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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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65
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. // 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". // 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) b3SpringSolver::b3SpringSolver(const b3SpringSolverDef& def)
{ {
m_cloth = def.cloth; m_cloth = def.cloth;
@ -101,6 +98,7 @@ void b3SpringSolver::Solve(b3DenseVec3& f)
b3Mat33* S = (b3Mat33*)m_allocator->Allocate(m_massCount * sizeof(b3Mat33)); b3Mat33* S = (b3Mat33*)m_allocator->Allocate(m_massCount * sizeof(b3Mat33));
Compute_S(S); Compute_S(S);
// Solve Ax = b
Solve(x, f, m_iterations, A, b, S); Solve(x, f, m_iterations, A, b, S);
// Update state // Update state
@ -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 void b3SpringSolver::Solve(b3DenseVec3& dv, b3DenseVec3& e, u32& iterations, const b3SparseMat33& A, const b3DenseVec3& b, const b3Mat33* S) const
{ {
b3DenseVec3 P(m_massCount); b3DenseVec3 P(m_massCount);
@ -455,8 +434,7 @@ void b3SpringSolver::Solve(b3DenseVec3& dv, b3DenseVec3& e, u32& iterations, con
b3DenseVec3 inv_P(m_massCount); b3DenseVec3 inv_P(m_massCount);
// Compute P, P^-1 // Compute P, P^-1
if (b3_enablePrecontitioning)
{
// P = diag(A)^-1 // P = diag(A)^-1
// diag(A) // diag(A)
@ -467,8 +445,8 @@ void b3SpringSolver::Solve(b3DenseVec3& dv, b3DenseVec3& e, u32& iterations, con
{ {
b3Mat33 D = diagA[i]; b3Mat33 D = diagA[i];
// Sylvester's Criterion // Sylvester Criterion to ensure PD-ness
B3_ASSERT(b3Det(D.x, D.y, D.z) <= B3_EPSILON); B3_ASSERT(b3Det(D.x, D.y, D.z) > B3_EPSILON);
B3_ASSERT(D[0][0] != 0.0f); B3_ASSERT(D[0][0] != 0.0f);
B3_ASSERT(D[1][1] != 0.0f); B3_ASSERT(D[1][1] != 0.0f);
@ -479,34 +457,21 @@ void b3SpringSolver::Solve(b3DenseVec3& dv, b3DenseVec3& e, u32& iterations, con
} }
m_allocator->Free(diagA); m_allocator->Free(diagA);
}
else // delta0 = dot(filter(b), P * filter(b))
{ b3DenseVec3 S_b(m_massCount);
// P = I b3Filter(S_b, b, S, m_massCount);
// P * S * b
b3DenseVec3 P_S_b(m_massCount);
for (u32 i = 0; i < m_massCount; ++i) for (u32 i = 0; i < m_massCount; ++i)
{ {
P[i].Set(1.0f, 1.0f, 1.0f); 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];
} }
for (u32 i = 0; i < m_massCount; ++i) float32 delta0 = b3Dot(S_b, P_S_b);
{
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];
}
float32 delta0 = b3Dot(filtered_b, P_filtered_b);
// r = filter(b - Adv) // r = filter(b - Adv)
b3DenseVec3 r = b - A * dv; b3DenseVec3 r = b - A * dv;