From fa00ee2bbd82f063733f1c0f8c3029e02fca2cc4 Mon Sep 17 00:00:00 2001
From: jingyuc <chenjy@g.ucla.edu>
Date: Tue, 13 Jul 2021 00:45:11 -0400
Subject: [PATCH] Start the reduced deformable example. Read in mesh and modes
 files.

---
 examples/ExampleBrowser/CMakeLists.txt       |   2 +
 examples/ExampleBrowser/ExampleEntries.cpp   |   5 +
 examples/ReducedDeformableDemo/BasicTest.cpp | 286 +++++++++++++++++++
 examples/ReducedDeformableDemo/BasicTest.h   |  19 ++
 examples/SoftDemo/K_r_diag_mat.bin           | Bin 0 -> 100 bytes
 examples/SoftDemo/M_r_diag_mat.bin           | Bin 0 -> 100 bytes
 examples/SoftDemo/eigenvalues.bin            | Bin 0 -> 100 bytes
 examples/SoftDemo/mesh.vtk                   |  83 ++++++
 examples/SoftDemo/modes.bin                  | Bin 0 -> 8068 bytes
 src/BulletSoftBody/btSoftBodyHelpers.cpp     |  40 +++
 src/BulletSoftBody/btSoftBodyHelpers.h       |   5 +
 11 files changed, 440 insertions(+)
 create mode 100644 examples/ReducedDeformableDemo/BasicTest.cpp
 create mode 100644 examples/ReducedDeformableDemo/BasicTest.h
 create mode 100644 examples/SoftDemo/K_r_diag_mat.bin
 create mode 100644 examples/SoftDemo/M_r_diag_mat.bin
 create mode 100644 examples/SoftDemo/eigenvalues.bin
 create mode 100644 examples/SoftDemo/mesh.vtk
 create mode 100644 examples/SoftDemo/modes.bin

diff --git a/examples/ExampleBrowser/CMakeLists.txt b/examples/ExampleBrowser/CMakeLists.txt
index 4e40d7072..eb7565490 100644
--- a/examples/ExampleBrowser/CMakeLists.txt
+++ b/examples/ExampleBrowser/CMakeLists.txt
@@ -388,6 +388,8 @@ SET(BulletExampleBrowser_SRCS
   ../MultiBody/MultiDofDemo.h
   ../RigidBody/RigidBodySoftContact.cpp
   ../RigidBody/KinematicRigidBodyExample.cpp
+	../ReducedDeformableDemo/BasicTest.cpp
+	../ReducedDeformableDemo/BasicTest.h
   ../Constraints/TestHingeTorque.cpp
   ../Constraints/TestHingeTorque.h
   ../Constraints/ConstraintDemo.cpp
diff --git a/examples/ExampleBrowser/ExampleEntries.cpp b/examples/ExampleBrowser/ExampleEntries.cpp
index 9f8ab035c..6bbd7363e 100644
--- a/examples/ExampleBrowser/ExampleEntries.cpp
+++ b/examples/ExampleBrowser/ExampleEntries.cpp
@@ -72,6 +72,7 @@
 #include "../RoboticsLearning/R2D2GraspExample.h"
 #include "../RoboticsLearning/KukaGraspExample.h"
 #include "../RoboticsLearning/GripperGraspExample.h"
+#include "../ReducedDeformableDemo/BasicTest.h"
 #include "../InverseKinematics/InverseKinematicsExample.h"
 
 #ifdef B3_ENABLE_TINY_AUDIO
@@ -214,6 +215,10 @@ static ExampleEntry gDefaultExamples[] =
         ExampleEntry(1, "Multibody Cloth Anchor", "Deformable Multibody Anchor test", MultibodyClothAnchorCreateFunc),
         ExampleEntry(1, "Deformable-MultiBody Contact", "MultiBody and Deformable contact", DeformableMultibodyCreateFunc),
         // ExampleEntry(1, "MultiBody Baseline", "MultiBody Baseline", MultiBodyBaselineCreateFunc),
+		
+		ExampleEntry(0, "Reduced Deformabe Body"),
+		ExampleEntry(1, "BasicRD", "Simple dynamics test for the reduced deformable objects", ReducedBasicTestCreateFunc),
+		// ExampleEntry(1, "Simple Reduced Deformable Test", "Simple dynamics test for the reduced deformable objects", ReducedBasicTestCreateFunc),
         
 #ifdef INCLUDE_CLOTH_DEMOS
 		ExampleEntry(0, "Soft Body"),
diff --git a/examples/ReducedDeformableDemo/BasicTest.cpp b/examples/ReducedDeformableDemo/BasicTest.cpp
new file mode 100644
index 000000000..6d4ffd775
--- /dev/null
+++ b/examples/ReducedDeformableDemo/BasicTest.cpp
@@ -0,0 +1,286 @@
+/*
+ Bullet Continuous Collision Detection and Physics Library
+ Copyright (c) 2019 Google Inc. http://bulletphysics.org
+ This software is provided 'as-is', without any express or implied warranty.
+ In no event will the authors be held liable for any damages arising from the use of this software.
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it freely,
+ subject to the following restrictions:
+ 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+ 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+ 3. This notice may not be removed or altered from any source distribution.
+ */
+
+#include "BasicTest.h"
+///btBulletDynamicsCommon.h is the main Bullet include file, contains most common include files.
+#include "btBulletDynamicsCommon.h"
+#include "BulletSoftBody/btDeformableMultiBodyDynamicsWorld.h"
+#include "BulletSoftBody/btSoftBody.h"
+#include "BulletSoftBody/btSoftBodyHelpers.h"
+#include "BulletSoftBody/btDeformableBodySolver.h"
+#include "BulletSoftBody/btSoftBodyRigidBodyCollisionConfiguration.h"
+#include "BulletDynamics/Featherstone/btMultiBodyConstraintSolver.h"
+#include "../CommonInterfaces/CommonParameterInterface.h"
+#include <stdio.h>  //printf debugging
+
+#include "../CommonInterfaces/CommonDeformableBodyBase.h"
+#include "../Utils/b3ResourcePath.h"
+
+///The BasicTest shows the contact between volumetric deformable objects and rigid objects.
+static btScalar E = 50;
+static btScalar nu = 0.3;
+// static btScalar damping_alpha = 0.1;
+// static btScalar damping_beta = 0.01;
+static btScalar damping_alpha = 0.0;
+static btScalar damping_beta = 0.0;
+static btScalar COLLIDING_VELOCITY = 0;
+
+class BasicTest : public CommonDeformableBodyBase
+{
+    // btDeformableLinearElasticityForce* m_linearElasticity;
+    btDeformableMassSpringForce* m_massSpring;
+
+    btAlignedObjectArray<btScalar> m_eigenvalues, m_Kr, m_Mr;
+    btAlignedObjectArray<btAlignedObjectArray<btScalar> > m_modes;	// each inner array is a mode, outer array size = n_modes
+    unsigned int m_numModes;
+    bool first_step;
+
+public:
+	BasicTest(struct GUIHelperInterface* helper)
+		: CommonDeformableBodyBase(helper), m_numModes(0)
+	{
+        // m_linearElasticity = 0;
+        m_massSpring = 0;
+        first_step = true;
+	}
+	virtual ~BasicTest()
+	{
+	}
+	void initPhysics();
+
+	void exitPhysics();
+
+    // TODO: disable pick force, non-interactive for now.
+    bool pickBody(const btVector3& rayFromWorld, const btVector3& rayToWorld) {
+        return false;
+    } 
+
+	void resetCamera()
+	{
+        float dist = 20;
+        float pitch = 0;
+        float yaw = 90;
+        float targetPos[3] = {0, 3, 0};
+		m_guiHelper->resetCamera(dist, yaw, pitch, targetPos[0], targetPos[1], targetPos[2]);
+	}
+    
+    void Ctor_RbUpStack()
+    {
+        float mass = 0.5;
+        btCollisionShape* shape = new btBoxShape(btVector3(2, 2, 2));
+        btTransform startTransform;
+        startTransform.setIdentity();
+        startTransform.setOrigin(btVector3(0,-2,0));
+        btRigidBody* rb = createRigidBody(mass, startTransform, shape);
+        rb->setLinearVelocity(btVector3(0,+COLLIDING_VELOCITY, 0));
+    }
+    
+    void stepSimulation(float deltaTime)
+    {
+        // TODO: remove this. very hacky way of adding initial deformation
+        btSoftBody* psb = static_cast<btDeformableMultiBodyDynamicsWorld*>(m_dynamicsWorld)->getSoftBodyArray()[0];
+        if (first_step && !psb->m_bUpdateRtCst) {
+            // save rest length
+            btAlignedObjectArray<btScalar> rest_length;
+
+            // assign initial displacement (perturb each nodes by mode 1)
+            for (int i = 0; i < psb->m_nodes.size(); ++i)
+            {
+                for (int k = 0; k < 3; ++k)
+                {
+                    psb->m_nodes[i].m_x[k] += m_modes[0][3 * i + k];
+                }
+            }
+            first_step = false;
+        }
+        float internalTimeStep = 1. / 60.f;
+        m_dynamicsWorld->stepSimulation(deltaTime, 1, internalTimeStep);
+    }
+    
+    virtual void renderScene()
+    {
+        CommonDeformableBodyBase::renderScene();
+        btDeformableMultiBodyDynamicsWorld* deformableWorld = getDeformableDynamicsWorld();
+        
+        for (int i = 0; i < deformableWorld->getSoftBodyArray().size(); i++)
+        {
+            btSoftBody* psb = (btSoftBody*)deformableWorld->getSoftBodyArray()[i];
+            {
+                btSoftBodyHelpers::DrawFrame(psb, deformableWorld->getDebugDrawer());
+                btSoftBodyHelpers::Draw(psb, deformableWorld->getDebugDrawer(), deformableWorld->getDrawFlags());
+            }
+        }
+    }
+};
+
+void BasicTest::initPhysics()
+{
+	m_guiHelper->setUpAxis(1);
+
+	///collision configuration contains default setup for memory, collision setup
+    m_collisionConfiguration = new btSoftBodyRigidBodyCollisionConfiguration();
+
+	///use the default collision dispatcher. For parallel processing you can use a diffent dispatcher (see Extras/BulletMultiThreaded)
+	m_dispatcher = new btCollisionDispatcher(m_collisionConfiguration);
+
+	m_broadphase = new btDbvtBroadphase();
+    btDeformableBodySolver* deformableBodySolver = new btDeformableBodySolver();
+
+	btDeformableMultiBodyConstraintSolver* sol = new btDeformableMultiBodyConstraintSolver();
+    sol->setDeformableSolver(deformableBodySolver);
+	m_solver = sol;
+
+	m_dynamicsWorld = new btDeformableMultiBodyDynamicsWorld(m_dispatcher, m_broadphase, sol, m_collisionConfiguration, deformableBodySolver);
+    btVector3 gravity = btVector3(0, 0, 0);
+    m_dynamicsWorld->setGravity(gravity);
+	m_guiHelper->createPhysicsDebugDrawer(m_dynamicsWorld);
+
+    // create volumetric soft body
+    {        
+        std::string filename("../../../examples/SoftDemo/mesh.vtk");
+        btSoftBody* psb = btSoftBodyHelpers::CreateFromVtkFile(getDeformableDynamicsWorld()->getWorldInfo(), filename.c_str());
+
+        // read in eigenmodes, stiffness and mass matrices
+        unsigned int buffer_n_modes = 0;
+
+        std::string eigenvalues_file("../../../examples/SoftDemo/eigenvalues.bin");
+        btSoftBodyHelpers::readBinary(m_eigenvalues, buffer_n_modes, eigenvalues_file.c_str());
+        m_numModes = buffer_n_modes;
+
+        std::string Kr_file("../../../examples/SoftDemo/K_r_diag_mat.bin");
+        btSoftBodyHelpers::readBinary(m_Kr, buffer_n_modes, Kr_file.c_str());
+
+        std::string Mr_file("../../../examples/SoftDemo/M_r_diag_mat.bin");
+        btSoftBodyHelpers::readBinary(m_Mr, buffer_n_modes, Mr_file.c_str());
+
+        std::string modes_file("../../../examples/SoftDemo/modes.bin");
+        btSoftBodyHelpers::readBinaryMat(m_modes, 3 * psb->m_nodes.size(), buffer_n_modes, modes_file.c_str());	// default to 3D
+
+        getDeformableDynamicsWorld()->addSoftBody(psb);
+        psb->scale(btVector3(2, 2, 2));
+        psb->translate(btVector3(0, 7, 0));
+        psb->getCollisionShape()->setMargin(0.1);
+        psb->setTotalMass(0.5);
+        psb->m_cfg.kKHR = 1; // collision hardness with kinematic objects
+        psb->m_cfg.kCHR = 1; // collision hardness with rigid body
+		psb->m_cfg.kDF = 0;
+        psb->m_cfg.collisions = btSoftBody::fCollision::SDF_RD;
+        psb->m_cfg.collisions |= btSoftBody::fCollision::SDF_RDN;
+		psb->m_sleepingThreshold = 0;
+        btSoftBodyHelpers::generateBoundaryFaces(psb);
+        
+        psb->setVelocity(btVector3(0, -COLLIDING_VELOCITY, 0));
+
+        // btDeformableLinearElasticityForce* linearElasticity = new btDeformableLinearElasticityForce(100,100,0.01);
+		// m_linearElasticity = linearElasticity;
+        
+        m_massSpring = new btDeformableMassSpringForce(10.0, 0.0); //TODO: this stiffness needs to match the modes
+
+        getDeformableDynamicsWorld()->addForce(psb, m_massSpring);
+        m_forces.push_back(m_massSpring);
+    }
+    getDeformableDynamicsWorld()->setReducedModelFlag(true);
+    getDeformableDynamicsWorld()->setImplicit(false);
+    getDeformableDynamicsWorld()->setLineSearch(false);
+    getDeformableDynamicsWorld()->setUseProjection(true);
+    getDeformableDynamicsWorld()->getSolverInfo().m_deformable_erp = 0.3;
+    getDeformableDynamicsWorld()->getSolverInfo().m_deformable_maxErrorReduction = btScalar(200);
+    getDeformableDynamicsWorld()->getSolverInfo().m_leastSquaresResidualThreshold = 1e-3;
+    getDeformableDynamicsWorld()->getSolverInfo().m_splitImpulse = true;
+    getDeformableDynamicsWorld()->getSolverInfo().m_numIterations = 100;
+    // add a few rigid bodies
+    // Ctor_RbUpStack();        // TODO: no rigid body for now
+	m_guiHelper->autogenerateGraphicsObjects(m_dynamicsWorld);
+	
+    // {
+    //     SliderParams slider("Young's Modulus", &E);
+    //     slider.m_minVal = 0;
+    //     slider.m_maxVal = 2000;
+    //     if (m_guiHelper->getParameterInterface())
+    //         m_guiHelper->getParameterInterface()->registerSliderFloatParameter(slider);
+    // }
+    // {
+    //     SliderParams slider("Poisson Ratio", &nu);
+    //     slider.m_minVal = 0.05;
+    //     slider.m_maxVal = 0.49;
+    //     if (m_guiHelper->getParameterInterface())
+    //         m_guiHelper->getParameterInterface()->registerSliderFloatParameter(slider);
+    // }
+    // {
+    //     SliderParams slider("Mass Damping", &damping_alpha);
+    //     slider.m_minVal = 0;
+    //     slider.m_maxVal = 1;
+    //     if (m_guiHelper->getParameterInterface())
+    //         m_guiHelper->getParameterInterface()->registerSliderFloatParameter(slider);
+    // }
+    // {
+    //     SliderParams slider("Stiffness Damping", &damping_beta);
+    //     slider.m_minVal = 0;
+    //     slider.m_maxVal = 0.1;
+    //     if (m_guiHelper->getParameterInterface())
+    //         m_guiHelper->getParameterInterface()->registerSliderFloatParameter(slider);
+    // }
+}
+
+void BasicTest::exitPhysics()
+{
+	//cleanup in the reverse order of creation/initialization
+    removePickingConstraint();
+	//remove the rigidbodies from the dynamics world and delete them
+	int i;
+	for (i = m_dynamicsWorld->getNumCollisionObjects() - 1; i >= 0; i--)
+	{
+		btCollisionObject* obj = m_dynamicsWorld->getCollisionObjectArray()[i];
+		btRigidBody* body = btRigidBody::upcast(obj);
+		if (body && body->getMotionState())
+		{
+			delete body->getMotionState();
+		}
+		m_dynamicsWorld->removeCollisionObject(obj);
+		delete obj;
+	}
+    // delete forces
+    for (int j = 0; j < m_forces.size(); j++)
+    {
+        btDeformableLagrangianForce* force = m_forces[j];
+        delete force;
+    }
+    m_forces.clear();
+    
+	//delete collision shapes
+	for (int j = 0; j < m_collisionShapes.size(); j++)
+	{
+		btCollisionShape* shape = m_collisionShapes[j];
+		delete shape;
+	}
+	m_collisionShapes.clear();
+
+	delete m_dynamicsWorld;
+
+	delete m_solver;
+
+	delete m_broadphase;
+
+	delete m_dispatcher;
+
+	delete m_collisionConfiguration;
+}
+
+
+
+class CommonExampleInterface* ReducedBasicTestCreateFunc(struct CommonExampleOptions& options)
+{
+	return new BasicTest(options.m_guiHelper);
+}
+
+
diff --git a/examples/ReducedDeformableDemo/BasicTest.h b/examples/ReducedDeformableDemo/BasicTest.h
new file mode 100644
index 000000000..aa15e5843
--- /dev/null
+++ b/examples/ReducedDeformableDemo/BasicTest.h
@@ -0,0 +1,19 @@
+/*
+ Bullet Continuous Collision Detection and Physics Library
+ Copyright (c) 2019 Google Inc. http://bulletphysics.org
+ This software is provided 'as-is', without any express or implied warranty.
+ In no event will the authors be held liable for any damages arising from the use of this software.
+ Permission is granted to anyone to use this software for any purpose,
+ including commercial applications, and to alter it and redistribute it freely,
+ subject to the following restrictions:
+ 1. The origin of this software must not be misrepresented; you must not claim that you wrote the original software. If you use this software in a product, an acknowledgment in the product documentation would be appreciated but is not required.
+ 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
+ 3. This notice may not be removed or altered from any source distribution.
+ */
+
+#ifndef _REDUCED_BASIC_TEST_H
+#define _REDUCED_BASIC_TEST_H
+
+class CommonExampleInterface* ReducedBasicTestCreateFunc(struct CommonExampleOptions& options);
+
+#endif  //_REDUCED_BASIC_TEST_H
diff --git a/examples/SoftDemo/K_r_diag_mat.bin b/examples/SoftDemo/K_r_diag_mat.bin
new file mode 100644
index 0000000000000000000000000000000000000000..af8b7d78eafda5504669cf18a14959dce1b38983
GIT binary patch
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diff --git a/examples/SoftDemo/M_r_diag_mat.bin b/examples/SoftDemo/M_r_diag_mat.bin
new file mode 100644
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GIT binary patch
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diff --git a/examples/SoftDemo/eigenvalues.bin b/examples/SoftDemo/eigenvalues.bin
new file mode 100644
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GIT binary patch
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diff --git a/examples/SoftDemo/mesh.vtk b/examples/SoftDemo/mesh.vtk
new file mode 100644
index 000000000..cbab3e1a2
--- /dev/null
+++ b/examples/SoftDemo/mesh.vtk
@@ -0,0 +1,83 @@
+#vtk DataFile Version 2.0
+I don't think this matters
+ASCII
+DATASET UNSTRUCTURED_GRID
+POINTS 28 double
+-0.5000000000000000 -0.2500000000000000 -2.0000000000000000
+-0.5000000000000000 0.2500000000000000 -2.0000000000000000
+0.5000000000000000 -0.2500000000000000 -2.0000000000000000
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+-0.5000000000000000 0.2500000000000000 2.0000000000000000
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+0.5000000000000000 0.2500000000000000 2.0000000000000000
+-0.5000000000000000 -0.2500000000000000 1.0000000000000000
+-0.5000000000000000 -0.2500000000000000 0.0000000000000000
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+-0.5000000000000000 0.2500000000000000 0.0000000000000000
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+0.0000000000000000 0.2500000000000000 0.5000000000000000
+0.0000000000000000 0.2500000000000000 -0.5000000000000000
+0.0000000000000000 0.2500000000000000 -1.5000000000000000
+CELLS 48 192
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+4 20 10 21 26
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+4 3 27 11 19
+4 21 26 25 12
+CELL_TYPES 10
diff --git a/examples/SoftDemo/modes.bin b/examples/SoftDemo/modes.bin
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HcmV?d00001

diff --git a/src/BulletSoftBody/btSoftBodyHelpers.cpp b/src/BulletSoftBody/btSoftBodyHelpers.cpp
index f63e48f9a..fd6d5920b 100644
--- a/src/BulletSoftBody/btSoftBodyHelpers.cpp
+++ b/src/BulletSoftBody/btSoftBodyHelpers.cpp
@@ -1487,6 +1487,46 @@ void btSoftBodyHelpers::writeObj(const char* filename, const btSoftBody* psb)
 	fs.close();
 }
 
+// read in binary files
+void btSoftBodyHelpers::readBinary(btAlignedObjectArray<btScalar>& vec, unsigned int& size, const char* file)
+{
+	std::ifstream f_in(file, std::ios::in | std::ios::binary);
+	// first get size
+	f_in.read((char*)&size, sizeof(uint32_t));
+
+	// read data
+	vec.resize(size);
+	double temp;
+	for (int i = 0; i < size; i++) {
+		f_in.read((char*)&temp, sizeof(double));
+		vec[i] = btScalar(temp);
+	}
+  f_in.close();
+}
+
+void btSoftBodyHelpers::readBinaryMat(btAlignedObjectArray<btAlignedObjectArray<btScalar> >& mat, const unsigned int n_row, const unsigned int n_col, const char* file)
+{
+	std::ifstream f_in(file, std::ios::in | std::ios::binary);
+	// first get size
+	unsigned int v_size;
+	f_in.read((char*)&v_size, sizeof(uint32_t));
+	btAssert(v_size == n_row * n_col);
+
+	// read data
+	mat.resize(n_col);
+	for (int i = 0; i < n_col; ++i) 
+	{
+		mat[i].resize(n_row);
+		for (int j = 0; j < n_row; ++j)
+		{
+			double temp;
+			f_in.read((char*)&temp, sizeof(double));
+			mat[i][j] = btScalar(temp);
+		}
+	}
+  f_in.close();
+}
+
 void btSoftBodyHelpers::duplicateFaces(const char* filename, const btSoftBody* psb)
 {
 	std::ifstream fs_read;
diff --git a/src/BulletSoftBody/btSoftBodyHelpers.h b/src/BulletSoftBody/btSoftBodyHelpers.h
index 237d29761..c3a4309cf 100644
--- a/src/BulletSoftBody/btSoftBodyHelpers.h
+++ b/src/BulletSoftBody/btSoftBodyHelpers.h
@@ -144,6 +144,11 @@ struct btSoftBodyHelpers
 											bool bfacesfromtetras);
 	static btSoftBody* CreateFromVtkFile(btSoftBodyWorldInfo& worldInfo, const char* vtk_file);
 
+	// read in a binary vector
+	static void readBinary(btAlignedObjectArray<btScalar>& vec, unsigned int& size, const char* file);
+	// read in a binary matrix (must provide matrix size)
+	static void readBinaryMat(btAlignedObjectArray<btAlignedObjectArray<btScalar> >& mat, const unsigned int n_row, const unsigned int n_col, const char* file);
+
 	static void writeObj(const char* file, const btSoftBody* psb);
 
 	static void getBarycentricWeights(const btVector3& a, const btVector3& b, const btVector3& c, const btVector3& d, const btVector3& p, btVector4& bary);