Modeling Mode Overview

The Modeling editor mode, refered to as Modeling Mode, provides a toolset for creating, sculpting, and editing meshes directly in Unreal Engine. You can use it to create new meshes, rapidly prototype level geometry, and edit existing models to add variety to your world. This overview outlines the core concepts behind these tools and their workflow, how to access them, and the basics of working with them.

Accessing Modeling Mode

To use Modeling Mode, click the Select Mode dropdown, then select Modeling. Alternatively, press SHIFT+5 to immediately switch to this mode.

Once selected, 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.

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 you are working on various types of actors in Unreal Engine (UE), for example, a static mesh, dynamic mesh, or a volume. These are collectively referred to as "a mesh" 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 (polygon with more than 4 sides) into triangles at runtime.

In the Modeling Mode, you can edit the triangles of your model using the Triangle Edit tool. This is one of the most low-level 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 using the tools in the Model category.

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 use the Tri Select (Triangle Selection), Generate PolyGroups , and Paint PolyGroups tools to assign PolyGroups.

You can then use PolyGroups for traditional box modeling using the PolyGroup Edit tool and to create UV islands using the UV tools.

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

Tools, Undo History, and Accepting Changes

Most tools in Modeling Mode will 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, the changes are discarded, and the mesh will revert to what it looked like before you started editing it. When you press Accept, you exit the tool, and all the 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 you can generally undo or redo individual changes inside a particular tool, once you accept the changes, the Undo system only tracks the state of the mesh before and after the tool is active. For example, you can undo each brush stroke while using the Vertex Sculpt tool. Once you click Accept, exiting the sculpt tool, you can only Undo the combined result of all the brush strokes — reverting your mesh to its state before you started 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. Using Project Settings, you can configure the creation and selection of meshes, as well as 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, click any of the predefined primitive shapes in the Create category and move your mouse cursor into the Viewport. A template of the shape you selected follows your cursor and snaps to the level grid. Click where you want to add the mesh in your game's world and the editor will create the shape with the parameters you configured in the Tool Properties panel.

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

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, then click a mesh, you can choose its components and perform 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.

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, disable Combined Gizmo using the settings icon in Modeling Mode Quick Settings.

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 hotkeys listed in the table depending on the tool and operation. 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:

1. Select the gear 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 becomes available with tools for editing your mesh selections.

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.