function scene()
    s = Scene() { background_color = Color(.1, .1, .2),
                  camera = Perspective(45) { transform = Translate(2*y) } }

    s:add_entities({
        Plane(),
        --Sphere() { transform = Translate(y + 5*z) }
    })

    s:add_lights({
        Light() { color = white,
                  transform = Translate(6*y - 3*x) }
    })

    for i = 1,30 do
        local v = Vector(3*math.cos(i/30*2*math.pi), 5 + 3*math.sin(i/30*2*math.pi), 15)
        local tf = Translate(v) * Scale(.2, .2, .2)
        s:add_entity(Sphere() { transform = tf })
    end

    s:add_entity(Sphere() { transform = Translate(100*z) * Scale(20,20,20) })

    return s
end