OpenVR - IVRSystem::GetControllerState 总是返回空结构

我一直在关注Kamran Bigdely-Shamloo关于如何从HTC Vive获取位置信息的文章，到目前为止效果很好。我的下一步是"听"按钮按下。我已经阅读了文档，它在这里说我需要做的就是查询IVRSystem::GetControllerState它会返回一个

"具有控制器当前状态的结构">

但是，此结构始终包含值为 0 的变量。以下函数在main函数的while (true)循环中调用。

bool CMainApplication::HandleInput()
{
SDL_Event sdlEvent;
bool bRet = false;
while ( SDL_PollEvent( &sdlEvent ) != 0 )
{
if ( sdlEvent.type == SDL_QUIT )
{
bRet = true;
}
else if ( sdlEvent.type == SDL_KEYDOWN )
{
if ( sdlEvent.key.keysym.sym == SDLK_ESCAPE 
|| sdlEvent.key.keysym.sym == SDLK_q )
{
bRet = true;
}
if( sdlEvent.key.keysym.sym == SDLK_c )
{
m_bShowCubes = !m_bShowCubes;
}
}
}
// Process SteamVR events
// Periodically returns an event of type 404 ("VREvent_SceneApplicationChanged      = 404, // data is process - The App actually drawing the scene changed (usually to or from the compositor)"
vr::VREvent_t event;
vr::VREvent_Controller_t controllerEvent;
std::chrono::milliseconds ms4;
while( m_pHMD->PollNextEvent( &event, sizeof( event ) ) )
{
ms4 = std::chrono::duration_cast<std::chrono::milliseconds>(
std::chrono::system_clock::now().time_since_epoch()
);
ProcessVREvent( &event);
printPositionalData(&event, ms4);
}
vr::VRControllerState_t state;
// Check every device attached, usually it's four devices
// Second if statement is never reached
for (int i = 0; i < 1000; i++) {
if (m_pHMD->GetControllerState(i, &state, sizeof(state))) {
dprintf("%d", i);
if (state.ulButtonPressed != 0 || state.unPacketNum != 0 || state.ulButtonTouched != 0) {
dprintf("Some action?");
}
}
}
dprintf("n");
// Process SteamVR action state
// UpdateActionState is called each frame to update the state of the actions themselves. The application
// controls which action sets are active with the provided array of VRActiveActionSet_t structs.
vr::VRActiveActionSet_t actionSet = { 0 };
actionSet.ulActionSet = m_actionsetDemo;
vr::VRInput()->UpdateActionState( &actionSet, sizeof(actionSet), 1 );
m_bShowCubes = !GetDigitalActionState( m_actionHideCubes );
vr::VRInputValueHandle_t ulHapticDevice;
if ( GetDigitalActionRisingEdge( m_actionTriggerHaptic, &ulHapticDevice ) )
{
if ( ulHapticDevice == m_rHand[Left].m_source )
{
vr::VRInput()->TriggerHapticVibrationAction( m_rHand[Left].m_actionHaptic, 0, 1, 4.f, 1.0f, vr::k_ulInvalidInputValueHandle );
}
if ( ulHapticDevice == m_rHand[Right].m_source )
{
vr::VRInput()->TriggerHapticVibrationAction( m_rHand[Right].m_actionHaptic, 0, 1, 4.f, 1.0f, vr::k_ulInvalidInputValueHandle );
}
}
vr::InputAnalogActionData_t analogData;
if ( vr::VRInput()->GetAnalogActionData( m_actionAnalongInput, &analogData, sizeof( analogData ), vr::k_ulInvalidInputValueHandle ) == vr::VRInputError_None && analogData.bActive )
{
m_vAnalogValue[0] = analogData.x;
m_vAnalogValue[1] = analogData.y;
}
m_rHand[Left].m_bShowController = true;
m_rHand[Right].m_bShowController = true;
vr::VRInputValueHandle_t ulHideDevice;
if ( GetDigitalActionState( m_actionHideThisController, &ulHideDevice ) )
{
if ( ulHideDevice == m_rHand[Left].m_source )
{
m_rHand[Left].m_bShowController = false;
}
if ( ulHideDevice == m_rHand[Right].m_source )
{
m_rHand[Right].m_bShowController = false;
}
}
for ( EHand eHand = Left; eHand <= Right; ((int&)eHand)++ )
{
vr::InputPoseActionData_t poseData;
if ( vr::VRInput()->GetPoseActionData( m_rHand[eHand].m_actionPose, vr::TrackingUniverseStanding, 0, &poseData, sizeof( poseData ), vr::k_ulInvalidInputValueHandle ) != vr::VRInputError_None
|| !poseData.bActive || !poseData.pose.bPoseIsValid )
{
m_rHand[eHand].m_bShowController = false;
}
else
{
m_rHand[eHand].m_rmat4Pose = ConvertSteamVRMatrixToMatrix4( poseData.pose.mDeviceToAbsoluteTracking );
vr::InputOriginInfo_t originInfo;
if ( vr::VRInput()->GetOriginTrackedDeviceInfo( poseData.activeOrigin, &originInfo, sizeof( originInfo ) ) == vr::VRInputError_None 
&& originInfo.trackedDeviceIndex != vr::k_unTrackedDeviceIndexInvalid )
{
std::string sRenderModelName = GetTrackedDeviceString( originInfo.trackedDeviceIndex, vr::Prop_RenderModelName_String );
if ( sRenderModelName != m_rHand[eHand].m_sRenderModelName )
{
m_rHand[eHand].m_pRenderModel = FindOrLoadRenderModel( sRenderModelName.c_str() );
m_rHand[eHand].m_sRenderModelName = sRenderModelName;
}
}
}
}
return bRet;

m_pHMD启动如下：

vr::IVRSystem *m_pHMD;
....
m_pHMD = vr::VR_Init( &eError, vr::VRApplication_Background );

我一定做错了什么，因为在下面的代码片段中，if 语句只在前四次迭代中传递，应该是控制器、vive 跟踪器、耳机和灯塔。这告诉我我能够访问这些状态，但我不知何故无法阅读信息。

for (int i = 0; i < 1000; i++) {
if (m_pHMD->GetControllerState(i, &state, sizeof(state))) {
dprintf("%d", i);
if (state.ulButtonPressed != 0 || state.unPacketNum != 0 || state.ulButtonTouched != 0) {
dprintf("Some action?");
}
}

我无法想象这是一个错误，所以我的猜测是我的配置有问题，或者我做了错误的查询。 任何帮助将不胜感激！