Edit the collider’s geometry

You can edit a colliderAn invisible shape that is used to handle physical collisions for an object. A collider doesn’t need to be exactly the same shape as the object’s mesh - a rough approximation is often more efficient and indistinguishable in gameplay. More info
See in Glossary’s geometry manually or have Unity generate its shape automatically.

Unity automatically generates a collider’s geometry when you drag a spriteA 2D graphic objects. If you are used to working in 3D, Sprites are essentially just standard textures but there are special techniques for combining and managing sprite textures for efficiency and convenience during development. More info
See in Glossary into the sceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary and add a Collider 2D component to it. The generated collider shape matches the outline of the sprite as close as possible.

To edit the collider’s shape:

1. Select Edit Collider in the Inspector window to edit the collider’s geometry. You can also access the collider’s editing mode from the Tools overlay in the Scene view window.
   
2. To move an existing vertex, select and hold it, then move it to a new location.
3. To create a new vertex, hover your cursor over the outline of the collider’s shape. A dot shows the position of the cursor on the collider’s geometry. Click on the dot to create a new vertex at that position.
4. To remove a vertex, hold Ctrl (macOS:Cmd) while hovering your cursor over the edges of the collider’s geometry, which turn red. Click the red edges to remove the vertex that connects them.
5. Exit the collider editing mode by selecting Edit Collider in the InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
   See in Glossary window or Tools overlay again.