From 9f559af2a8d25d275601471a6c4d9b1e6ca9d231 Mon Sep 17 00:00:00 2001
From: Xuchen Han <xuchenhan2015@u.northwestern.edu>
Date: Mon, 19 Aug 2019 13:07:26 -0700
Subject: [PATCH] set m_contact_iterations to solverInfo.m_solverIterations

---
 src/BulletSoftBody/btDeformableBodySolver.cpp        | 5 ++++-
 src/BulletSoftBody/btDeformableContactProjection.cpp | 1 +
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/BulletSoftBody/btDeformableBodySolver.cpp b/src/BulletSoftBody/btDeformableBodySolver.cpp
index b173aa53b..85730cc1e 100644
--- a/src/BulletSoftBody/btDeformableBodySolver.cpp
+++ b/src/BulletSoftBody/btDeformableBodySolver.cpp
@@ -21,7 +21,6 @@
 btDeformableBodySolver::btDeformableBodySolver()
 : m_numNodes(0)
 , m_cg(50)
-, m_contact_iterations(5)
 {
     m_objective = new btDeformableBackwardEulerObjective(m_softBodySet, m_backupVelocity);
 }
@@ -79,12 +78,16 @@ void btDeformableBodySolver::setConstraints()
 {
     BT_PROFILE("setConstraint");
     m_objective->setConstraints();
+    // m_contact_iterations takes over m_numIterations
+    m_contact_iterations = m_objective->m_world->getSolverInfo().m_numIterations;
     for (int i = 0; i < m_contact_iterations; ++i)
     {
         m_objective->projection.update();
         m_objective->enforceConstraint(m_dv);
         m_objective->updateVelocity(m_dv);
     }
+    // recover m_numIterations from m_contact_iterations
+    m_objective->m_world->getSolverInfo().m_numIterations = m_contact_iterations;
 }
 
 void btDeformableBodySolver::setWorld(btDeformableMultiBodyDynamicsWorld* world)
diff --git a/src/BulletSoftBody/btDeformableContactProjection.cpp b/src/BulletSoftBody/btDeformableContactProjection.cpp
index e03001c3f..ba8f74144 100644
--- a/src/BulletSoftBody/btDeformableContactProjection.cpp
+++ b/src/BulletSoftBody/btDeformableContactProjection.cpp
@@ -21,6 +21,7 @@ void btDeformableContactProjection::update()
 {
     ///solve rigid body constraints
     {
+        // m_numIterations get temporarily to 1 so that we interleave one step of multibody solve with one step of multibody/deformable contact solve
         m_world->getSolverInfo().m_numIterations = 1;
         m_world->processIslands();
         m_world->btMultiBodyDynamicsWorld::solveInternalConstraints(m_world->getSolverInfo()); // process constraints deferred in the previous step