Model

Sets the level of detail on the model for experiences with instance streaming enabled.

When set to StreamingMesh, a lower resolution "imposter" mesh (colored, coarse mesh that wraps around all child parts of the model) renders outside the streaming radius.

When set to Disabled or Automatic, lower resolution meshes will not be displayed.

Controls how Models are streamed in and out when instance streaming is enabled. Behavior depends on the selected enum. Has no effect when streaming is not enabled.

This property should only be changed in Studio via the Properties window when streaming is enabled, or in Scripts, but never in LocalScripts (doing so can result in undefined behavior).

Points to the primary part of the Model. The primary part is the BasePart that acts as the physical reference for the pivot of the model. That is, when parts within the model are moved due to physical simulation or other means, the pivot will move in sync with the primary part.

Note that Models do not have PrimaryPart set by default. If you are creating a model that needs to be acted upon by physics, you should manually set this property in Studio or within a script. If the primary part is not set, the pivot will remain at the same location in world space, even if parts within the model are moved.

Also note that when setting this property, it must be a BasePart that is a descendant of the model. If you try to set Model.PrimaryPart to a BasePart that is not a descendant of the model, it will be set to that part but reset to nil during the next simulation step — this is legacy behavior to support scripts which assume they can temporarily set the primary part to a BasePart which isn't a descendant of the model.

The general rule for models is that:

• Models whose parts are joined together via physical joints such as WeldConstraints or Motor6Ds should have a primary part assigned. For example, Roblox character models have their Model.PrimaryPart set to the HumanoidRootPart by default.
• Static (usually Anchored) models which stay in one place unless a script explicitly moves them don't require a Model.PrimaryPart and tend not to benefit from having one set.

-- Create a dice model with two halves and attach them together
local diceModel = Instance.new("Model")
diceModel.Name = "ChanceCube"

local diceTop = Instance.new("Part")
diceTop.Size = Vector3.new(4, 2, 4)
diceTop.Position = Vector3.new(0, 1, 0)
diceTop.Color = Color3.new(0, 0, 1)
diceTop.Parent = diceModel

local diceBottom = diceTop:Clone()
diceBottom.Position = Vector3.new(0, -1, 0)
diceBottom.Color = Color3.new(1, 0, 0)
diceBottom.Parent = diceModel

local weld = Instance.new("WeldConstraint")
weld.Part0 = diceTop
weld.Part1 = diceBottom
weld.Parent = diceModel

-- Put the dice up in the air above the workspace origin (does not require a primary part)
diceModel.Parent = workspace
diceModel:PivotTo(CFrame.new(0, 10, 0))

-- Assign the primary part before physical simulation
-- Without this line, the script will always output the same thing and the bounding box of the model will not change orientation
diceModel.PrimaryPart = diceTop

-- Wait a bit before rolling the dice (let it settle onto the floor)
for i = 5, 1, -1 do
	print("Rolling dice in...", i)
	task.wait(1)
end

diceTop:ApplyAngularImpulse(Vector3.new(15000, 1000, 5000))
diceTop:ApplyImpulse(Vector3.new(0, 3000, 0))
task.wait(1)

-- Wait for the roll to complete
while diceTop.AssemblyLinearVelocity.Magnitude > 0.1 or diceTop.AssemblyAngularVelocity.Magnitude > 0.1 do
	task.wait()
end

-- Get the dice orientation, impacted by the primary part
local orientation = diceModel:GetBoundingBox()
if orientation.YVector.Y > 0.5 then
	print("It's the boy!")
else
	print("It's his mother!")
end

Setting this property in the Properties window will scale the model as though Model/ScaleTo was called on it, scaling all descendant Instances in the model, such as materials, images, and the 3D geometry of parts, so that the model has the specified scale factor relative to its original size.

This property is only available in Studio and will throw an error if used in a Script or LocalScript. Model/ScaleTo and Model/GetScale should be used from scripts.

This property determines where the pivot of a Model which does not have a set Model.PrimaryPart is located. If the Model does have a PrimaryPart, the pivot of the Model is equal to the pivot of that primary part instead, and this WorldPivot property is ignored.

For a newly created Model, its pivot will be treated as the center of the bounding box of its contents until the first time its Model.WorldPivot property is set. Once the world pivot is set for the first time, it is impossible to restore this initial behavior.

Most commonly, moving the model with the Studio tools, or with model movement functions such as PVInstance:PivotTo() and Model:MoveTo(), will set the world pivot and thus end this new model behavior.

The purpose of this behavior is to allow Luau code to get a sensible pivot simply by creating a new model and parenting objects to it, avoiding the need to explicitly set Model.WorldPivot every time you create a model in code.

local Workspace = game:GetService("Workspace")

local model = Instance.new("Model")
Workspace.BluePart.Parent = model
Workspace.RedPart.Parent = model
model.Parent = Workspace

print(model:GetPivot())  -- Currently equal to the center of the bounding box containing "BluePart" and "RedPart"

model:PivotTo(CFrame.new(0, 10, 0))  -- This works without needing to explicitly set "model.WorldPivot"

local function resetPivot(model)
	local boundsCFrame = model:GetBoundingBox()
	if model.PrimaryPart then
		model.PrimaryPart.PivotOffset = model.PrimaryPart.CFrame:ToObjectSpace(boundsCFrame)
	else
		model.WorldPivot = boundsCFrame
	end
end

resetPivot(script.Parent)

Sets this model to be persistent for the specified player. Persistent models stay present for the player regardless of streaming settings or conditions.

ModelStreamingMode must be set to PersistentPerPlayer for behavior to be changed as a result of addition.

Parameters

Returns

This function returns a description of a volume that contains all BasePart children within a Model. The volume's orientation is based on the orientation of the PrimaryPart, and matches the selection box rendered in Studio when the model is selected. Mirroring the behavior of Terrain:FillBlock(), it returns a CFrame representing the center of that bounding box and a Vector3 representing its size.

If there is no PrimaryPart for the model, the bounding box will be aligned to the world axes.

local Workspace = game:GetService("Workspace")

local model = Workspace.Model
local part = Workspace.Part
local orientation, size = model:GetBoundingBox()

-- Resize and position part equal to bounding box of model
part.Size = size
part.CFrame = orientation

Returns

Returns the size of the smallest bounding box that contains all of the BaseParts in the Model. If Model.PrimaryPart exists then the bounding box will be aligned to that part. If a primary part has not been set then the function will chose a part in the model to align the bounding box to. As the selection of this part is not deterministic it is recommended to set a Model.PrimaryPart to get consistent results with this function.

Note this function only returns the size of the smallest bounding box, and the developer must employ their own method to obtain the position of the bounding box.

Returns

local model = Instance.new("Model")
model.Parent = workspace

local RNG = Random.new()

for _ = 1, 5 do
	local part = Instance.new("Part")
	part.Anchored = true
	part.Size = Vector3.new(RNG:NextNumber(0.05, 5), RNG:NextNumber(0.05, 5), RNG:NextNumber(0.05, 5))
	part.Parent = model
end

print(model:GetExtentsSize())

When this method is called from a Script, it returns all the Player objects that this model is persistent for. When called from a LocalScript, this method only checks if this model is persistent for the LocalPlayer.

Returns

Models contain a persistent canonical scale factor, which starts out at 1 for newly created models and changes as the model is scaled by calling Model/ScaleTo. This function returns the current canonical scale factor of the model.

The current scale factor does not directly impact the size of Instances under the model. It is used for content authoring and scripting purposes to remember how the model has been scaled relative to its original size.

Within a given session, the model will cache the precise original size information of the descendant Instances after the first Model/ScaleTo call. This means that calling ScaleTo(x) followed by ScaleTo(1) will get you back exactly the original configuration of the model with no floating point drift. Avoiding floating point drift is the motivation for having a ScaleTo function instead of a ScaleBy function.

The scale factor does impact engine behavior in one way: The scale factor of a model will be applied to joint offsets of animations played on an AnimationController under that model, so that animated rigs will correctly play back animations even when scaled.

Returns

local CollectionService = game:GetService("CollectionService")
local ReplicatedStorage = game:GetService("ReplicatedStorage")

-- Find all the models with the tag we want to replace
local items = CollectionService:GetTagged("Tree")
local newModel = ReplicatedStorage.FancyTreeReplacementModel
for _, item in items do
	-- Make the new item and scale / position it where the old one was
	local newItem = newModel:Clone()
	newItem:ScaleTo(item:GetScale())
	newItem:PivotTo(item:GetPivot())

	-- Add the same tag to the replacement
	CollectionService:AddTag(newItem, "Tree")

	-- Delete the old item and parent the new one
	newItem.Parent = item.Parent
	item:Destroy()
end

Moves the PrimaryPart to the given position. If a primary part has not been specified, the root part of the model will be used, but the root part is not deterministic and it is recommended that you always set a primary part when using MoveTo().

If there are any obstructions where the model is to be moved, such as Terrain or other BaseParts, the model will be moved vertically upward until there is nothing in the way. If this behavior is not desired, PVInstance:PivotTo() should be used instead.

Note that rotation is not preserved when moving a model with MoveTo(). It is recommended to use either TranslateBy() or PVInstance:PivotTo() if the current rotation of the model needs to be preserved.

Parameters

Returns

local START_POSITION = Vector3.new(-20, 10, 0)
local END_POSITION = Vector3.new(0, 10, 0)

local model = Instance.new("Model")
model.Parent = workspace

local part1 = Instance.new("Part")
part1.Size = Vector3.new(4, 4, 4)
part1.Position = START_POSITION
part1.Anchored = true
part1.BrickColor = BrickColor.new("Bright yellow")
part1.Parent = model

local part2 = Instance.new("Part")
part2.Size = Vector3.new(2, 2, 2)
part2.Position = START_POSITION + Vector3.new(0, 3, 0)
part2.Anchored = true
part2.BrickColor = BrickColor.new("Bright blue")
part2.Parent = model

model.PrimaryPart = part1
model.Parent = workspace

local obstruction = Instance.new("Part")
obstruction.Name = "Obstruction"
obstruction.Size = Vector3.new(10, 10, 10)
obstruction.Position = Vector3.new(0, 10, 0)
obstruction.Anchored = true
obstruction.BrickColor = BrickColor.new("Bright green")
obstruction.Parent = workspace

task.wait(3)

model:MoveTo(END_POSITION)

Makes this model no longer persistent for the specified player. This does not guarantee the model will immediately be removed for the player; after calling this method, the model will be treated as Atomic for that player and will remain present as long as it is within the target streaming radius.

ModelStreamingMode must be set to PersistentPerPlayer for behavior to be changed as a result of removal.

Parameters

Returns

Models contain a persistent canonical scale factor, which starts out at 1 for newly created models. This function scales the model, around the pivot location, relative to how it would look at a scale factor of 1. To accomplish this it does two things:

• Sets the current scale factor of the model to the specified value
• Resizes and repositions all descendant Instances accordingly

The scaling of locations is done around the pivot location.

All "geometric" properties of descendant Instances will be scaled. That obviously includes the sizes of parts, but here are some other examples of properties which are scaled:

• The length of joints like WeldConstraints, and Class.Rope|Ropes
• Physical velocities and forces like Hinge.MaxServoTorque
• Visual properties like sizes of particle emitters
• Other length properties like Sound.RollOffMinDistance

Parameters

Returns

Shifts a Model by the given Vector3 offset, preserving the model's orientation. If another BasePart or Terrain already exists at the new position then the Model will overlap said object.

The translation is applied in world space rather than object space, meaning even if the model's parts are orientated differently it will still move along the standard axis.

Parameters

Returns

local START_POSITION = Vector3.new(-20, 10, 0)
local END_POSITION = Vector3.new(0, 10, 0)

local model = Instance.new("Model")

local part1 = Instance.new("Part")
part1.Size = Vector3.new(4, 4, 4)
part1.CFrame = CFrame.new(START_POSITION) * CFrame.Angles(0, math.rad(45), 0)
part1.Anchored = true
part1.BrickColor = BrickColor.new("Bright yellow")
part1.Parent = model

local part2 = Instance.new("Part")
part2.Size = Vector3.new(2, 2, 2)
part2.CFrame = part1.CFrame * CFrame.new(0, 3, 0)
part2.Anchored = true
part2.BrickColor = BrickColor.new("Bright blue")
part2.Parent = model

model.PrimaryPart = part1
model.Parent = workspace

local obstruction = Instance.new("Part")
obstruction.Name = "Obstruction"
obstruction.Size = Vector3.new(10, 10, 10)
obstruction.Position = Vector3.new(0, 10, 0)
obstruction.Transparency = 0.5
obstruction.Anchored = true
obstruction.BrickColor = BrickColor.new("Bright green")
obstruction.Parent = workspace

task.wait(3)
-- use TranslateBy to shift the model into the obstruction
model:TranslateBy(END_POSITION - START_POSITION)