3D Direction from a P-line

Wherever a Design element or p-point is used for a direction, a p-line may also be used.

The p-line itself may be used for direction, or an axis of the p-line may be used.

The syntax for p-line direction is based on that in Design, as follows:

PPLINe word OF element_identifier

This defines the direction along the p-line in the Design. This syntax must be used if you wish to store the p-line in the annotation element.

PPLINe word OF element_identifier NEGative

This syntax specifies the negative or reverse direction along the p-line in the Design. This is equivalent to specifying the p-line -Y direction.

A direction parallel to an axis of the p-line itself may also be selected:

PPLINe word [OF element_identifier] [+] plxyz

PPLINe word [OF element_identifier] - plxyz

where plxyz is any one of:

X [DIRection]

Y [DIRection]

Z [DIRection]

LEAve [DIRection]

The axis of the p-line along the length of the Section is its Y direction. The Z or Leave direction and the X direction both lie in the plane of the perpendicular cross-section of the Section. The reverse of these directions may be obtained by the use of the minus sign.

Syntax for p-line direction qualified by <plxyz> cannot be used to set p-line attributes in the annotation. DIRECTION syntax of this form will be used to set the DIR attribute rather than p-line attributes. The following commands are examples of this:

NEW LDIM DIRection PPLINe word OF element_identifier LEAVE [DIRection]

NEW ADIM ON ...

FROM DIRection PPLINe word OF element_identifier -Z [DIRection]

TO DIRection PPLINe word OF element_identifier NEGative

However, the following command would actually store p-line data in the annotation element:

TO DIRection PPLINe word OF element_identifier

In this case the p-line direction has not been qualified by specifying an axis. Therefore the axis along the length of the Section is what is required and will be stored directly in the database as such.