Bullet Collision Detection & Physics Library: btTriangleMeshShape.cpp Source File

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btTriangleMeshShape.cpp
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1/*
2Bullet Continuous Collision Detection and Physics Library
3Copyright (c) 2003-2009 Erwin Coumans http://bulletphysics.org
4
5This software is provided 'as-is', without any express or implied warranty.
6In no event will the authors be held liable for any damages arising from the use of this software.
7Permission is granted to anyone to use this software for any purpose,
8including commercial applications, and to alter it and redistribute it freely,
9subject to the following restrictions:
10
111. 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.
122. Altered source versions must be plainly marked as such, and must not be misrepresented as being the original software.
133. This notice may not be removed or altered from any source distribution.
14*/
15
16#include "btTriangleMeshShape.h"
17#include "LinearMath/btVector3.h"
18#include "LinearMath/btQuaternion.h"
19#include "btStridingMeshInterface.h"
20#include "LinearMath/btAabbUtil2.h"
21#include "BulletCollision/CollisionShapes/btCollisionMargin.h"
22
23btTriangleMeshShape::btTriangleMeshShape(btStridingMeshInterface* meshInterface)
24 : btConcaveShape(), m_meshInterface(meshInterface)
25{
26 m_shapeType = TRIANGLE_MESH_SHAPE_PROXYTYPE;
27 if (meshInterface->hasPremadeAabb())
28 {
29 meshInterface->getPremadeAabb(&m_localAabbMin, &m_localAabbMax);
30 }
31 else
32 {
33 recalcLocalAabb();
34 }
35}
36
37btTriangleMeshShape::~btTriangleMeshShape()
38{
39}
40
41 void btTriangleMeshShape::getAabb(const btTransform& trans, btVector3& aabbMin, btVector3& aabbMax) const
42{
43 btVector3 localHalfExtents = btScalar(0.5) * (m_localAabbMax - m_localAabbMin);
44 localHalfExtents += btVector3(getMargin(), getMargin(), getMargin());
45 btVector3 localCenter = btScalar(0.5) * (m_localAabbMax + m_localAabbMin);
46
47 btMatrix3x3 abs_b = trans.getBasis().absolute();
48
49 btVector3 center = trans(localCenter);
50
51 btVector3 extent = localHalfExtents.dot3(abs_b[0], abs_b[1], abs_b[2]);
52 aabbMin = center - extent;
53 aabbMax = center + extent;
54}
55
56 void btTriangleMeshShape::recalcLocalAabb()
57{
58 for (int i = 0; i < 3; i++)
59 {
60 btVector3 vec(btScalar(0.), btScalar(0.), btScalar(0.));
61 vec[i] = btScalar(1.);
62 btVector3 tmp = localGetSupportingVertex(vec);
63 m_localAabbMax[i] = tmp[i] + m_collisionMargin;
64 vec[i] = btScalar(-1.);
65 tmp = localGetSupportingVertex(vec);
66 m_localAabbMin[i] = tmp[i] - m_collisionMargin;
67 }
68}
69
70 class SupportVertexCallback : public btTriangleCallback
71{
72 btVector3 m_supportVertexLocal;
73
74public:
75 btTransform m_worldTrans;
76 btScalar m_maxDot;
77 btVector3 m_supportVecLocal;
78
79 SupportVertexCallback(const btVector3& supportVecWorld, const btTransform& trans)
80 : m_supportVertexLocal(btScalar(0.), btScalar(0.), btScalar(0.)), m_worldTrans(trans), m_maxDot(btScalar(-BT_LARGE_FLOAT))
81
82 {
83 m_supportVecLocal = supportVecWorld * m_worldTrans.getBasis();
84 }
85
86 virtual void processTriangle(btVector3* triangle, int partId, int triangleIndex)
87 {
88 (void)partId;
89 (void)triangleIndex;
90 for (int i = 0; i < 3; i++)
91 {
92 btScalar dot = m_supportVecLocal.dot(triangle[i]);
93 if (dot > m_maxDot)
94 {
95 m_maxDot = dot;
96 m_supportVertexLocal = triangle[i];
97 }
98 }
99 }
100
101 btVector3 GetSupportVertexWorldSpace()
102 {
103 return m_worldTrans(m_supportVertexLocal);
104 }
105
106 btVector3 GetSupportVertexLocal()
107 {
108 return m_supportVertexLocal;
109 }
110};
111
112 void btTriangleMeshShape::setLocalScaling(const btVector3& scaling)
113{
114 m_meshInterface->setScaling(scaling);
115 recalcLocalAabb();
116}
117
118 const btVector3& btTriangleMeshShape::getLocalScaling() const
119{
120 return m_meshInterface->getScaling();
121}
122
123//#define DEBUG_TRIANGLE_MESH
124
125 void btTriangleMeshShape::processAllTriangles(btTriangleCallback* callback, const btVector3& aabbMin, const btVector3& aabbMax) const
126{
127 struct FilteredCallback : public btInternalTriangleIndexCallback
128 {
129 btTriangleCallback* m_callback;
130 btVector3 m_aabbMin;
131 btVector3 m_aabbMax;
132
133 FilteredCallback(btTriangleCallback* callback, const btVector3& aabbMin, const btVector3& aabbMax)
134 : m_callback(callback),
135 m_aabbMin(aabbMin),
136 m_aabbMax(aabbMax)
137 {
138 }
139
140 virtual void internalProcessTriangleIndex(btVector3* triangle, int partId, int triangleIndex)
141 {
142 if (TestTriangleAgainstAabb2(&triangle[0], m_aabbMin, m_aabbMax))
143 {
144 //check aabb in triangle-space, before doing this
145 m_callback->processTriangle(triangle, partId, triangleIndex);
146 }
147 }
148 };
149
150 FilteredCallback filterCallback(callback, aabbMin, aabbMax);
151
152 m_meshInterface->InternalProcessAllTriangles(&filterCallback, aabbMin, aabbMax);
153}
154
155 void btTriangleMeshShape::calculateLocalInertia(btScalar mass, btVector3& inertia) const
156{
157 (void)mass;
158 //moving concave objects not supported
159 btAssert(0);
160 inertia.setValue(btScalar(0.), btScalar(0.), btScalar(0.));
161}
162
163 btVector3 btTriangleMeshShape::localGetSupportingVertex(const btVector3& vec) const
164{
165 btVector3 supportVertex;
166
167 btTransform ident;
168 ident.setIdentity();
169
170 SupportVertexCallback supportCallback(vec, ident);
171
172 btVector3 aabbMax(btScalar(BT_LARGE_FLOAT), btScalar(BT_LARGE_FLOAT), btScalar(BT_LARGE_FLOAT));
173
174 processAllTriangles(&supportCallback, -aabbMax, aabbMax);
175
176 supportVertex = supportCallback.GetSupportVertexLocal();
177
178 return supportVertex;
179}
btAabbUtil2.h
TestTriangleAgainstAabb2
bool TestTriangleAgainstAabb2(const btVector3 *vertices, const btVector3 &aabbMin, const btVector3 &aabbMax)
conservative test for overlap between triangle and aabb
Definition btAabbUtil2.h:54
TRIANGLE_MESH_SHAPE_PROXYTYPE
@ TRIANGLE_MESH_SHAPE_PROXYTYPE
Definition btBroadphaseProxy.h:54
btCollisionMargin.h
btQuaternion.h
dot
btScalar dot(const btQuaternion &q1, const btQuaternion &q2)
Calculate the dot product between two quaternions.
Definition btQuaternion.h:888
btScalar
float btScalar
The btScalar type abstracts floating point numbers, to easily switch between double and single floati...
Definition btScalar.h:314
BT_LARGE_FLOAT
#define BT_LARGE_FLOAT
Definition btScalar.h:316
btAssert
#define btAssert(x)
Definition btScalar.h:153
btStridingMeshInterface.h
btTriangleMeshShape.h
btVector3.h
SupportVertexCallback
Definition btTriangleMeshShape.cpp:71
SupportVertexCallback::m_supportVertexLocal
btVector3 m_supportVertexLocal
Definition btTriangleMeshShape.cpp:72
SupportVertexCallback::GetSupportVertexWorldSpace
btVector3 GetSupportVertexWorldSpace()
Definition btTriangleMeshShape.cpp:101
SupportVertexCallback::m_supportVecLocal
btVector3 m_supportVecLocal
Definition btTriangleMeshShape.cpp:77
SupportVertexCallback::GetSupportVertexLocal
btVector3 GetSupportVertexLocal()
Definition btTriangleMeshShape.cpp:106
SupportVertexCallback::SupportVertexCallback
SupportVertexCallback(const btVector3 &supportVecWorld, const btTransform &trans)
Definition btTriangleMeshShape.cpp:79
SupportVertexCallback::m_worldTrans
btTransform m_worldTrans
Definition btTriangleMeshShape.cpp:75
SupportVertexCallback::m_maxDot
btScalar m_maxDot
Definition btTriangleMeshShape.cpp:76
SupportVertexCallback::processTriangle
virtual void processTriangle(btVector3 *triangle, int partId, int triangleIndex)
Definition btTriangleMeshShape.cpp:86
btCollisionShape::m_shapeType
int m_shapeType
Definition btCollisionShape.h:30
btConcaveShape
The btConcaveShape class provides an interface for non-moving (static) concave shapes.
Definition btConcaveShape.h:39
btConcaveShape::getMargin
virtual btScalar getMargin() const
Definition btConcaveShape.h:52
btConcaveShape::m_collisionMargin
btScalar m_collisionMargin
Definition btConcaveShape.h:41
btInternalTriangleIndexCallback
Definition btTriangleCallback.h:31
btMatrix3x3
The btMatrix3x3 class implements a 3x3 rotation matrix, to perform linear algebra in combination with...
Definition btMatrix3x3.h:50
btMatrix3x3::absolute
btMatrix3x3 absolute() const
Return the matrix with all values non negative.
Definition btMatrix3x3.h:1028
btStridingMeshInterface
The btStridingMeshInterface is the interface class for high performance generic access to triangle me...
Definition btStridingMeshInterface.h:28
btStridingMeshInterface::hasPremadeAabb
virtual bool hasPremadeAabb() const
Definition btStridingMeshInterface.h:68
btStridingMeshInterface::getScaling
const btVector3 & getScaling() const
Definition btStridingMeshInterface.h:80
btStridingMeshInterface::setScaling
void setScaling(const btVector3 &scaling)
Definition btStridingMeshInterface.h:84
btStridingMeshInterface::InternalProcessAllTriangles
virtual void InternalProcessAllTriangles(btInternalTriangleIndexCallback *callback, const btVector3 &aabbMin, const btVector3 &aabbMax) const
Definition btStridingMeshInterface.cpp:23
btTransform
The btTransform class supports rigid transforms with only translation and rotation and no scaling/she...
Definition btTransform.h:30
btTransform::getBasis
btMatrix3x3 & getBasis()
Return the basis matrix for the rotation.
Definition btTransform.h:109
btTransform::setIdentity
void setIdentity()
Set this transformation to the identity.
Definition btTransform.h:167
btTriangleCallback
The btTriangleCallback provides a callback for each overlapping triangle when calling processAllTrian...
Definition btTriangleCallback.h:24
btTriangleCallback::processTriangle
virtual void processTriangle(btVector3 *triangle, int partId, int triangleIndex)=0
btTriangleMeshShape::~btTriangleMeshShape
virtual ~btTriangleMeshShape()
Definition btTriangleMeshShape.cpp:37
btTriangleMeshShape::getAabb
virtual void getAabb(const btTransform &t, btVector3 &aabbMin, btVector3 &aabbMax) const
getAabb returns the axis aligned bounding box in the coordinate frame of the given transform t.
Definition btTriangleMeshShape.cpp:41
btTriangleMeshShape::m_localAabbMin
btVector3 m_localAabbMin
Definition btTriangleMeshShape.h:27
btTriangleMeshShape::btTriangleMeshShape
btTriangleMeshShape(btStridingMeshInterface *meshInterface)
btTriangleMeshShape constructor has been disabled/protected, so that users will not mistakenly use th...
Definition btTriangleMeshShape.cpp:23
btTriangleMeshShape::recalcLocalAabb
void recalcLocalAabb()
Definition btTriangleMeshShape.cpp:56
btTriangleMeshShape::m_localAabbMax
btVector3 m_localAabbMax
Definition btTriangleMeshShape.h:28
btTriangleMeshShape::calculateLocalInertia
virtual void calculateLocalInertia(btScalar mass, btVector3 &inertia) const
Definition btTriangleMeshShape.cpp:155
btTriangleMeshShape::processAllTriangles
virtual void processAllTriangles(btTriangleCallback *callback, const btVector3 &aabbMin, const btVector3 &aabbMax) const
Definition btTriangleMeshShape.cpp:125
btTriangleMeshShape::localGetSupportingVertex
virtual btVector3 localGetSupportingVertex(const btVector3 &vec) const
Definition btTriangleMeshShape.cpp:163
btTriangleMeshShape::setLocalScaling
virtual void setLocalScaling(const btVector3 &scaling)
Definition btTriangleMeshShape.cpp:112
btTriangleMeshShape::m_meshInterface
btStridingMeshInterface * m_meshInterface
Definition btTriangleMeshShape.h:29
btTriangleMeshShape::getLocalScaling
virtual const btVector3 & getLocalScaling() const
Definition btTriangleMeshShape.cpp:118
btVector3
btVector3 can be used to represent 3D points and vectors.
Definition btVector3.h:82
btVector3::dot
btScalar dot(const btVector3 &v) const
Return the dot product.
Definition btVector3.h:229
btVector3::dot3
btVector3 dot3(const btVector3 &v0, const btVector3 &v1, const btVector3 &v2) const
Definition btVector3.h:720
btVector3::setValue
void setValue(const btScalar &_x, const btScalar &_y, const btScalar &_z)
Definition btVector3.h:640