solid-modeling.md

title	description
Solid Modeling	Solid modeling is the process of joining parts together to form complex shapes.

Solid modeling is the process of joining parts together in unique ways to form more complex shapes known as unions or intersections. You can perform four solid modeling operations using the tools within the Model tab.

Tool	Shortcut	Description
[Union](#unioning-parts)	ShiftCtrlG (Windows) Shift⌘G (Mac)	Join two or more parts together to form a single solid union.
[Intersect](#intersecting-parts)	ShiftCtrlI (Windows) Shift⌘I (Mac)	Intersect overlapping parts into a single solid intersection.
[Negate](#negating-parts)	ShiftCtrlN (Windows) Shift⌘N (Mac)	Negate parts, useful for making holes and indentations.
[Separate](#separating-unions-or-intersections)	ShiftCtrlU (Windows) Shift⌘U (Mac)	Separate the union or intersection back into its individual parts.

Unioning Parts

The Union tool joins two or more parts together to form a single solid Class.UnionOperation. By default, a new union respects the Class.BasePart.Color|Color property of each of its parts, although you can enable its Class.PartOperation.UsePartColor|UsePartColor property to change the entire union to a specific color.

To combine parts together into a union:

1. Select all parts to join together.

2. Click the Union button. All of the parts combine into one solid Class.UnionOperation with the name Union.

   

Intersecting Parts

The Intersect tool intersects overlapping parts into a single solid Class.IntersectOperation. By default, the face colors of the resulting intersection are borrowed from the Class.BasePart.Color|Color property of the original parts, although you can enable its Class.PartOperation.UsePartColor|UsePartColor property to change the entire intersection to a specific color.

To intersect overlapping parts together:

1. Select all parts to intersect.

2. Click the Intersect button. All of the parts combine into one solid Class.IntersectOperation with the name Intersection.

   

Negating Parts

The Negate tool negates a part so that when it's unioned with another part, the shape of the negated part is subtracted from the other part.

To subtract a part from other overlapping parts:

1. Select the part you would like to negate from other parts.

2. Click Negate. The part becomes a Class.NegateOperation with the name NegativePart and turns pink and translucent to indicate its state.

   

3. Select both the negated part and the parts you want to subtract it from.

4. Click Union. The negated part is cut out from the included overlapping parts.

   

Separating Unions or Intersections

The Separate tool separates a Class.UnionOperation back into its individual parts, essentially serving as an "undo" tool for unions and intersections.

To separate a union or intersection back into individual parts:

1. Select a Class.UnionOperation.

2. Click Separate. The parts separate back into their original form.

   

Render Fidelity

By default, new solid modeled operations will always be shown in Enum.RenderFidelity.Automatic|Automatic render fidelity, meaning the part's detail is based on its distance from the camera as outlined in the following table.

Distance From Camera	Render Fidelity
Less than 250 studs	Highest
250-500 studs	Medium
500 or more studs	Lowest

Smoothing Angle

A solid modeled part's Class.PartOperation.SmoothingAngle|SmoothingAngle property smooths angles between adjacent surfaces of the same color or material. A higher value produces a smoother appearance while a lower value produces a rougher appearance with more sharp edges.

While a value between 30 and 70 degrees usually produces a good result, values between 90 and 180 are not recommended as they may cause a "shadowing" effect on unions and intersections with sharp edges.

`Class.PartOperation.SmoothingAngle|SmoothingAngle` = 0

`Class.PartOperation.SmoothingAngle|SmoothingAngle` = 50

In-Experience Solid Modeling

In addition to the Union, Intersect, and Negate tools in Studio, you can allow players to use solid modeling operations while inside an experience through Class.BasePart:UnionAsync()|UnionAsync(), Class.BasePart:IntersectAsync()|IntersectAsync(), and Class.BasePart:SubtractAsync()|SubtractAsync(). All of these methods must be called on a Class.BasePart and they all require an array of one or more parts to union with, intersect with, or subtract from the calling part.

In-experience solid modeling operations are asynchronous, meaning they can impact performance. For best results, you should not perform a large series of `Class.BasePart:UnionAsync()|UnionAsync()`, `Class.BasePart:IntersectAsync()|IntersectAsync()`, or `Class.BasePart:SubtractAsync()|SubtractAsync()` calls in quick succession. When performing a `Class.BasePart:UnionAsync()|UnionAsync()`, `Class.BasePart:IntersectAsync()|IntersectAsync()`, or `Class.BasePart:SubtractAsync()|SubtractAsync()` operation, the following properties from the calling part are applied to the resulting union: `Class.BasePart.Color|Color`, `Class.BasePart.Material|Material`, `Class.BasePart.MaterialVariant|MaterialVariant`, `Class.BasePart.Reflectance|Reflectance`, `Class.BasePart.Transparency|Transparency`, `Class.BasePart.Anchored|Anchored`, `Class.BasePart.CanCollide|CanCollide`, `Class.BasePart.Density|Density`, `Class.BasePart.Elasticity|Elasticity`, `Class.BasePart.ElasticityWeight|ElasticityWeight`, `Class.BasePart.Friction|Friction`, and `Class.BasePart.FrictionWeight|FrictionWeight`.

UnionAsync()

To demonstrate Class.BasePart:UnionAsync()|UnionAsync(), the following Class.Script uses the Part1 Class.BasePart from the workspace, unions it together with the Part2, Part3, and Part4 Class.BasePart|BaseParts, then parents the resulting Class.UnionOperation to the workspace at the original position of Part1.

local mainPart = workspace.Part1
local otherParts = {workspace.Part2, workspace.Part3, workspace.Part4}

-- Perform union operation
local success, newUnion = pcall(function()
	return mainPart:UnionAsync(otherParts)
end)

-- If operation succeeds, position it at the same location and parent it to the workspace
if success and newUnion then
	newUnion.Position = mainPart.Position
	newUnion.Parent = workspace
end

-- Destroy original parts which remain intact after operation
mainPart:Destroy()
for _, part in otherParts do
	part:Destroy()
end

IntersectAsync()

To demonstrate Class.BasePart:IntersectAsync()|IntersectAsync(), the following Class.Script uses the Part1 Class.BasePart from the workspace, intersects it with the Part2 and Part3 Class.BasePart|BaseParts, then parents the resulting Class.IntersectOperation to the workspace at the original position of Part1.

local mainPart = workspace.Part1
local otherParts = {workspace.Part2, workspace.Part3}

-- Perform intersect operation
local success, newIntersect = pcall(function()
	return mainPart:IntersectAsync(otherParts)
end)

-- If operation succeeds, position it at the same location and parent it to the workspace
if success and newIntersect then
	newIntersect.Position = mainPart.Position
	newIntersect.Parent = workspace
end

-- Destroy original parts which remain intact after operation
mainPart:Destroy()
for _, part in otherParts do
	part:Destroy()
end

SubtractAsync()

To demonstrate Class.BasePart:SubtractAsync()|SubtractAsync(), the following Class.Script uses the Part1 Class.BasePart from the workspace, negates the Part2, Part3, and Part4 Class.BasePart|BaseParts from it, then parents the resulting Class.UnionOperation to the workspace at the original position of Part1.

local mainPart = workspace.Part1
local otherParts = {workspace.Part2, workspace.Part3, workspace.Part4}

-- Perform subtract operation
local success, newSubtract = pcall(function()
	return mainPart:SubtractAsync(otherParts)
end)

-- If operation succeeds, position it at the same location and parent it to the workspace
if success and newSubtract then
	newSubtract.Position = mainPart.Position
	newSubtract.Parent = workspace
end

-- Destroy original parts which remain intact after operation
mainPart:Destroy()
for _, part in otherParts do
	part:Destroy()
end