Editable Meshes¶

Every mesh you edit with the Modelling tools has an Editable Mesh component. It stores the mesh as faces you can edit (quads and polygons, not only triangles) and rebuilds the Unity mesh whenever you change it.

Getting an Editable Mesh¶

There are three ways:

• Create a primitive from the Modelling Create tab, or from GameObject > World Toolkit > Modelling. See Primitives.
• Convert an existing mesh. Right-click the Mesh Filter component of any object and choose Convert to WTK Mesh, or select the object and click Convert to WTK Mesh at the top of the Topology tab. With a primitive or a Boolean Stack selected, the same button reads Make Editable.
• Add the component manually: Add Component > World Toolkit > Modelling > Editable Mesh.

The inspector¶

Source Asset

The .emesh asset that holds the mesh data, when it's stored outside the scene. Empty when the data is stored in the component. See Mesh data and .emesh files.

Meshes made by a generator (a primitive, a Boolean Stack or a decal) say so in the inspector: This mesh is controlled by its generator. Use Make Editable to edit its topology.

Shading¶

Auto Smooth

Smooths the shading across edges whose faces meet at an angle up to Auto Smooth Angle, and keeps sharper edges hard. Edges you marked hard stay hard either way (see Normals and shading).

Auto Smooth Angle

The angle limit, from 0 to 180 degrees. 30 by default.

UV options¶

Auto UV

Generates UVs automatically from the mesh geometry.

Auto UV Mode

Use local-space or world-space coordinates for the automatic UVs. World space keeps texture scale consistent across objects of different sizes.

Auto Bake Lightmap UVs

Generates lightmap UVs (UV1) automatically.

See UVs for manual UV editing.

Editable Primitives¶

Primitives keep their parameters in an Editable Primitive component, next to the Editable Mesh. Its inspector shows the parameters of the primitive's Kind: sizes, segments, the vertex color, the UV offset, scale and rotation, and the spline settings of stairs, tubes and surfaces. Changing a value rebuilds the mesh right away. Right-click the component and choose Force Rebake to rebuild it from its parameters on demand.

While a mesh is controlled by its primitive, its vertices, edges and faces can't be edited directly. Click Make Editable at the top of the Topology tab to turn it into a regular Editable Mesh and edit the topology. After that, the primitive parameters are gone.

Combining and splitting objects¶

In the Topology tab, under Modify:

• Merge Meshes merges the selected Editable Mesh objects into the active one.
• Separate moves the selected faces into a new Editable Mesh object.

Mesh data and .emesh files¶

An Editable Mesh stores its data in the component, inside the scene, unless it has a Source Asset: an .emesh file in the project. Right-click the Editable Mesh component for the options:

Export Mesh... / Import Mesh...

Save the editable topology to a file, or load it back.

Export to .OBJ...

Save the mesh as a Wavefront .obj file for other 3D applications. Faces stay as you modelled them: quads and polygons aren't triangulated and neighbouring faces keep sharing their vertices, with the UVs and normals of each face corner and one material group per material slot. Hidden faces are exported too, and loose edges are kept as lines. Only faces with holes are written as triangles, because the format has no holes. The file is in the object's local space, and no .mtl file is written.

Externalize To .emesh...

Store the mesh data in a separate .emesh asset instead of inside the scene. Useful for large meshes, or to reuse the same mesh in several places.

Embed Data Into Component

The opposite: move the data from the .emesh asset back into the component.

To create an object from an .emesh asset, right-click the asset in the Project window and choose Create EditableMesh From .emesh.

To move the data of every mesh in a scene out of the scene file automatically, see Scene Meshes in the Modelling settings.

Prefabs¶

When you create a prefab asset from objects whose Editable Meshes store their data in the component, World Toolkit moves each mesh's data into an .emesh file in a <PrefabName>_EMeshes folder next to the prefab, and links the mesh to it. This runs as a background task, with its progress in Unity's status bar.