Looking Direction

The View’s line of sight is fully defined by any two of:

• Looking Direction

• From Point

• Through Point

which are defined by the attributes DIR, THPO and FRPO. Setting one of these will unset one of the other two, assuming they are both already set.

DIR (Direction) specifies the Looking Direction, down by default. This attribute is set by commands such as

LOOK E

LOOK N45W

ISO3

PLAN

ELEVATION N

IR D

Note that the picture produced by changing the Looking Direction may not necessarily fit into the VIEW frame.

The THPO (Through Point) attribute is set to the Design coordinates corresponding to the centre of interest of the view. These will be calculated automatically from the VIEW’s related Id List by the AUTO command.

FRPO (the From Point) is the position (in Design coordinates) at which the observer is deemed to be.

The Through Point and From Point may be set explicitly by commands such as:

LOOK THROUGH N53426 W632764 U2125

LOOK FROM N53426 W632764 U2125

FRPO N125671 E67342 U11254

THPO N125671 E67342 U11254

Changing the Direction, Through Point or From Point will make the existing VIEW graphics out of date, so this must be updated by typing UPDATE DESIGN before any change in the picture will be seen.

The 3D view direction equivalent to 2D Sheet direction may be queried using

Query VIEWDIRection <sheet-dir>

where <sheet-dir>is Left, Right, Up or Down. This command gives an error when the VIEW has Perspective or the current database position is not at or below a VIEW.

For example, in a plan VIEW with RCODE UP (the default), then the query

Q VIEWDIR LEFT

would give:

Viewdirection Left W

However, for a plan VIEW with RCODE LEFT, the result would be:

Viewdirection Left N

and for a plan VIEW with ADEG 120 (and RCODE UP) the result would be:

Viewdirection Left E 30 N