Revit and Pizza fundamental Revit display concepts (View Range)

Revit and Pizza.

Other than both words having five letters each, you might be struggling to see the connection? Could it be that pizza is the order-in meal of choice for Architects working late on Revit projects?

While this is certainly plausible, the connection I am after has little to do with the pizza and rather concerns its delivery container: the pizza box. When explaining one of the most fundamental Revit display concepts (View Range) I often ask folks to imagine a large pizza box intersecting their building model.

The iconic shape of the pizza box turns out to be a perfect analogy for the proportions of the typical floor plan’s view range. After all, floor plans are much wider and deeper than they are tall; just like a pizza box!

So with that image in your mind, let’s discuss the view range.

When you took your first drafting class or first learned what a floor plan is, you were probably told to imagine a saw cutting through the building at a certain height above the floor, usually about four feet or 1,200mm, and then look straight down from this point. Elements cut by the saw would be drawn bold and those below this imaginary plane would be drawn lighter to indicate that they are off in the distance.

Revit quite literally makes this kind of slice through your building when determining what elements to display in a plan view and how to display them. The tricky part for many folks is, that it all takes place in a dialog box that can sometimes be a little difficult to understand.

The first step to getting a grasp on what all the settings in View Range do is to click the small “Show” button at the bottom of the dialog to expand an annotated image of the view range. This illustration gives a nice overview.

Items in the image are numbered from top to bottom, but I am going to discuss them in order of importance. The most important setting in the View Range dialog is item 2, the “Primary Range Cut plane.” In the saw analogy above, this is where the saw cuts the building. Thinking of the pizza box, this is the top of the pizza box.

Item 3, “Primary Range Bottom” is the next most important setting. And together with the cut plane, these two define the portion of the primary range where most elements live. The distance from bottom to cut is the height of our imaginary pizza box.

This region is critical because the general rule is that for an element to appear in your plan view, some part of it must fall within our imaginary pizza box. In other words, the element can be fully contained within the height of the pizza box, or simply cross through it. But if the object is wholly outside the pizza box, it will not display.

As with all rules, there are exceptions. So looking again at the “Sample View Range” illustration in the View Range dialog, we next consider item 1; “Primary Range Top.”

While the entire height from bottom to top (item 3 to item 1) is considered the “Primary Range” (Item 5). The zone between cut and top is a special zone.

Elements that fall within this zone, but are above the cut plane will only display if they are of the categories: Generic Models, Windows and Casework. All other categories must cross the cut plane to display.

The illustration shows a light fixture and a piece of cabinetry above the cut and within this zone. (Think of it like a second pizza box on top of the first one). In the corresponding plan view, only the cabinet (which is Casework) element would appear. The light fixture (which is not one of the three categories) would not.

If you consider the next image, which contains several items of varying categories, notice that of all the items that occur above the cut plane (green dashed line in the image), only the wall mounted cabinet (on the left) and windows display. The roof and several specialty equipment items do not.

It is sometimes desirable to have items of categories other than Generic Models, Windows or Casework to display above the cut. For example, wall mounted lighting fixtures are often shown on floor plans.

The solution to such items is simple. Edit the family and add some invisible geometry that intersects the cut plane. You can see examples of this technique in the lighting fixture content included with Revit.

A simple invisible line is drawn vertically from the bottom of the fixture to the floor. Since this invisible line intersects the cut plane, the element will display in plan views. If this line is not included, then the item does not display in plan as seen on the right in this image:

So, what happens below the primary range?

Imagine a final pizza box occurring below the bottom. But first you must enable this zone.

To do so, you must move item 4; the “View Depth Level” down. This enables item 6; the “View Depth.” Within this zone, any category is eligible to display.

However, a special rule is applied to all elements that fall inside this lower pizza box. Instead of using their normal display properties, their linework is overridden with a special line style called: <Beyond>. You can find its settings in the Line Styles dialog (available from the Manage tab, from the Additional Styles drop-down menu).

Configure <Beyond> to your needs, and then you will see this line style applied to all elements that fall in the View Depth zone. Like the footings in this image: 

I hope all this talk of pizza has not made you too hungry.