UnityMobilePaint not working on actual device

Question

I'm using https://github.com/unitycoder/UnityMobilePaint library for drawing in unity I have imported one scene from this to my unity project its working fine on unity editor but not woking when running on actual android device for android device MobilePaint.cs file line no 532

if (!Physics.Raycast(cam.ScreenPointToRay(Input.mousePosition), out hit, Mathf.Infinity, paintLayerMask)) { wentOutside = true; return; }

always return false for editor return true