Brush Tools Clip

With the Clip tool, you can remove chunks of a brush by clipping it against a plane, or alternatively split a brush into two along the defined plane. You do this by drawing a clip plane, where everything on one side of the plane is deleted or split from the original brush.

Selecting a Brush

Selecting a brush with the Clip tool is the same as in Resize mode.

Drawing the Clip Plane

When you have a brush selected, a red handle will appear near your mouse cursor, but unlike your cursor the handle will be snapped to the grid. This red handle is the start point of the clip plane. By clicking and dragging, a green handle and a blue handle will appear. The green dot is the end point for the clip plane.

Drawing a clip plane, flipping it, and then clipping the brush

In a 3D perspective, the part of the brush that is visible through the clip plane’s green side will be saved after clipping. The part of the brush that is visible through the clip plane’s red side will be deleted. From an isometric, axis aligned camera perspective, the clip plane will look like a red line next to a green line. As with a 3D view, the part of the brush that is on the green side of the line will remain, while the part on the red side will be destroyed.

The clip plane and handles

You can adjust the clip plane by clicking the red, blue, or green handles, and moving them. By default, the blue handle will appear alongside the red handle, but once you have drawn the clip plane, you can move it or the red dot to make more complicated cuts with the plane.

Clipping, Splitting, and Flipping

Once you have drawn the clip plane, you can click the Clip, Split, or Flip Plane buttons beneath the SabreCSG tool selection bar. The Clip button performs the clip you have drawn, deleting one side of the brush. If clipping would remove the wrong side of the brush, you can click Flip to reverse which side the clip will remove.Additionally you can press R to flip the plane or press Return to apply the clip. You can also click Split, which will create a new brush from the clipped part, effectively splitting the brush in two. This allows you to manually modify or delete parts that were previously a whole brush, which can be especially useful for creating concave geometry.

Splitting a brush from a 2D perspective

Some clips will decrease the number of faces and vertices that a brush has, while other clips will increase it. For example, clipping can let you quickly bevel a corner, create a hexagonal prism from a cuboid, or create a triangular prism for a ramp.

Splitting a brush in two

Since clipping a brush usually requires adjusting the camera position and drawing the clip plane, it is often best to create some geometry that you can then quickly select and duplicate throughout the level. For example, if your level will have ramps, it is best to create one archetype ramp, place it off to the side in the world or in its own group in the hierarchy, and duplicate it throughout the level.

Drawing the clip plane from a 2D perspective

It is also sometimes best to draw the clip plane from an isometric, axis aligned camera, where it is easier to see the grid and judge exactly where where the clip will occur. Switching between camera modes and perspectives can take time, however, so it may help to have a second Scene view open as a dedicated 2D view of your level.

Precision

You can select the individual points by clicking on them once. This is useful for clipping corners. By holding the V key you can use vertex snapping to precisely align clip planes.

Clipping corners by moving the blue point