Mesh Tool User Guide

1.0.3
marynate

Start the Mesh Tool

Edit Mode Toolbar

Mesh Toolbar

Mesh Tool Hotkeys

Select

Select Mesh/Elements by Mouse Click

Select Mesh by Mouse

Select Edge by Mouse

Select Vertex by Mouse

Click Threshold

Marquee Select

Additive Mode:

Subtract Mode:

Ignore back faces and occluded faces

Select All/None/Inverse

Transform

Object Operations

Flip All

Weld All

Recompute Normal

Hide Others / Show All

Insert Primitives

Auto UV

Auto UV Scope

Skip Generate Distance Fields

Display Proxy Mesh

Vertex Operations

Edge Operations

Face Operations

Display Options

Known Issues:

Tutorial: Microwave Oven

Tutorial: [TBD]

Mesh Tool is a mesh editor for Unreal Engine. It allows you to edit mesh assets and prototype props and levels without leaving Unreal Editor.

Start the Mesh Tool

To use the Mesh Tool, click the Mesh Tool icon on the editor mode tab.

Mesh Tool UI (No Mesh Selected)

Mesh Tool UI (Has Read-only Mesh Selected)

Mesh Tool UI (Has Mesh Selected)

Edit Mode Toolbar

Use Edit Mode Toolbar to switch between Vertex/Edge/Face/Object edit mode.

 Vertex Mode. Edit mesh in Vertex view.

 Edge Mode. Edit mesh in Edge view.

 Face Mode. Edit mesh in Triangle view.

 Object Mode. You can select other mesh to edit only in Object Mode.

Mesh Toolbar

Selected mesh name will be displayed on Mesh Toolbar, you can also duplicate or browse to selected mesh.

 Duplicated selected mesh, and start editing duplicated mesh.

The mesh will be duplicated into the same folder of the original mesh. But if the mesh to be duplicated is an Engine Asset, then it’ll be duplicated into current Project’s Content folder (And if there is a “Meshes” folder, it’ll be put into that folder automatically) if the .option is set to on.

 Duplicated selected mesh, and continue editing original mesh

 Browse to selected mesh in Content Browser

If the selected mesh is an Engine Asset, the mesh name will be displayed in gray, to indicate it’s read-only. You can use  button to duplicate it to project content folder to make it modifiable.

Mesh Tool Hotkeys

TL;DR

Some useful hotkeys you might want to know first:

C - select coplanar faces in face mode; select connected parallel edges in edge mode

V - vertex snap while transforming elements

B - bridge edges

Shift - extrude faces/edges

Caps Lock - show/hide widget

Insert - edit transform pivot

You can customize default hotkeys in Editor Preferences - Keyboard Shortcuts - Mesh Tool Edit Mode:

Select

Select Mesh/Elements by Mouse Click

Select Mesh by Mouse

You can only change mesh selection in Object mode. Mouse click a mesh to select it.

Click on a face to select the face.

Select Edge by Mouse

Click on a edge to select the edge.

In Unreal Engine, each face has it’s own 3 edges. There are technically 2 edges between adjacent faces.

You can set Local Transform Coord option in Transform Panel to “Auto”, then set the gizmo coordination system to “Local” to verify that:

Clicked on edge on right face, noticed that the “Right”/Y arrow is pointing downward

Clicked on edge on left face, noticed that the “Right”/Y arrow is pointing upward

In Mesh Tool, most edge related mesh operation will treat 2 shared edge as one single edge, so you don’t have to care which edge of the two is actually selected.

Select Vertex by Mouse

Click on face near the vertex to select vertex.

Mesh Tool is using ray tracing on faces to detect which vertex will be selected, so to select the vertex successfully, the mouse cursor should be over the mesh when clicking.

Mouse cursor is not over mesh, no vertex will be selected after click.

When mouse cursor is over mesh, you will notice the cursor shape has changed.

Left click will select the vertex.

Click Threshold

Vertex/Edge selection is based on ray tracing, the Vertex/Edge Click Threshold controls how far between a ray and a vertex/edge will be considered as selected.

Increase the threshold if you are working on a large mesh and finding selecting elements is requiring too much precise clicking.

Marquee Select

Press Ctrl and Alt key altogether and dragging mouse to marquee select

Additive Mode:

Press Ctrl + Alt + Shift key altogether and dragging mouse to add elements into existing selection

Subtract Mode:

Press Ctrl + Alt to start marquee select, then let go of Alt key to remove elements from existing selection

Ignore back faces and occluded faces

Use Ignore Backfaces and Ignore Occluded and Backfaces option in Select panel to control whether back faces/occluded faces will be selected.

When both options are off, all faces within marquee box will be selected.

With Ignore Backfaces option on, all backfaces will be ignored

With Ignore Occluded and Backfaces option on, only non-occluded faces will be selected

Select All/None/Inverse

Select all mesh elements

Deselect all mesh elements in element editing mode (vertex/edge/face), deselect mesh when in object editing mode.

Select all non-selected mesh elements

Transform

Object Operations

Flip All

Press “Flip All” button to flip all faces normal of selected mesh.

Before:

After:

Weld All

Press “Weld All” button weld vertices within weld threshold into one vertex. (Weld threshold is defined in Vertex panel)

Inspect Status Panel under bottom of Mesh Tool, there’re total 74 vertices for this mesh.

After pressed “Weld All”, there’s no visual change on the mesh, but inspecting the Status Panel, you’ll notice there are now 64 vertices. That was 10 vertices been welded.

Recompute Normal

Pres “Recompute Normal” to recompute mesh normals base on faces’ smoothing group assignment.

Before:

After:

Hide Others / Show All

Hide Others / Show All operation is useful when you want to isolate one specific mesh for edting without distraction from other actors in scene.

Select mesh you want to isolate, press  button to show only selected mesh. All actors other than selected will be hidden in editor except light actors.

Press  button to show all hidden actors.

Insert Primitives

Press “Insert primitives” to insert primitive mesh into current mesh. If “Replace Mesh” option is checed, then current mesh will be replaced with the primitive selected.

Quad

Cube

Hollow Cube

Cylinder

Sphere

Cone

Auto UV

Check “Auto UV” on to auto generate UV after each mesh operation. You can specify the projection method used for auto uv generation, and check on “Override Scale” to use different Texture Map scale other than default texture map scale (defined in Texture Map panel)

A mesh to be edited.

Mesh edited with “Auto UV” off. Since there’s no new UV be generated, the texture is stretched.

Mesh edited with “Auto UV” on. As new UV been generated, the texture on mesh will remain same scale.

Auto UV Scope

Use Auto UV Scope option to fine tune the scope of Auto UV.

Modified Only : Only apply Auto UV to modified part

Linked: Apply Auto UV to all linked elements

All: Apply Auto UV to entire mesh

Skip Generate Distance Fields

Checking this option on will prevent mesh Distance Fields data been generated while editing mesh:

Checking this option off, any editing operation will trigger Distance Fields data re-generation:

Be aware that it did not prevent Distance Fields data generation if the mesh been modified outside of Mesh Tool. (e.g. changing static mesh setting in Static Mesh Editor)

User need to enable mesh distance fields generation explicitly afterward to keep distance fields up-to-date.

Display Proxy Mesh

As of version 1.0.2, Proxy Mesh display is an experimental feature, which need to be enabled in Editor Preferences - Content Editors - Mesh Tool:

Here’s normal mesh display.

Here’s mesh display when “Display Proxy Mesh” option is on.

The Proxy Mesh represents the mesh that Mesh Tool is actually working on all the time, all mesh operation will then be synced/built into the static mesh asset behind the scene. The purpose of displaying proxy mesh is by combining with “Show/Hide Selected Elements” option in Select panel to selectively display part of the proxy mesh.

Vertex Operations

Edge Operations

Face Operations

Display Options

Known Issues:

• Build Mesh Message pop up for every mesh operation
• Align Texture Map operation not Undoable
• Hotkeys sometimes only works when level editor viewport has the focus (e.g. after left or right mouse click in the viewport)
• Hotkeys are not customizable yet

Tutorial: Microwave Oven

Drag a Cube into level editor viewport.

Click “Duplicate” button on Mesh Toolbar.

Rename the duplicated mesh to “SM_MicrowaveOven” in Content Browser.

Notice that the name changed on Mesh Toolbar.

Click the Cube in level editor viewport to select it.

Switch to Face edit mode, click on side face to select it.

Click “Coplanar Faces” in “Select” section to select side faces.

Use Transform Widget to move selected faces.

Hold Shift and mouse click to select front faces.

Click "Duplicate in "Face” section to duplicate selected faces.

Click "Edit Custom Transform Pivot”.

Hold "V” key and dragging Transform Widget to snap transform pivot to left side of selected faces.

Use Rotate Widget to rotate selected faces.

Click the “Reset” icon to reset Transform Pivot to default.

Make sure the rotated faces still selected.

Hold Shift and Alt key and drag Transform widget to extrude selected faces

Click “Flip All” in “Object” section to flip all faces normal. Select the faces of the back of the lid.

Click “Flip” in “Face” section to flip selected faces’ normal.

Click “Flip All” again to flip all faces’ normal back.

Switch to “Edge” edit mode to fine tune edges.

Select front side faces, click “Inset” to inset selected faces. Use Scale widget to shape selected faces.

Hold “Shfit” + mouse drag to extrude selected faces inward.

Select right side faces.

Click “Inset” and use Scale widget to shape panel area.

Select upside edge, hold “V” and drag Transform Widget to line upside edge with the vertex of extruded faces.

Select a material in Content Browser, click “Assign Material” in “Face” section to assign Panel material.

Select any face in the Lid, click “Linked” in “Select” section to select all faces of “Lid”.

Select a translucent material and click “Assign Material to assign Lid material.

Select any face in the Base, and click “By Material” to select all faces of other than Panel and Lid

Assign Base material.

Done! And don’t forget to “Save” the “SM_MicrowaveOven” asset in Content Browser.

Tutorial: [TBD]

[WIP]