Backing and Overlay Sheets

2D drafting may be used to create backing and overlay sheets, or may be used to annotate overlay sheets that exist as VIEW elements. The relevant part of the Draft database hierarchy is shown in Figure 18:1 below.

Figure 18:1. Draft Database Hierarchy - Sheet Library/2D Drafting Elements

A BACK (backing sheet template) element would probably be used as a frame sheet and would contain frame lines, authorisation boxes. These would exist as (member) NOTE elements (see below).

OVER (overlay sheet template) elements may also own NOTEs as well as VIEW elements, and would probably be used to overlay graphic details such as keyplans on drawing sheets. An OVER shares many of the attributes of a SHEE.

Sheet Note (NOTE) elements exist to own the 2D drafting elements themselves (see The Drafting Elements). This means that NOTEs can be used to ‘group’ drafting elements together - changes to the NOTE’s position and orientation will affect all of its member drafting elements. As well as the basic attributes of XYPS (2D Sheet position), ADEG (orientation) and LVIS (visibility), NOTEs/VNOTs have a set of attributes that are used to store defaults values that are cascaded down to their members. These are:

The first three are cascaded to geometric primitives and the others to text primitives.

View Note (VNOT) elements are similar to NOTEs, the only difference being that VNOTs may be positioned using 3D Design World coordinates or on a Design item, p-point or p-line (or using 2D Sheet coordinates).

Having created a NOTE or VNOT in accordance with the hierarchy shown in Figure 18:1 above drafting elements may be created and manipulated as desired - see The Drafting Elements.