Hazel Whorley
2D Art / Level Design

me@hazelwhorley.com

tutorials

Geometry Tools [UE3]

This tutorial explains how to use the geometry tools in UE3 to clip, extrude and vertex edit BSP brushes. These tools were directly accessible on the toolbar in the previous editor, and have now been moved to the geometry tools window.

At least very basic knowledge of UnrealEd is assumed; how to move around, add and move objects, and add / subtract BSP brushes.



Geometry Mode

Camera mode icon Geometry mode icon

Click the cube icon on the left toolbar to open the Geometry Tools window. Click the camera icon at any time to return to camera mode.


Geometry Tools Window

From left to right:

- Toggles on and off the geometry modifiers window (shown below)
- Object selection mode
- Poly / face selection mode
- Edge selection mode
- Vertex selection mode

Other options:

Show Normals - Displays small red lines on the brush to indicate which side of a poly is visible.

Affect Widget Only - Only move the widget and pivot around, movement doesn't affect the shape.

Soft Selection - Selects vertices within a specified radius, and moves them depending on how far from the origin they are. Not recommended for working with BSP.


Geometry Modifiers Window

The modifiers window displays more options for each selection mode.

Edit - Simple edit for each selection mode (enabled by default).

Clip - For clipping (removing an area from) a brush. Object selection mode must be enabled.

Extrude - Extrude from a selected face. Only available in poly selection mode.


I don't recommend using the buttons in the lower half of the window. They can be used to make more complex brushes, but you're more likely to run into BSP errors by using them. It's better to use multiple simple brushes or static meshes. There's no harm in experimenting with them though :)



Vertex Editing

With vertex selection enabled, in one of the 2d viewports click a vertex or hold Right Alt and click and drag to select multiple vertices. Move the vertices the same way you would move any other object in UnrealEd. Hold down Ctrl and click and drag to move the vertices, or use the move widget.



Clip Tool

  1. Toggle the modifier window on
  2. Switch to object selection mode
  3. In the modifier window, select the Clip option
  4. Ctrl + Right-Click in one of the 2d viewports to place clipping markers



  5. Move the markers if necessary. The object will be clipped on the side where the red line points. To reverse which side gets clipped, check bFlipNormal in the modifiers window.
  6. Select the object to clip



  7. Press Apply in the modifiers window



Extrude Tool

The extrude tool adds extra sections to a brush. It's important to keep brushes simple and convex to avoid BSP errors. Anything more complex than making a brush with a beveled part on one side (as shown in this example), or a cube with 45 squared off corners should be done with several simpler brushes.

  1. Toggle the modifier window on (if it isn't already)
  2. Enable poly selection mode
  3. Select the face you wish to extrude from



  4. Click Extrude in the modifier window
  5. Enter the length and number of segments of the extruded area



  6. Click Apply
  7. Vertex edit the brush if needed