Merge pull request #7934 from AndrewMeadows/trim-convex-hulls

reduce number of points in unreasonable convex hulls

libraries/physics/src/PhysicalEntitySimulation.cpp

@@ -217,6 +217,12 @@ void PhysicalEntitySimulation::getObjectsToAddToPhysics(VectorOfMotionStates& re
         } else if (entity->isReadyToComputeShape()) {
             ShapeInfo shapeInfo;
             entity->computeShapeInfo(shapeInfo);
+            int numPoints = shapeInfo.getMaxNumPoints();
+            if (numPoints > MAX_HULL_POINTS) {
+                qWarning() << "convex hull with" << numPoints
+                    << "points for entity" << entity->getName()
+                    << "at" << entity->getPosition() << " will be reduced";
+            }
             btCollisionShape* shape = ObjectMotionState::getShapeManager()->getShape(shapeInfo);
             if (shape) {
                 EntityMotionState* motionState = new EntityMotionState(shape, entity);

libraries/physics/src/ShapeFactory.cpp

@@ -10,6 +10,7 @@
 //
 
 #include <glm/gtx/norm.hpp>
+#include <BulletCollision/CollisionShapes/btShapeHull.h>
 
 #include <SharedUtil.h> // for MILLIMETERS_PER_METER
 
@@ -64,6 +65,22 @@ btConvexHullShape* ShapeFactory::createConvexHull(const QVector<glm::vec3>& poin
         correctedPoint = (points[i] - center) * relativeScale + center;
         hull->addPoint(btVector3(correctedPoint[0], correctedPoint[1], correctedPoint[2]), false);
     }
+
+    if (points.size() > MAX_HULL_POINTS) {
+        // create hull approximation
+        btShapeHull shapeHull(hull);
+        shapeHull.buildHull(margin);
+        // we cannot copy Bullet shapes so we must create a new one...
+        btConvexHullShape* newHull = new btConvexHullShape();
+        const btVector3* newPoints = shapeHull.getVertexPointer();
+        for (int i = 0; i < shapeHull.numVertices(); ++i) {
+            newHull->addPoint(newPoints[i], false);
+        }
+        // ...and delete the old one
+        delete hull;
+        hull = newHull;
+    }
+
     hull->recalcLocalAabb();
     return hull;
 }

libraries/shared/src/ShapeInfo.cpp

@@ -99,6 +99,18 @@ uint32_t ShapeInfo::getNumSubShapes() const {
     }
     return 1;
 }
+
+int ShapeInfo::getMaxNumPoints() const {
+    int numPoints = 0;
+    for (int i = 0; i < _points.size(); ++i) {
+        int n = _points[i].size();
+        if (n > numPoints) {
+            numPoints = n;
+        }
+    }
+    return numPoints;
+}
+
 float ShapeInfo::computeVolume() const {
     const float DEFAULT_VOLUME = 1.0f;
     float volume = DEFAULT_VOLUME;

libraries/shared/src/ShapeInfo.h

@@ -22,6 +22,10 @@
 
 const float MIN_SHAPE_OFFSET = 0.001f; // offsets less than 1mm will be ignored
 
+// Bullet has a mesh generation util for convex shapes that we used to
+// trim convex hulls with many points down to only 42 points.
+const int MAX_HULL_POINTS = 42;
+
 enum ShapeType {
     SHAPE_TYPE_NONE,
     SHAPE_TYPE_BOX,
@@ -61,6 +65,7 @@ public:
 
     void clearPoints () { _points.clear(); }
     void appendToPoints (const QVector<glm::vec3>& newPoints) { _points << newPoints; }
+    int getMaxNumPoints() const;
 
     float computeVolume() const;
 

libraries/shared/src/StreamUtils.cpp

@@ -23,7 +23,7 @@ void StreamUtil::dump(std::ostream& s, const QByteArray& buffer) {
     while (i < buffer.size()) {
         for(int j = 0; i < buffer.size() && j < row_size; ++j) {
             char byte = buffer[i];
-            s << hex_digits[(byte >> 4) & 0x0f] << hex_digits[byte & 0x0f] << " ";
+            s << hex_digits[(byte >> 4) & 0x0f] << hex_digits[byte & 0x0f] << ' ';
             ++i;
         }
         s << "\n";
@@ -31,21 +31,21 @@ void StreamUtil::dump(std::ostream& s, const QByteArray& buffer) {
 }
 
 std::ostream& operator<<(std::ostream& s, const glm::vec3& v) {
-    s << "<" << v.x << " " << v.y << " " << v.z << ">";
+    s << '(' << v.x << ' ' << v.y << ' ' << v.z << ')';
     return s;
 }
 
 std::ostream& operator<<(std::ostream& s, const glm::quat& q) {
-    s << "<" << q.x << " " << q.y << " " << q.z << " " << q.w << ">";
+    s << '(' << q.x << ' ' << q.y << ' ' << q.z << ' ' << q.w << ')';
     return s;
 }
 
 std::ostream& operator<<(std::ostream& s, const glm::mat4& m) {
-    s << "[";
+    s << '[';
     for (int j = 0; j < 4; ++j) {
-        s << " " << m[0][j] << " " << m[1][j] << " " << m[2][j] << " " << m[3][j] << ";";
+        s << ' ' << m[0][j] << ' ' << m[1][j] << ' ' << m[2][j] << ' ' << m[3][j] << ';';
     }
-    s << "  ]";
+    s << " ]";
     return s;
 }
 
@@ -69,54 +69,37 @@ QDataStream& operator>>(QDataStream& in, glm::quat& quaternion) {
 #include <QDebug>
 
 QDebug& operator<<(QDebug& dbg, const glm::vec2& v) {
-    dbg.nospace() << "{type='glm::vec2'"
-        ", x=" << v.x <<
-        ", y=" << v.y <<
-        "}";
+    dbg.nospace() << '(' << v.x << ", " << v.y << ')';
     return dbg;
 }
 
 QDebug& operator<<(QDebug& dbg, const glm::vec3& v) {
-    dbg.nospace() << "{type='glm::vec3'"
-        ", x=" << v.x <<
-        ", y=" << v.y <<
-        ", z=" << v.z <<
-        "}";
+    dbg.nospace() << '(' << v.x << ", " << v.y << ", " << v.z << ')';
     return dbg;
 }
 
 QDebug& operator<<(QDebug& dbg, const glm::vec4& v) {
-    dbg.nospace() << "{type='glm::vec4'"
-        ", x=" << v.x <<
-        ", y=" << v.y <<
-        ", z=" << v.z <<
-        ", w=" << v.w <<
-        "}";
+    dbg.nospace() << '(' << v.x << ", " << v.y << ", " << v.z << ", " << v.w << ')';
     return dbg;
 }
 
 QDebug& operator<<(QDebug& dbg, const glm::quat& q) {
-    dbg.nospace() << "{type='glm::quat'"
-        ", x=" << q.x <<
-        ", y=" << q.y <<
-        ", z=" << q.z <<
-        ", w=" << q.w <<
-        "}";
+    dbg.nospace() << '(' << q.x << ", " << q.y << ", " << q.z << ", " << q.w << ')';
     return dbg;
 }
 
 QDebug& operator<<(QDebug& dbg, const glm::mat4& m) {
-    dbg.nospace() << "{type='glm::mat4', [";
+    dbg.nospace() << '[';
     for (int j = 0; j < 4; ++j) {
         dbg << ' ' << m[0][j] << ' ' << m[1][j] << ' ' << m[2][j] << ' ' << m[3][j] << ';';
     }
-    return dbg << " ]}";
+    return dbg << " ]";
 }
 
 QDebug& operator<<(QDebug& dbg, const QVariantHash& v) {
-    dbg.nospace() << "[";
+    dbg.nospace() << "[ ";
     for (QVariantHash::const_iterator it = v.constBegin(); it != v.constEnd(); it++) {
-        dbg << it.key() << ":" << it.value();
+        dbg << it.key() << ':' << it.value();
     }
     return dbg << " ]";
 }