Circular Camera Mask?

I want to make a circular minimap using a camera attached to my player. The problem, obviously, is that the cameras are square. What's an easy way to make my camera circular? Can I mask it under a UI Image?

 

I've not used masks personally but there are a few asset store items that seem to do this sort of stencil/masking stuff.

You could also make a geometric circle in a 3D program (like Blender) and set the UVs so they are centered in the UV space, then use a RenderTexture as the source texture to feed the camera's view to that texture, then place it in view of your main camera.

 

What is your minimap constructed of?

Is it a UI element that just shows an image?

Is it a camera view of another part of the scene (like a birdseye, or you have some separate GameObjects elsewhere in the scene that represent it)?

Are you rendering a seconds camera's view to a RenderTexture, and displaying that somewhere?