hololens里使用UGUI canvas的坑

add canvas check if the event system is added, add holo input module to event system;

scale the canvas；

set canvas to world-space;

set canvas camera to hololens camera(!!!!)

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here, the problem showed.: you are not able to change the camera of the canvas

 with a warning telling you that the camera will be updated to uiraycast camera?

why？what is uiraycast camera?

i didn't get the answer by searching on google 

well, the solution is to click on the inputmanager, and you will see the script named focus manager on it.

and then , you will see a uiraycast camera open to set.

set it to main camera.

and run, the camera of the canvas will be automatedly updated to it

)