Working with Brushes

From FleshWorks

Author: scumble

Contents 1 Important points 2 Building basic primitives 2.1 Making a Cube 2.2 Manipulating the Builder Brush 3 Moving 4 Vertex Editing - reshaping 5 Brush Operations 5.1 Adding and Subtracting 5.2 Note: Alignment 5.3 Intersection and Deintersection 5.4 Brush Clipping 6 Pitfalls and Tips

Important points

• Always make sure grid snapping (Snap to Grid) is turned on
• Do not try to make complex geometry with BSP. Detail is always added using static meshes.

Building basic primitives

On the left of the T3ed interface, you will see the set of tools shown on the right.

With these, you can create cubes, stairs, cylinders, cones, sheets, tetrahedrons (spheres) and volumes. Not all of these have much use in the editor, as they are pretty much "left over" from the Unreal Engine.

Making a Cube

Cubes are the simplest. Click on the cube button and you will see a red builder brush appear in all of the viewports. Note that the builder brush can be hidden by pressing "B", so if you ever wonder where the builder brush has gone, remember to press "B" in case it has been hidden.

The brush created will have the default dimensions, but this is easily changed by right-clicking on the brush primitive tool. For the cube you get the following dialog:

You simply alter the parameters and click Build. The meaning of the parameters are as follows:

Height

Width

Breadth

Wall Thickness

if you make a hollow cube, this will be the thickness of the wall.

Hollow

if this is set to true, you will get a hollow cube with a wall thickness specified by the preceding parameter

Tessellated

setting this to true will force the cube to be constructed from triangles (could be useful for later vertex editing)

Units

choose Unreal units or feet. Best to use Unreal units.

Manipulating the Builder Brush

Moving

Once you've got a simple brush, you'll probably want to move it into the position you want. While in camera movement mode , holding down shift and dragging the builder brush will move it while scrolling the viewport, and holding down ctrl will move the brush leaving the viewport static.

Moving brushes in the 2D views is simpler than in the 3D view. In the 3D view, dragging with the left mouse button moves the brush in the y-axis, dragging with the right moves in the x-axis, and dragging with both mouse buttons moves in the z-axis (up and down).

For precise work, it makes sense to use the 2D views as much as possible, given that it is difficult to judge the grid reliably in the 3D view.

Vertex Editing - reshaping

Now, changing the shape of the brush can be done by using the scaling tool, but this is not the best method. Scaling rarely gives you the kind of control you require, and there is a risk of coming off the grid, which is a Very Bad Thing^TM that can lead to misery later on. The best course of action is to use Vertex Editing, as recommended by Krypt - one of the level designers at Ion Storm. This is actually the most flexible way of getting the results you want.

To get into vertex editing mode you select the tool. In the 3D view, you can only select vertices individually by clicking on them, but you can move them in any viewport by shift or ctrl-dragging, similar to moving brushes around.

In the 2D viewports, you can ctrl-alt-drag to use box selection for selecting multiple vertices.

See here and here for alternative tutorials on vertex editing.

Brush Operations

Adding and Subtracting

Once you have used the preceding methods to get your builder brush into the right shape, and in the right place, you can subtract it from or add it to the game world.

This involves little more than clicking the add or subtract button. If the operation causes a crash, you may have a problematic graphics card - consult GraphicsCardIssues for help with this.

Once you have subtracted a brush, hide the builder brush by pressing "B", and you should see a yellow wireframe brush. For added brushes the wireframe will appear blue. It is now possible to manipulate these brushes in the same way you would the builder brush.

Note: Alignment

You must make sure that adjacent bruses are always lined up correctly. Don't overlap them, as it is likely to cause trouble later on and it is also bad practice in any case. There is absolutely no reason to do this, ever.

According to documentation at UDN, you should intersect a brush before subtracting it, and deintersect before adding. This ensures that there is no overlapping.

Intersection and Deintersection

At this point, things get a little more complicated.

Intersection is very useful when you want one subtracted brush to fit snugly next to another one (or several). You will overlap the builder brush with the subtracted brush as you want it in this case. When you click the Intersect button, the parts of the builder brush inside any subtracted brush will be chopped off, leaving you with a perfect fit - then you can subtract.

Brush Clipping

A useful UDN document can be found here, explaining how to clip and split brushes clearly, and also offering some advanced tips.

Bear in mind that it's a good idea to save your work before attempting brush clipping as it often crashes the editor.

Pitfalls and Tips

• If you've managed to come off the grid , don't panic. Simply reset the builder brush to the origin.
• You can quickly duplicate brushes by pressing Ctrl+W - this can be quicker than getting the builder brush into the right shape, as you can start from a brush similar to what you want.
• You can also check here [1] for solutions to most BSP problems, simple or complex: