How do you exclude something from i, v in pairs?

Soooooo.... I wanna create a new part whenever the players are close enough to a part in the workspace. It applies to all the parts in the workspace. When I used i,v in pairs, it won't work as there is Camera, Terrain in it. How do I exclude them out from i,v in pairs?

local plr = game.Workspace:FindFirstChild(script.Parent.Parent.Name)
print(plr)
print(plr.Parent)

while true do
	for i, v in pairs(game.Workspace:GetChildren()) do
		local mag = (plr.HumanoidRootPart.Position - v.Position).magnitude
		if mag < 20 then
			break
		end
		end
wait(0.01)
end

**Not the entire script. But it's the part that is being asked. :)