filtered_b[i][0];
P_filtered_b[i][1] = P[i][1] * filtered_b[i][1];
P_filtered_b[i][2] = P[i][2] * filtered_b[i][2];
b3Mat33 D = diagA[i];
// Sylvester Criterion to ensure PD-ness
B3_ASSERT(b3Det(D.x, D.y, D.z) > B3_EPSILON);
B3_ASSERT(D[0][0] != 0.0f);
B3_ASSERT(D[1][1] != 0.0f);
B3_ASSERT(D[2][2] != 0.0f);
P[i] = b3Vec3(1.0f / D[0][0], 1.0f / D[1][1], 1.0f / D[2][2]);
inv_P[i] = b3Vec3(D[0][0], D[1][1], D[2][2]);
}
float32 delta0 = b3Dot(filtered_b, P_filtered_b);
m_allocator->Free(diagA);
// delta0 = dot(filter(b), P * filter(b))
b3DenseVec3 S_b(m_massCount);
b3Filter(S_b, b, S, m_massCount);
// P * S * b
b3DenseVec3 P_S_b(m_massCount);
for (u32 i = 0; i < m_massCount; ++i)
{
P_S_b[i][0] = P[i][0] * S_b[i][0];
P_S_b[i][1] = P[i][1] * S_b[i][1];
P_S_b[i][2] = P[i][2] * S_b[i][2];
}
float32 delta0 = b3Dot(S_b, P_S_b);
// r = filter(b - Adv)
b3DenseVec3 r = b - A * dv;