Tried using sprite outline shader with LineRenderer, works surprisingly well References:Sprite shader source: https://forum.unity.com/threads/help-to-find-an-asset-solution.755273/#post-5246960 (2nd shader in that post)Forum topic: https://forum.unity.com/threads/achieve-a-stroke-transparent-effect-with-the-line-renderer.999682/

Quick test shader for this thread https://forum.unity.com/threads/smooth-filling-of-the-2d-pipe-with-texture.845848/#post-5584480 Shader source:https://github.com/UnityCommunity/UnityLibrary/blob/master/Assets/Shaders/2D/Patterns/ScrollingFill.shader Sample fbx file (used in screenshot)https://github.com/unitycoder/BlogUploads/blob/master/models/lineuv.FBX