How to fix the rendering of laser with respect to the UI canvas

Question

Added some UI elements inside a canvas in world-space render mode. There is an issue with the occlusion of UI elements with respect to the laser pointer. The pointer here is made from a line renderer. Here are the things that have been tried and still the pointer does not properly occlude the canvas.

• changing the hierarchy
• changing the z-order
• changing the sorting order

The source code is from Unity and is available here. There is no related script that requires modification. Seems like a setting or shader change might only be required here.

Answer 1

It is possible to write a custom shader to test for depth, but this would be a very expensive shader - and it looks like you want to use it on VR, and I would not recommend to use it like so.

Over-engineered solution and still not very cheap but cheaper solution would be to render UI onto a camera that renders into RenderTarget and passes the input to the UI.

1. Create a camera - with Redner Target output
2. Create canvas that uses Screen Space - Camera
3. Attach the camera to the Canvas
4. Put Plane in world space and use RenderTarget as material
5. Add a script that would allow passing RayCasts through RenderTarget to UI. Possible soltuion

Few notes:

• Camera needs to be disabled for as long as it is possible to save performance and only updated via Camera.Render() when UI is updated.
• This solution would still be expensive
• Adds a lot of complexity to a simple problem
• Adds the possibility to "wrap" UI around meshes

EDIT: After edit its much simpler problem!

UI is rendered at RenderQueue = 3000 you probably have unlit material as a line-renderer which has RenderQueue = 2450.

You need to create a material with RenderQueue >= 3000 for your line renderer

If you don't want to create new material, you can change it from code

// use this with caution! As this can affect other materials when run in editor!
meshRenderer.material.renderQueue = 3100;

EDIT 2: If you have URP installed you might need to change the default material to something from URP. Default material uses Legacy shader which causes issues with the Line Renderer and UI.