Example on drawing random dice from a bag in Tabletop Simulator

tabletop.lua

-- Example on how to take a die from a shuffled bag
-- and put the die on its space.
-- A reply to this question on Reddit:
-- https://www.reddit.com/r/tabletopsimulator/comments/eft9h6/scripting_how_to_randomly_choose_objects_in_a_bag/

d20_guid = "2f4af6"
d12_guid = "d90df3"
d10_guid = "327eec"
 d8_guid = "213698"
 d4_guid = "0b8595"

dice_guids = { d20_guid, d12_guid, d10_guid, d8_guid, d4_guid }

bag_guid = "bb4f30"

-- Use the guid as the key and positions as values in
-- in the positions table. When we draw a die from the
-- bag we use this lookup table to see where we shuld
-- place it.
positions = {
  -- x, y, z for each die.
  -- y is the height over the table and setting it to
  -- a number higher than zero will make it fall down
  -- to the board
  [d20_guid] = {-3.05, 3, 3.04},
  [d12_guid] = {-1.02, 3, 3.05},
  [d10_guid] = { 1.01, 3, 3.05},
  [ d8_guid] = { 3.04, 3, 3.05},
  [ d4_guid] = { 5.07, 3, 3.05}
}

-- The buttons are small go-stones that we
-- use to create the button-labels on
draw_button_guid = "bba56e"
reset_button_guid = "c43e43"

function onLoad()
  button_setup("Draw random dice", draw_button_guid, 'drawDice', 7000)
  button_setup("Reset", reset_button_guid, 'resetDice', 4000)
end

function drawDice()
  math.randomseed(os.time())
  -- If we want to use yield to wait/sleep in the waitFrames
  -- function we need to start a Coroutine. See:
  -- https://api.tabletopsimulator.com/base/#startluacoroutine
  startLuaCoroutine(Global, "drawDiceCoroutine")
end

function drawDiceCoroutine()
  local bag = getObjectFromGUID(bag_guid)
  bag.shuffle()
  -- find out how many dice there are in the bag
  local dice = bag.getObjects()
  for i=1, #dice do
    -- take the first die
     local die = bag.takeObject()
    -- look up the position based on the guid
     local die_position = positions[die.guid]
     die.setPositionSmooth(die_position)
     waitFrames(200)
  end

  -- https://api.tabletopsimulator.com/base/#startluacoroutine
  return 1 -- otherwise scripting error
end

function resetDice()
  local bag = getObjectFromGUID(bag_guid)
  for _, die_guid in ipairs(dice_guids) do
    local die = getObjectFromGUID(die_guid)
    bag.putObject(die)
  end
end

function waitFrames(frames)
  while frames > 0 do
    coroutine.yield(0)
    frames = frames - 1
  end
end

function button_setup(label, guid, function_name, width, height, font_size)
  local button = getObjectFromGUID(guid)
  if button == nil then
    print("Button '", label, "' does not exist, skipping it...")
    return
  end
  local button_parameters = {}
  button_parameters.click_function = function_name
  button_parameters.label = label
  button_parameters.function_owner = nil
  button_parameters.position = { 0, 0.2, 0 }
  button_parameters.rotation = {0, 180, 0}
  button_parameters.width = width
  button_parameters.height = 1500
  button_parameters.font_size = 800
  button.createButton(button_parameters)
  return button
end