Updated: Aug 3, 2019
Just like how cold clean air injected in a combustion engine boosts horsepower in hot rods, filters boost your power in Revit. Filters have virtually limitless applications in Revit and can be used to control visibility, provide feedback on your design and help you compose engaging infographics.
Know Your Type of Filter
You would not go to your local auto parts store and buy just any filter for your car, you would make sure the filter is designed specifically for your vehicle. The same approach needs to be employed when using filters in Revit; you first need to know which type of filter best suits your project's needs. There are two main types of filters; Rule-based Filters and Selection Filters.
Rule-based filters are by far the more robust type of filters. Rules can be composed to address almost any situation that can not be handled by category level overrides in a view. For example; let's say you were developing a floor finish plan and wanted to have a color-coded infographic that gave an overview of the floor finishes for your project. Your first thought might be to use a Color Scheme for the view and use the Floor Finish parameter for the rooms. If you have more than one finish in a room; perhaps hardwood in one area and tile in another, you would be sunk. A rule-based filter based on the type name for the floor finish would be your savior here.
Let's go through the mechanics of how to create a rule-based filter. They are most effectively applied to View Templates. If you are not using View Templates, you are creating more work for yourself and we cannot be friends. You can navigate to Filters through several different paths, I find myself getting there most often through the Visibility Graphics Filters button of my View Templates.
By clicking the Edit button next to V/G Overrides Filters, the Visibility Graphics Overrides dialog will come up and you will be landed on the Filters tab. From here you can see which filters have been applied (if any), you can add new filters, re-order the filters applied to the view or view template and so on. Filter order is critical in views, Revit processes them from a top down direction with those taking precedence at the top. If two filters conflict in some way, the filter at the top will win out.
To create a new Rule-based filter, click Edit/New. In the example below we will be creating a filter to capture all the floors with a wood finish.
Next we will apply graphic overrides to the objects that are included in the filter selection. One of the great things about Rule-based filters is that it applies to all objects in the view that meet the criteria of the filter; whether they exist in the view now or they are added later. In the example below we are adding a solid fill override to each of the floor types visible in the view.
Let's now go through another common example demonstrating how to use Rule-based Filters in Revit. There are many times when you need to show mechanical equipment in a view but not all mechanical equipment. Take the example of the Power Plan. The electrical engineer needs to show all the equipment needing power but having equipment shown not needing power can be a distraction or worse it may be confusing. Much like we use reverse psychology with people, we employ the same tactic with Revit by telling it what we want turned off instead of what we want turned on.
Selection Filters are completely different from Rule-based filters in that instead of using a wild card selection criteria, the objects included are included exactly as the name implies, by selecting them. As you can see below, once two or more objects have been selected you have the opportunity to save them as a Selection Set. Note that the Selection Set shown below contains objects from multiple Revit categories.
Now that we have a Selection Set defined, we can add the selection set to our View Template just as we did with the Rule-based filters and then apply overrides as needed.
So what if you need to add or remove items from the selection set at a later time? Simply select two or more objects, then click Edit on the Contextual Ribbon.
One of the key differences between selection based filters and Rule-based filters is that as new objects are added to the model, they will not be added to selection sets automatically. Depending on the application this may be OK.
As you can see, there is great power and flexibility with filters. They can be built to address a seemingly limitless number of challenges.