Quick answer: Unity Canvas Overlay disappearing after a camera change? The Canvas mode quietly switched to Screen Space - Camera; the new camera reference is null or non-rendering.

Switching the active camera at runtime makes the HUD vanish. The HUD canvas was on Screen Space - Camera with the old camera.

Overlay vs Camera Mode

Screen Space - Overlay renders without any camera — immune to camera switches. Screen Space - Camera renders through a specific camera — sensitive to active camera.

Update Camera Reference

canvas.worldCamera = newCamera;
canvas.planeDistance = 1.0f;

Re-assign after the swap so the canvas renders through the new active camera.

World Space for 3D HUDs

World Space canvases attach to a world position. Cameras render them like any 3D object. Best for in-game UI panels.

Camera Stack Sort

If using URP camera stacking, the camera stack determines who renders the overlay UI. Misconfigured stacks hide the canvas.

Verifying

HUD visible across all camera switches. No frames where UI disappears.

“Overlay needs no camera. Camera mode needs an updated reference after every switch.”

Default HUDs to Screen Space - Overlay unless you need 3D camera-aware UI — one less wire to break.