Boolean Geometry Operations

DesignBuilder provides some very powerful modelling tools for combining blocks in various ways to create new more complex geometric forms. Boolean geometry (otherwise know as Constructive solid geometry or CSG) provides these functions:

 

  1. Union, where 2 blocks are combined into a single new block.
  2. Difference (subtract), in which one block is subtracted from the other to form a single new block.
  3. Intersection, where a new block is formed where the 2 original blocks intersect.

The union operation can be applied to any block including building blocks, whereas the difference and intersection methods only apply to outline blocks because these are the only block types that allow the block intersections required for these operations.

Using the Boolean Operations

The first step in using the boolean operations is to go to building level and select 2 blocks to which the command is to apply. When 2 blocks are selected the Boolean geometry toolbar icon is enabled and pressing on the toolbar icon at this stage starts the command and the Display options panel is displayed in the bottom left of the screen. On this panel there is a drop list with the 3 boolean functions available for selection. In the case where 2 building blocks are selected, only the Union operation is allowed, because building blocks cannot intersect and the difference and intersection options require intersection to work.