Category: Revit, Visibility

Revit View Filters 201

In the previous blog post I shared some basics on filters – what they are, how I approach them, and how I use them. Now it’s time to get into the nitty gritty and look at how to create filters! When creating a new filter, you specify the name, select the categories to be included in the filter, and then define the rules.

View Filter Naming

Naming is very important for filters. I have said this before and I’ll say it again, a critical thing to understand with filters is that after filters are added to a view, the main function they provide in terms of visibility is to turn the Visibility off. Therefore, name the filter so that you and other users know what is being turned off.

View filters can be categorized as inclusion filters and exclusion filters. It is important to distinguish between these when naming the filter. For example, does it include chilled water piping or not include chilled water piping? I simply add “NOT” to my exclusion filters. Just remember that descriptive naming will help the team know how to use the filter.

View Filter Categories

The next step is to select the appropriate categories to include in the filter. For example, if you want to create a filter for domestic chilled water piping, then you want to include all of the categories that could be included in that piping system. In the image below, all the piping categories are selected. That means any element belonging to those categories will be picked up by the filter when they meet the rules.

Another thing to keep in mind is something that is stated under Categories in the Filters dialog. Parameters common to the selected categories will be available for defining filter rules. Let’s take a look at an example. You will notice that the Piping Systems category is not selected in the image above. So you may be thinking, if we’re creating a filter for a piping system, why not include that category? The reason is because systems are logical entities. They are not model elements. Model elements are assigned to systems, but they do not belong to a system category.

So in our example, when it comes to defining filter rules, there are several common parameters available when just the model categories are selected. In other words, when Piping Systems is not selected.

When the Piping Systems category is selected, then the list of common parameters is significantly reduced. There are still parameters that can be used, such as System Classification or System Name, but you really don’t gain anything from adding the Piping Systems category. It doesn’t affect visibility and it doesn’t affect the graphic display of the model elements.

View Filter Rules

Finally, you need to define the rules for the filter. If you haven’t figured it out by now, the common parameters for the selected categories are used to define the rules. And depending on what you are trying to do, you need to have specific naming conventions to help you with filter rules. Before we get too far into the weeds, let’s start with some basics here.

Rule-based filters are comprised of rule sets and rules. In other words, you create rules inside of rule sets. You can have multiple rules in a rule set and you can have multiple rule sets. There’s actually no limit to the number of rules and rule sets you can define. However, I have to think at some point it would be too hard to track it all!

I always try to keep things as simple as possible to accomplish the outcome. If you try to get too complex, you can have conflicting filters or maybe even conflicting rules. You can do quite a bit with one rule set and one or two rules. When you first start, there will be a default rule set. The condition for a set can be one of the following:

  • AND: All of the rules and nested rule sets must be true for elements to be picked up by the filter.
  • OR: At least one of the rules or nested rule sets must be true for elements to be picked up by the filter.

If you just have one rule, then leave it set to AND and create the rule. The rules should come pretty natural to you based on what you want to pick up in the filter. I’m realizing now that I may need another post to cover some more examples, so I’ll end with a few tips…

When I create duct system types and piping system types, I use a prefix in the type names. That way I can create filters for groupings of systems as well as individual systems. So the rules for inclusion filters are ‘System Type begins with’ and then ‘System Type equals’.

When creating a new filter, you specify the name, select the categories to be included in the filter, and then define the rules.

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