by Dennis Collin
Controlling how elements are displayed in Revit is a frequent question received from users. I recently posted on how Revit prioritises the display of regular Revit elements like slabs, beams, and walls, but what about MEP systems? When working in busy areas such as plant rooms, additional display options are required for MEP systems to distinguish between the different service types more easily.
To achieve this, graphic overrides can be specified for duct and pipe system types. These systems can be located under the family listing of the project browser.
Fig. 1. Creating additional system types
To create a system type, duplicate an existing system and name it appropriately, the process is the same for both pipe and duct work elements.
Type properties can be set for colour, line type and line weight to distinguish elements of the same category but belonging to different systems.
Fig. 2. In most cases a system type will have display overrides set.
In this example a duct system type called ‘ demonstration’ has been created. If no display overrides are specified, the elements will revert to display controls in the first instance to Project Object Styles. Alternatively, if visibility graphics overrides (VG) have been applied the latter will take priority.
Fig 3. Supply Air duct system typically colour coded as blue.
In most situations however duct and pipe systems will have some or all these settings overridden. In terms of ductwork Supply Air is usually coloured blue, Return Air as magenta etc, but where does this display priority sit between the more commonplace Revit display controls?
Graphical overrides for a system are prioritised between Category and Filters options, weight, colour and line pattern of the system type will override the by-category settings. However, a view filter will override the settings in the system graphical override properties.
Fig 4. With no colour override set Ducts and their fittings will follow VG Category display rules. (see below) But system-coloured entities will retain their properties unless Filters or Element overrides are applied.
I have attempted to clarify the priorities with the following table (figure 4a), with the overrides being listed in a priority order; instance override listed at the top and object styles at the bottom. Instance overrides all, including filters, phase, system, VG category and object style. This can be seen with the green ticked cells. A red cross marker indicates that the override will defer to a control of a higher priority. Note Object Style defers to all other override controls. Whereas MEP system types sit somewhere in the middle of the listing, providing users the necessary flexibility of display control.
Fig 4a. Table listing override priorities from Instance (1) to Object Style (6)
Should some special instance need to be highlighted element overrides or filters can be applied.
Fig 5. Phasing (3) and Object Style (6) not shown on diagram.
Colour coding MEP elements makes the model easier to understand and fault trace.
Working efficiently and maximising the use of Revit content and display issues are just some of the topics that ARKANCE provides on Revit training courses. Visit the Arkance UK site to get an overview of the courses on offer and talk to one of the team for dates and availability or if you have more bespoke requirements, please just ask, we are here to help!