2.典型的physx程序启动流程

在应用程序中使用PhysXSDK，首先要初始化一些全局对象。当程序结束时，释放这些对象。（经过测试，physx的内存管理做得非常好了，几乎没有资源泄漏情况）。

Foundation and Physics

首先在程序启动的时候，需要创建一个Foundation对象(俗称地基，表演的舞台) static PxDefaultErrorCallback gDefaultErrorCallback;//错误处理接口，可根据需要继承重写 static PxDefaultAllocator gDefaultAllocatorCallback;//内存分配器,可根据需要继承重写，比如用jemalloc,tcmalloc mFoundation = PxCreateFoundation(PX_FOUNDATION_VERSION, gDefaultAllocatorCallback, gDefaultErrorCallback); if(!mFoundation) fatalError("PxCreateFoundation failed!"); 创建顶层PxPhysics对象 bool recordMemoryAllocations = true; mPvd = PxCreatePvd(*gFoundation); PxPvdTransport* transport = PxDefaultPvdSocketTransportCreate(PVD_HOST, 5425, 10); mPvd->connect(*transport,PxPvdInstrumentationFlag::eALL); mPhysics = PxCreatePhysics(PX_PHYSICS_VERSION, *mFoundation, PxTolerancesScale(), recordMemoryAllocations, mPvd); if(!mPhysics) fatalError("PxCreatePhysics failed!"); //PVD是physx调试器 //PxTolerancesScale根据项目设置缩放比例 //recordMemoryAllocations是否进行内存分析，这样pvd可以调试

SDK建议

如果平台上内存有限，将PhysX链接为一个静态库时，要避免链接一些特性，节约内存。目前可选的功能有: Articulations Height Fields Cloth Particles 如果应用程序需要此功能的一个子集，建议调用PxCreateBasePhysics而不是PxCreatePhysics，然后手动注册所需的组件。

physx::PxPhysics* customCreatePhysics(physx::PxU32 version, physx::PxFoundation& foundation, const physx::PxTolerancesScale& scale, bool trackOutstandingAllocations physx::PxPvd* pvd) { physx::PxPhysics* physics = PxCreateBasePhysics(version, foundation, scale, trackOutstandingAllocations, pvd); if(!physics) return NULL; PxRegisterArticulations(*physics); PxRegisterHeightFields(*physics); return physics; }

注意，只有在当静态库链接的时候，这么做才会节约内存。

释放资源

mPhysics->release(); mFoundation->release();

典型启动和退出流程，参见官方helloworld示例

void initPhysics(bool interactive) { //创建Foundation gFoundation = PxCreateFoundation(PX_FOUNDATION_VERSION, gAllocator, gErrorCallback); //创建pvd gPvd = PxCreatePvd(*gFoundation); PxPvdTransport* transport = PxDefaultPvdSocketTransportCreate(PVD_HOST, 5425, 10); gPvd->connect(*transport,PxPvdInstrumentationFlag::eALL); //顶层physx gPhysics = PxCreatePhysics(PX_PHYSICS_VERSION, *gFoundation, PxTolerancesScale(),true,gPvd); //场景属性 PxSceneDesc sceneDesc(gPhysics->getTolerancesScale()); sceneDesc.gravity = PxVec3(0.0f, -9.81f, 0.0f); gDispatcher = PxDefaultCpuDispatcherCreate(2); sceneDesc.cpuDispatcher = gDispatcher; sceneDesc.filterShader = PxDefaultSimulationFilterShader; gScene = gPhysics->createScene(sceneDesc); } //释放流程，调用release void cleanupPhysics(bool interactive) { PX_UNUSED(interactive); gScene->release(); gDispatcher->release(); gPhysics->release(); PxPvdTransport* transport = gPvd->getTransport(); gPvd->release(); transport->release(); gFoundation->release(); printf("SnippetHelloWorld done.\n"); }