Is there a way to render models over the UI

i have VR scene, where i have a cube inside a canvas with render mode ->World space
133052-vr-ui-camera.png

I need to rotate the cube (or any other mesh) that cube over the UI.

One issue i am facing is the mesh and UI are going inside each other.

There are two solution that i can think of now is 
 1)Move the cube in z axis but that cant be done as it can be any model which means it can have different height and length.
2) Use Two camera and use layer and culling mask 

but i want to avoid both the solution,Now what can be done to fix this issue
i just want that object to be rendered above the UI even if both ui and object are at same position

hello, can you test using change the render mode to screen space - camera? that will make the canvas to scale to always fit the camera size and you can adjust the plane distance for making sure its always behind.