Hi there, I was playing around trying to get my HMD to display both eyes. In BP I used a console command node with ‘HMD mirror mode 0’ followed by another node with ‘fullscreen’. It made my preview black, restart and changing back to HMD mirror mode 0 didn’t work. I put the nodes into my player pawn at begin play, though fullscreen has no effect. The HMD still works and it builds ok, just the preview window is black.
Any help is appreciated. - Thanks!
Yeah I do this on occasion, you can restart the editor and see if that helps, if not just delete the saved and intermediate folder. I forget which one you actually need to delete but deleting both of them will be fine as the engine will recreate them when you open up the project again
Thanks for the reply, deleting both didn’t help seem to help. Other projects are previewing fine. So it’s in a config somewhere…
I had this problem before and made a thread about it. You should’ve used the search function.
The issue is that you tried using a Oculus command with the HTC Vive.
The only solution i found is create a new project and copy/Migrate all the stuff from your project in it.
Try deleating your Saved and Intermediate folders in your project’s folder and see if that helps.
Unfortunately deleting the folders doesn’t seem to work. @Rukasu, yes migrating does resolve it, thanks. I don’t know how I missed that, I guess I was looking on the answer hub.
Same happened to me.
I was looking for a way to display only one Mirror undistorted, I have missed the fact that it was a Oculus Only command.
Sadly, I do not have a alternative to get the Single undistorted mirror on the Vive for you. I am still looking for a solution.
Glad I could help.
This worked for me.
The mirror mode console command for the vive is acutally hmd mirror 0/1/2 (no mode in there!)
Actually when I tried to package the project the black screen came back so I went back to my project file and deleted everything bar the content folder. Now it gives me the preview window if I package in development mode but the black window if I package in shipping. I’m releasing my game this week so I guess I will just have to use the development version. Is there any real drawback releasing a development build as apposed to the shipping build?
i deleted the saved and intermediate folders. now my project is gone. 
This was the issue for me still in 4.16, thanks! What a gotcha! No “mode” with vive!
Deleting folders didn’t work for me. (Also I didn’t delete them @komocode only moved them and renamed, moved them back when it didn’t help)
deleting the intermediate folder did the trick for me 