return function()
    local playerLookVector = nil

    local function getEntityLookVector(entity)
        -- yaw:
        --     0 => positive Z
        --     90 => negative X
        -- pitch:
        --     0 => forward
        --     90 => down
        if entity == nil or entity.yaw == nil or entity.pitch == nil then
            return {0, 0, 0, x = 0, y = 0, z = 0}
        end
        local yawr = math.rad(entity.yaw)
        local pitchr = math.rad(entity.pitch)
        local cosPitch = math.cos(pitchr)
        local x = cosPitch * -math.sin(yawr)
        local z = cosPitch *  math.cos(yawr)
        local y = -math.sin(pitchr)
        return {x, y, z, x = x, y = y, z = z}
    end

    local function updateLookVector()
        playerLookVector = getEntityLookVector(player)
        return playerLookVector
    end

    local function dotProduct3(u, v)
        return u.x * v.x + u.y * v.y + u.z * v.z
    end

    local function vec3Scale(k, v)
        return {x = k * v.x, y = k * v.y, z = k * v.z}
    end

    local function vec3Add(u, v)
        return {x = u.x + v.x, y = u.y + v.y, z = u.z + v.z}
    end

    local function vec3Abs(v)
        return math.sqrt(dotProduct3(v, v))
    end

    local function toFrontCoords(entity)
        local dotResult = dotProduct3(entity, playerLookVector)
        if dotResult >= 0.0 then
            return {x = entity.x, y = entity.y, z = entity.z, flipped = false}
        end
        local result = vec3Add(entity, vec3Scale(-2 * dotResult, playerLookVector))
        result.flipped = true
        return result
    end

    while _G.player == nil do
        os.sleep(0.05)
    end

    local cache = {}
    while _G._running do
        updateLookVector()

        for id, entry in pairs(cache) do
            if nearbyEntitiesByUUID[id] == nil then
                entry.cube.remove()
                entry.frame.remove()
                cache[id] = nil
            end
        end

        for id, entity in pairs(nearbyEntitiesByUUID) do
            if id ~= player.id then
                if cache[id] == nil then
                    cache[id] = {}
                    cache[id].cube = canvas3d.addBox(0, 0, 0)
                    cache[id].cube.setSize(0.5, 0.5, 0.5)
                    cache[id].frame = canvas3d.addFrame({ 0, 0, 0 })
                    cache[id].text = cache[id].frame.addText({ 0, 0 }, "")
                    cache[id].lookLine = canvas3d.addLine({ 0, 0, 0 }, { 0, 0, 0 }, 2, 0)
                end
                local entityFront = toFrontCoords(entity)
                local entityLook = getEntityLookVector(entity)
                local entityLookEnd = vec3Add(entityFront, entityLook)
                if entityFront.flipped then
                    cache[id].cube.setColor(0x004040FF)
                    cache[id].lookLine.setColor(0x004040FF)
                else
                    cache[id].cube.setColor(0xFFC0C0FF)
                    cache[id].lookLine.setColor(0xFFC0C0FF)
                end
                cache[id].cube.setAlpha(0x20)
                cache[id].lookLine.setAlpha(0x10)
                cache[id].cube.setDepthTested(false)
                cache[id].frame.setDepthTested(false)
                cache[id].lookLine.setDepthTested(false)
                cache[id].cube.setPosition(entityFront.x - 0.25, entityFront.y - 0.25, entityFront.z - 0.25)
                cache[id].frame.setPosition(entityFront.x, entityFront.y, entityFront.z)
                cache[id].lookLine.setPoint(1, entityFront.x, entityFront.y, entityFront.z)
                cache[id].lookLine.setPoint(2, entityLookEnd.x, entityLookEnd.y, entityLookEnd.z)
                cache[id].text.setAlpha(0xFF)
                if player.isSneaking then
                    cache[id].text.setText(entity.name .. "\n" .. textutils.serialize(entity))
                else
                    cache[id].text.setText(("%s\n|{%.2f, %.2f, %.2f}| = %.2f"):format(entity.name, entity.x, entity.y, entity.z, vec3Abs(entity)))
                end
                if entityFront.flipped then
                    cache[id].text.setColor(0x00FFFFFF)
                else
                    cache[id].text.setColor(0xFF0000FF)
                end
            end
        end
        os.sleep(0.05)
    end
end