[Feature] Intro of Direct Preview in Unreal Engine from 3.1.94 Early Access

[MariosBikos]

 

Hi all,

We recently released an Early Access version of Wave SDK 3.1.94. This version comes with several new Experimental Features for content developers and one of them is Direct Preview for Unreal Engine.

 

While creating content for Vive Focus/ Focus Plus, developers need to test and tweak their project to make sure that everything works properly. However this process is often time-consuming as developers need to repeatedly build, deploy and install APKs spending time waiting during the development stage.

That’s why we introduced the Direct Preview feature which enables you to skip the building process and directly preview your content on your AIO HMD via Wi-fi. You can rapidly preview and iterate on your scene using Unreal’s VR Preview Play mode while Direct Preview will stream the rendered frames to your Vive AIO device. Headpose, Control input, gestures, and similar input is sent from the device to the computer. You are able to effectively preview the app without needing to go through a time-consuming build and deploy process.

Here is a video showing the steps:

 

INSTRUCTIONS
You can find detailed instructions HERE about Direct Preview.

Here's what you need to do:

• Integrate the WaveVR plugin of the WaveSDK to your Unreal Engine Project according to the instructions here.
• Connect the HMD to your PC/laptop with a USB cable and turn on the HMD. Make sure that the proximity sensor of the HMD is always covered to keep the HMD awake(otherwise it will go to sleep).
• Find the IP of your HMD using the adb command "adb shell ifconfig"
• Copy and paste the IP to the Wave VR Project Settings. Also make sure that the Connect Type is set to Wi-fi.

• Install the Direct Preview APK to your HMD using the Wave VR Menu option "Install Device APK". This will install automatically the wvr_plugins_directpreview_agent_unreal.apk that lives in the {YourProjectName}\Plugins\WaveVR\Prebuilt\DirectPreview\deviceAPK folder.

• Verify that the apk was installed successfully by checking the Library of installed apps on your HMD.
• Start the DPServer using the WaveVR Tab Menu option "Start DPServer". You will notice a console window opening that will show you logs of setting up the server.

• Now your server is up and running we need to connect the HMD to it. To do that we need to start the apk we installed earlier. Go ahead and run the "Start Device APK" command from the Unreal Menu tab. This will automatically start the apk on your HMD(since the HMD is connected to your PC).

• Once you start the apk on your HMD you will notice a screen showing the message "Connecting...". You should also see the dpServer console window is updating with logs, showing that a client is connected to the server. 
• You can now disconnect the headset from the PC as the streaming will take place via Wifi. 
• Now start "Play in VR Preview" from the Unreal Engine menu. This will start a preview of your VR application and if you enabled "Enable Preview Image" in your WaveVR Project settings you should see the same result rendered/streamed on your HMD wirelessly. 
• That's it! If you now try to move the headset, the VR Preview window will update accordingly. You can always stop the VR Preview, modify your scene layout or work on your project and then start the VR Preview again to see the updated results quickly on your HMD. This way you don't have to deploy an apk and wait for things to be compiled just to preview a simple change, saving you previous development time.

 

ISSUES/NOTES

• Make sure that your PC/Laptop and your HMD are both connected to the same network domain.
• If what you see on your HMD during the Direct Preview looks blurry, you may need to adjust the image size sent to the HMD by changing the Unreal Engine window size in Editor Preferences > Level Editor - Play in Unreal Editor. So for example, if your Unreal Editor VR Preview window is too small, the image sent to the HMD will need to upscale and this will cause pixelation. 
• At the moment, your Unreal Engine Project folder must be in your Window C Drive(and not an external hard drive), otherwise Direct Preview may not work at all (we are working on a fix for this issue).
• If you notice that only the left or right eye view is rendered on the HMD during the Direct Preview Mode or none of them are rendered at all, that's because Direct Preview needs high bandwidth for streaming, otherwise it is possible to lose frames. However, we provide an update frequency option in the WaveVR Project Settings so developers can adjust the FPS according to their bandwidth and reduce the FPS accordingly. Also restarting both the apk and the dpServer.exe application can help with the loss of rendering in the HMD during Direct Preview. Keep in mind that the FPS option here has to do with the number of frames sent from the dpServer(PC) to the APK(HMD).  
• If you can't see the dpServer.exe window after trying to start it from the WaveVR Menu option button, you can always start it manually by running {YourProjectName}\WaveVR\Prebuilt\DirectPreview\dpServer.exe. Similarly if the Direct Preview apk is not installed automatically after clicking on the Install Device APK option, you can always install it manually using adb install command. The apk lives inside the plugin:  {YourProjectName}\Plugins\WaveVR\Prebuilt\DirectPreview\deviceAPK\wvr_plugins_directpreview_agent_unreal.apk.
• If you start the DPServer and the window is opening and closing immediately there is probably an error. Try to run the .exe manually with cmd and if you notice that the log is complaining about nvidia drivers try to update to the latest nvidia drivers + restart your PC if you already have the latest drivers.
• Remember that you only need to start the dpServer and the Direct Preview apk once and it will keep running in the background. Of course feel free to restart it if you notice that something went wrong.

 

Please give it a go and let us know about your thoughts in the comments. 

 

 

[MDV Games]

@MariosBikos_HTC

Great guide! Thanks a lot!