Component Visibility, Drawing Level and Obstruction

2D and 3D geometry components have a number of attributes that control the representation in the graphics window. The most important of these attributes are:

Tubeflag

The Tubeflag attribute may be set to TRUE or FALSE (the default) and is effectively an ON/OFF flag for component visibility. For structural geometry components it is essential that Tubeflag is set to TRUE, i.e. ON.

Level

The Level attribute contains two numbers indicating the inclusive range of the drawing levels that the component will be displayed on, e.g. if a components Level attribute is set to 4 8, the component will be visible on drawing levels 4 through 8 inclusive in the graphics window.

For SPRF components it is usual to create three geometry definitions with the appropriate components on different drawing levels, for example:

Simplified: Level 0 – 4 Obstruction value 0

This representation is used in Draft if an isometric view of the profile is required.

Actual: Level 5 – 8 Obstruction value 2

This representation is used for most 3D and 2D graphics as it is the true representation of the profile.

Obstruction: Level 9 -10 Obstruction value 1

This representation is used for the obstruction volumes of the profile.

Obstruction

The Obstruction attribute informs the clash detection facility whether a geometry component should be considered as:

The SANN, SREC and SPRO creation sub forms have a Representation option that enables pre-set values for Level, Obstruction and Tubeflag to be set. The following table gives the details of the Representation available: