I made a game where I create a polygone collider out of the move of the character, but i want to fill it with a sprite. I have an array with all the Vector2 to make the polygone collider, and i want to use them to create a sprite, is it possible ?
That would probably be overkill for the GPU, especially if you update it frequently. What you might look into instead, since you already have the necessary vertices and edges, would be to generate a 2D Mesh and render that into the scene. There are a bunch of resources online for procedural mesh generation and triangulation of enclosed 2D spaces.
the problem is: i can’t make it without sprite, because i need to make a sprite mask out of it. The game is about cutting an image to see the image behind. I’m really stuck 
well, i guess i can’t dodge doing more math, sigh, I wish I can have a good enough english skill to understand all the tutoriel of unity, but anyway, a big thanks to you, that will help me a lot !!