Bullet Collision Detection & Physics Library
btDefaultSoftBodySolver.cpp
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1 /*
2 Bullet Continuous Collision Detection and Physics Library
3 Copyright (c) 2003-2006 Erwin Coumans http://continuousphysics.com/Bullet/
4 
5 This software is provided 'as-is', without any express or implied warranty.
6 In no event will the authors be held liable for any damages arising from the use of this software.
7 Permission is granted to anyone to use this software for any purpose,
8 including commercial applications, and to alter it and redistribute it freely,
9 subject to the following restrictions:
10 
11 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.
12 2. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
13 3. This notice may not be removed or altered from any source distribution.
14 */
15 
19 
23 
25 {
26  // Initial we will clearly need to update solver constants
27  // For now this is global for the cloths linked with this solver - we should probably make this body specific
28  // for performance in future once we understand more clearly when constants need to be updated
30 }
31 
33 {
34 }
35 
36 // In this case the data is already in the soft bodies so there is no need for us to do anything
38 {
39 }
40 
42 {
43  m_softBodySet.copyFromArray(softBodies);
44 }
45 
47 {
48  for (int i = 0; i < m_softBodySet.size(); i++)
49  {
50  btSoftBody *psb = (btSoftBody *)m_softBodySet[i];
51  if (psb->isActive())
52  {
53  psb->integrateMotion();
54  }
55  }
56 } // updateSoftBodies
57 
59 {
60  return true;
61 }
62 
64 {
65  // Solve constraints for non-solver softbodies
66  for (int i = 0; i < m_softBodySet.size(); ++i)
67  {
68  btSoftBody *psb = static_cast<btSoftBody *>(m_softBodySet[i]);
69  if (psb->isActive())
70  {
71  psb->solveConstraints();
72  }
73  }
74 } // btDefaultSoftBodySolver::solveConstraints
75 
77 {
78  // Currently only support CPU output buffers
79  // TODO: check for DX11 buffers. Take all offsets into the same DX11 buffer
80  // and use them together on a single kernel call if possible by setting up a
81  // per-cloth target buffer array for the copy kernel.
82 
84  {
85  const btAlignedObjectArray<btSoftBody::Node> &clothVertices(softBody->m_nodes);
86  int numVertices = clothVertices.size();
87 
88  const btCPUVertexBufferDescriptor *cpuVertexBuffer = static_cast<btCPUVertexBufferDescriptor *>(vertexBuffer);
89  float *basePointer = cpuVertexBuffer->getBasePointer();
90 
91  if (vertexBuffer->hasVertexPositions())
92  {
93  const int vertexOffset = cpuVertexBuffer->getVertexOffset();
94  const int vertexStride = cpuVertexBuffer->getVertexStride();
95  float *vertexPointer = basePointer + vertexOffset;
96 
97  for (int vertexIndex = 0; vertexIndex < numVertices; ++vertexIndex)
98  {
99  btVector3 position = clothVertices[vertexIndex].m_x;
100  *(vertexPointer + 0) = (float)position.getX();
101  *(vertexPointer + 1) = (float)position.getY();
102  *(vertexPointer + 2) = (float)position.getZ();
103  vertexPointer += vertexStride;
104  }
105  }
106  if (vertexBuffer->hasNormals())
107  {
108  const int normalOffset = cpuVertexBuffer->getNormalOffset();
109  const int normalStride = cpuVertexBuffer->getNormalStride();
110  float *normalPointer = basePointer + normalOffset;
111 
112  for (int vertexIndex = 0; vertexIndex < numVertices; ++vertexIndex)
113  {
114  btVector3 normal = clothVertices[vertexIndex].m_n;
115  *(normalPointer + 0) = (float)normal.getX();
116  *(normalPointer + 1) = (float)normal.getY();
117  *(normalPointer + 2) = (float)normal.getZ();
118  normalPointer += normalStride;
119  }
120  }
121  }
122 } // btDefaultSoftBodySolver::copySoftBodyToVertexBuffer
123 
125 {
126  softBody->defaultCollisionHandler(otherSoftBody);
127 }
128 
129 // For the default solver just leave the soft body to do its collision processing
131 {
132  softBody->defaultCollisionHandler(collisionObjectWrap);
133 } // btDefaultSoftBodySolver::processCollision
134 
136 {
137  for (int i = 0; i < m_softBodySet.size(); ++i)
138  {
139  btSoftBody *psb = m_softBodySet[i];
140 
141  if (psb->isActive())
142  {
143  psb->predictMotion(timeStep);
144  }
145  }
146 }
virtual void solveConstraints(float solverdt)
Solve constraints for a set of soft bodies.
virtual void predictMotion(float solverdt)
Predict motion of soft bodies into next timestep.
void defaultCollisionHandler(const btCollisionObjectWrapper *pcoWrap)
The btAlignedObjectArray template class uses a subset of the stl::vector interface for its methods It...
void integrateMotion()
virtual int getVertexStride() const
Return the vertex stride in number of floats between vertices.
virtual BufferTypes getBufferType() const =0
Return the type of the vertex buffer descriptor.
virtual int getNormalOffset() const
Return the vertex offset in floats from the base pointer.
bool m_updateSolverConstants
Variable to define whether we need to update solver constants on the next iteration.
const btScalar & getY() const
Return the y value.
Definition: btVector3.h:563
void copyFromArray(const btAlignedObjectArray &otherArray)
tNodeArray m_nodes
Definition: btSoftBody.h:691
virtual void copyBackToSoftBodies(bool bMove=true)
Copy necessary data back to the original soft body source objects.
const btScalar & getZ() const
Return the z value.
Definition: btVector3.h:565
virtual void optimize(btAlignedObjectArray< btSoftBody *> &softBodies, bool forceUpdate=false)
Optimize soft bodies in this solver.
void solveConstraints()
void predictMotion(btScalar dt)
virtual int getNormalStride() const
Return the vertex stride in number of floats between vertices.
virtual void updateSoftBodies()
Perform necessary per-step updates of soft bodies such as recomputing normals and bounding boxes...
btAlignedObjectArray< btSoftBody * > m_softBodySet
btVector3 can be used to represent 3D points and vectors.
Definition: btVector3.h:80
int size() const
return the number of elements in the array
virtual bool checkInitialized()
Ensure that this solver is initialized.
virtual void processCollision(btSoftBody *, const btCollisionObjectWrapper *)
virtual float * getBasePointer() const
Return the base pointer in memory to the first vertex.
The btSoftBody is an class to simulate cloth and volumetric soft bodies.
Definition: btSoftBody.h:70
const btScalar & getX() const
Return the x value.
Definition: btVector3.h:561
virtual void copySoftBodyToVertexBuffer(const btSoftBody *const softBody, btVertexBufferDescriptor *vertexBuffer)
virtual int getVertexOffset() const
Return the vertex offset in floats from the base pointer.