Visualize

local function visualize(startPos, endPos, color) --draw the ray
    local distance = (endPos - startPos).magnitude
    local rayPart = Instance.new("Part", workspace)
    rayPart.Name          = "RayPart"
    rayPart.BrickColor    = BrickColor.new(color)
    rayPart.Transparency  = 0.5
    rayPart.Anchored      = true
    rayPart.CanCollide    = false
    rayPart.TopSurface    = Enum.SurfaceType.Smooth
    rayPart.BottomSurface = Enum.SurfaceType.Smooth
    rayPart.formFactor    = Enum.FormFactor.Custom
    rayPart.Size          = Vector3.new(0.2, 0.2, distance)
    rayPart.CFrame        = CFrame.new(endPos, startPos) * CFrame.new(0, 0, -distance/2)
    table.insert(parts, rayPart)
    game:GetService("Debris"):AddItem(rayPart, 1/60)
end