Modeling Mode Overview

The Modeling editor mode, also known as Modeling Mode, provides a toolset for creating, sculpting, and editing 3D geometry directly in Unreal Engine (UE). These tools offer workflows for topology edits, UV creation, multiple material assignments, collision editing, and texture baking.

This overview outlines:

• How to access the mode and its tools
• The core concepts behind the tools and their workflow
• The basics of working with the tools

Before using Modeling Mode, we recommend understanding the following topics:

• Asset
• Actor
• Component
• Level Editor

Accessing Modeling Mode

To access Modeling Mode, click the Select Mode dropdown and then click Modeling. Alternatively, press SHIFT+5 to switch to this mode immediately. To learn more about the various modes, see Level Editor Mode.

If Modeling does not appear in the mode dropdown, ensure the editor is enabled in your Plugins.

Edit > Plugins > Modeling Tools Editor Mode

To learn more, see Working with Plugins.

When you click the mode, Modeling Mode's user interface (UI) appears with multiple panels to help streamline your workflow.

Help Line

An additional panel with tooltips, such as hotkey commands, is available in the Bottom Toolbar of the Level Editor when using Modeling Mode.

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Understanding Key Concepts

Although many tools in Modeling Mode are similar to their counterparts in other modeling software, there are a few essential differences in how Modeling Mode structures mesh editing that you should know before you begin working with it.

Terminology

The modeling tools are usable when working on various types of Unreal Engine (UE) actors, such as static meshes, dynamic meshes, or volumes. These are collectively referred to as "meshes" or "meshes", except when a tool is only usable for a specific actor type.

Triangles and PolyGroups

Unreal Engine renders all models as triangulated meshes. In other words, when you import or create a mesh, its surface is automatically broken up into triangles (tris) regardless of whether they were already defined in a different environment. This conversion to triangles provides several guarantees:

• UE can't import or create a model that it can't render.
• UE's rendering is portable across all platforms, as all graphics drivers universally recognize triangles.
• UE does not need to spend time and resources resolving quadrilateral (quad) polygons and n-gons (polygons with more than 4 sides) into triangles at runtime.

In Modeling Mode, you can edit the triangles of your mesh using the Triangle Edit tool. This tool is one of the most low-level topology editing tools, based entirely on direct selection and editing of tris and vertices. Although Unreal Engine does not natively recognize quads or n-gons, it does support PolyGroups, which can mimic those features. PolyGroups are arbitrary collections of triangles that various tools in Modeling Mode can define. You can then manipulate these groupings for traditional box modeling with the PolyGroup Edit tool, create UVs with the UV tools, and more.

When creating a mesh using one of the primitive shapes in the Create category, you can configure the PolyGroups of your new mesh using the PolyGroup Mode setting.

Additionally, you can assign PolyGroups with the following tools:

• Tri Select (Triangle Selection)
• Generate PolyGroups
• Paint PolyGroups

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To learn more about creating and using PolyGroups, see Understanding PolyGroups.

Tools, Undo History, and Accepting Changes

Most tools in Modeling Mode do not apply changes to meshes immediately. Instead, the tool previews the mesh with your changes in place, and the Tool Confirmation panel displays a Cancel and Accept button.

If you exit Modeling Mode or press Cancel, your changes are discarded, and the mesh reverts to what it looked like before you started editing it. When you press Accept, you exit the tool, and all changes you made to the mesh while using the tool are applied to the underlying mesh. Changes are also applied when you switch from an active tool session to another tool.

While using a tool, you can undo or redo individual changes. However, once you accept the changes, UE's undo history system only tracks the state of the mesh before and after the tool is active. For example, you can undo each brush stroke within the Vertex Sculpt tool. Once you click Accept, exiting the sculpt tool, you can only undo the combined result of all the brush strokes. Undo reverts your mesh to its state before you start the tool.

Meshes, Assets, and Project Settings

The type of actor you choose to represent your mesh determines how Modeling Mode handles the creation and editing process. When creating a new mesh using the Create category, you use Output Type to select the desired actor. You can choose between the following actors as your target mesh:

• Static Mesh: Represents your model and is saved in the Content Browser. An instance of the mesh is placed in the level.
• Dynamic Mesh: Represents your model and is saved in the level only.
• Volume: Represents an area that triggers a behavior and is saved in the level only.

These types have various use cases and benefits. You can change the actor type of the current mesh using tools such as Convert and Transfer. Use the Project Settings to configure the creation and selection of meshes and the saving of assets.

To continue learning about how output types are handled and how to adjust settings for your workflow, see the Working with Meshes documentation.

Using Modeling Mode

Creating a Mesh

To create a new mesh, follow these steps:

1. Open the Create category.
2. Click any predefined primitive shape and move your mouse cursor into the Viewport. A template of the shape follows your cursor and snaps to the level grid.
3. Click where you want to add the mesh in your level.

The editor creates the shape using the parameters you configured in the Tool Properties panel.

You can also create custom meshes using tools in the Create category. For example, you can use the Extrude Polygon tool to draw an outline for a mesh and then extrude it to create a 3D shape.

Several tools, such as Extrude Polygon and Extrude Path, use a grid to draw shapes. To control the position of the grid, Ctrl + Click your desired location.

Editing a Mesh

Most of the other tools in Modeling Mode are built around editing an existing mesh in your game's world. For example, if you select Triangle Edit or PolyGroup Edit and then click a mesh, you can perform topological modeling operations.

Individual operations in the Triangle Edit and PolyGroup Edit tools, such as Extrude, Push Pull, or Cut Faces, appear in the Tool Properties panel. After you make your edits, click the Accept button to finalize your changes or click Cancel to discard them.

You can select any mesh in your world and edit it using these tools, including meshes that were not created in Modeling Mode. For example, you can use the Lattice tool on a high-resolution mesh to quickly reshape it.

If you plan to edit a high-resolution model, we highly recommend duplicating the asset using the Duplicate tool to preserve the original mesh.

Gizmo

Modeling Mode has a dedicated gizmo for unique and quick mesh transformations. By default, scale, rotate, and translate (move) are combined into one gizmo.

To use an individual modeling gizmo consistent with the Level Editor's standard translation, rotation, and scale, follow these steps:

1. Click the settings icon in Modeling Mode Quick Settings.
2. Disable Combined Gizmo.

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In addition to the modeling gizmo's structure, you can:

• Switch between relative and absolute grid snapping by toggling World Grid Snapping.
• Use the Transform Panel for numerical input for world space and local delta values.

The Transform Panel shows directly in the Viewport and is available for several modeling and UV tools.

Gizmo Hotkeys

You can use the gizmo hotkeys listed in the table for certain tools. Specific modeling tools have additional gizmo attributes, such as a repositionable grid for Extrude Polygon, Extrude Path, and the Patten tool. Use the Help Line to indicate when you can use these hotkeys.

Mesh Element Selection

Modeling Mode provides the option for direct mesh element selection for a more consistent and optimized workflow. The Mesh Element Selection lets artists select a mesh, select the element, and then invoke an operation without using an intermediate tool such as PolyGroup Edit or Triangle Edit.

To enable the tool, follow these steps:

1. Click the settings icon in Modeling Mode Quick Settings.
2. Select Mesh Element Selection.
3. Exit and re-enter Modeling Mode.

Additionally, when the setting is enabled, a Select category with tools for editing mesh selections becomes available.

Custom Tool Presets

As you use the various tools in Modeling Mode, you may establish workflows that involve repetitive settings for specific tools. Instead of repeatedly entering these settings, you can use the Presets option when selecting a tool. With custom presets, you can save current tool settings, reload these settings in the future, and manage which collections of presets are active and enabled for a project or user.

Tool Categories

To learn more about these categories and their specific tools, see Modeling Tools.