To create a Line Renderer:
By default, a Line Renderer uses the built-in Material, Default-Line. You can make many changes to the appearance of the line without changing this Material, such as editing the color gradient or width of the line.
For other effects, such as applying a texture to the line, you will need to use a different Material. If you do not want to write your own Shader for the new Material, Unity’s built-in Standard Particle Shaders work well with Line Renderers.
See Creating and using Materials for more information.
You can use the Line Renderer’s Inspector to change the Scene Editing Mode. Different Scene Editing Modes enable you to use the Scene view and the Inspector to edit the Line Renderer in different ways.
There are three Scene Editing Modes: None, Edit Points, and Create Points.
When no Scene Editing Mode is selected, you can configure and perform a simplification operation that removes unnecessary points from the Positions array.
When the Scene Editing Mode is set to Edit Points, Unity represents each point in the Line Renderer’s Positions array as a yellow sphere in the Scene view. You can move the individual points using the Move tool.
When the Scene Editing Mode is set to Create Points, you can click inside the Scene view to add new points to the end of the Line Renderer’s Positions array.