Creates a Negative Extrusion (NXTR) by positioning PAVE elements to form a Loop (LOOP) and then extruding them. A negative extrusion represents a negative volume, that is, a hole.

The display of the negative extrusion volume in the 3D view can be modified. Refer to Component Visibility, Drawing Level and Obstruction for further information.

To achieve the correct justification and orientation for the negative extrusion relative to the owning floor/screed, from the Settings part of the window, click Surface. Then pick the upper face of the floor/screed.

Set Hole Depth (equivalent to the thickness of the negative extrusion). A large depth makes it easy to see the volume of the negative extrusion once created. A depth slightly greater than the floor/screed thickness would normally suffice, since the application automatically adds 1mm to make sure that the hole always cuts through the referenced surface. The settings pane of the Create Negative Extrusion window is populated.

Use any combination of the methods used to create and modify negative extrusion vertices. Refer to Measure Distance for further information. You can now create the four vertices needed to define the required hole round the column. For ease of positioning, V1 and V2 can be aligned with the outer face of the column (although any position beyond the floor/screed edge is satisfactory).

When the four vertices are created, click OK. to display the Loop Vertex Editor window. The functionality of the Loop Vertex Editor window is explained. Refer to Modify Floor/Screed Definition for further information.