c++ - Bullet Physics - 从网格创建 ShapeHull

Question

我正在尝试将我用于使用 OpenGL 绘制的网格数据加载到 Bullet 引擎中。

问题是我不相信网格数据实际上是从指针中读取的。因此物理世界不匹配，“角色 Controller ”从地板上掉下来。

渲染的世界很好，所以我知道 OpenGL 数据很好。

这是我用来将数据传输到 OpenGL 的 Controller 类的函数。

我在这里遗漏了什么吗？

谢谢 - 这是我正在使用的代码:

void PhysicsController::AddStaticBasicMesh(PhysicsObject* NewObject, bool ReducePolygonCount = true)
{
   btTriangleMesh* OriginalTriangleMesh = new btTriangleMesh();
   btIndexedMesh* NewMesh = new btIndexedMesh();
   NewMesh->m_triangleIndexBase = (unsigned char *)NewObject->Indices;
   NewMesh->m_triangleIndexStride = 3 * sizeof(unsigned int);
   NewMesh->m_vertexBase = (unsigned char *)NewObject->Vertices;
   NewMesh->m_vertexStride = 3 * sizeof(float);
   NewMesh->m_numVertices = NewObject->NumberOfVertices;
   NewMesh->m_numTriangles = NewObject->NumberOfTriangles;
   OriginalTriangleMesh->addIndexedMesh((*NewMesh));
   btConvexShape* NewStaticMesh = new btConvexTriangleMeshShape(OriginalTriangleMesh);
   btConvexHullShape* ReducedPolygonStaticMesh;

   if (ReducePolygonCount == true) {
      btShapeHull* HullOfOriginalShape = new btShapeHull(NewStaticMesh);
      btScalar CurrentMargin = NewStaticMesh->getMargin();
      HullOfOriginalShape->buildHull(CurrentMargin);
      ReducedPolygonStaticMesh = new btConvexHullShape();

      for (int i = 0; i < HullOfOriginalShape->numVertices(); i++) {
         ReducedPolygonStaticMesh->addPoint(HullOfOriginalShape->getVertexPointer()[i], false);
      }

      ReducedPolygonStaticMesh->recalcLocalAabb();
      /*

      Find out what this line does.

      ReducedPolygonStaticMesh->initializePolyhedralFeatures();

      */

      StaticShapes.push_back(ReducedPolygonStaticMesh);
      btDefaultMotionState* StaticMotionState = new btDefaultMotionState((*NewObject->PositionAndOrientation));
      btRigidBody::btRigidBodyConstructionInfo StaticMeshRigidBodyInfo(0, StaticMotionState, ReducedPolygonStaticMesh, btVector3(0.0f, 0.0f, 0.0f));
      btRigidBody* StaticRigidMesh = new btRigidBody(StaticMeshRigidBodyInfo);
      NewObject->Body = StaticRigidMesh;
      StaticRigidMesh->setCollisionFlags(StaticRigidMesh->getCollisionFlags() | btCollisionObject::CF_STATIC_OBJECT);
      MainPhysicsWorld->addRigidBody(StaticRigidMesh, btBroadphaseProxy::StaticFilter, btBroadphaseProxy::CharacterFilter | btBroadphaseProxy::DefaultFilter);
      AllRigidBodies.push_back(NewObject);
      StaticRigidMesh->setUserPointer(AllRigidBodies[AllRigidBodies.size() - 1]);
      delete HullOfOriginalShape;
      delete NewStaticMesh;
   } else {
      StaticShapes.push_back(NewStaticMesh);;
      btDefaultMotionState* StaticMotionState = new btDefaultMotionState((*NewObject->PositionAndOrientation));
      btRigidBody::btRigidBodyConstructionInfo StaticMeshRigidBodyInfo(0, StaticMotionState, NewStaticMesh, btVector3(0.0f, 0.0f, 0.0f));
      btRigidBody* StaticRigidMesh = new btRigidBody(StaticMeshRigidBodyInfo);
      NewObject->Body = StaticRigidMesh;
      StaticRigidMesh->setCollisionFlags(StaticRigidMesh->getCollisionFlags() | btCollisionObject::CF_STATIC_OBJECT);
      MainPhysicsWorld->addRigidBody(StaticRigidMesh, btBroadphaseProxy::StaticFilter, btBroadphaseProxy::CharacterFilter | btBroadphaseProxy::DefaultFilter);
      AllRigidBodies.push_back(NewObject);
      StaticRigidMesh->setUserPointer(AllRigidBodies[AllRigidBodies.size() - 1]);
   }
}

Answer 1

也许，这不是您正在寻找的答案，但您可能可以使用 btConvexHullShape，如 Bullet 文档中所建议的那样？

http://bulletphysics.org/Bullet/BulletFull/classbtConvexTriangleMeshShape.html

Nevertheless, most users should use the much better performing btConvexHullShape instead.

并使用addPoint逐一添加顶点，文档中也有提到:

http://bulletphysics.org/Bullet/BulletFull/classbtConvexHullShape.html

It is easier to not pass any points in the constructor, and just add one point at a time, using addPoint

我知道回答“只是使用其他东西”而不是回答原始问题是不好的。

同样，您将通过这种方式复制顶点。

但是，如果您才刚刚开始学习一些新技术，您可能希望先让一切正常运行，然后再逐步返回到您的原始设计可能会更容易。

另一个好主意是使用调试抽屉 并实际查看您的网格的外观。

前段时间我为 OpenGL ES 2.0 创建了一个，也许它会有所帮助: https://github.com/kmuzykov/custom-opengl-es-game-engine/blob/master/Engine/Physics/KMPhysicsDebugDrawer.cpp