how to find the polygons within 1 from the point. if the vertices are not on this radius.
If you are using raycast to determine the point you can get the triangle that was hit. (Olnly usable with mesh colliders)
Unity has no concepts of quads like in your picture shown, so you have to go with triangles.
RaycastHit.triangleIndex find only 1 triangle, but I need to find all, spherecastall return 1 triangle too.