Simple Mass Modeling in Revit

Introduction

Within Revit, Mass Modeling is a fast way to draw conceptual volumes. There are two ways of creating a mass. The first is by creating a Conceptual Mass Family, which is a mass that is created outside the project. The second is by creating an In Place Mass. This is a mass that is created within the project. In this tutorial we explain how to create an In Place Mass.

Setting up the guidelines

Before actually creating your mass, it's good practice to create some guidelines first. Grids and Levels give you the possibility to snap your geometry to predefined dimensions.

Changing Levels

• Go to the Project Browser and open an elevation view and create your desired levels, adjust them to the right height and give them a sensible name.

Adding a Grid-line

• The second step is to create grid lines. Change your view to a floor plan and create your desired grid.

Creating an In Place Mass

In Place Mass

Once we have our guidelines set, we can start creating our Mass.

• Go to the Floor Plan where you want to create the mass.
• In the Ribbon, select the Massing & Site tab and click In Place Mass. When it is the first mass to be created within the project, a pop up will appear stating that Revit has enabled the Show Mass mode. Click Close. (If masses are already visible the Show Mass mode is already turned on and this pop up will not show)
• Next a pop up will appear asking for a name for the mass. Give it a sensible name.
• Now we can create the outline of the mass. We can either do this by drawing Model Lines or by drawing Reference Lines. Model Lines will disappear after creating the mass. Reference Lines will remain so they can be used as a basis for additional masses.
• First choose or make a construction plane with the Set button on the Work Plane tab. With the Tab key you can cycle through planes of objects while hovering the mouse pointer over them, even (end) of (reference) lines.
• Sometimes to many objects (everything in Revit is an object) are in the way. Select what you want to temporarily hide and hit 'hh' (twice the h-key). Or select what you temporarily want to isolate and hit 'hi'. To reveil what is hidden, hit 'hr'.
• You can draw several types of lines to make a profile for the 3D form. If you combine them into a closed non-intersecting shape, and hit Create Form, Revit will show in the next step two possibilities you can click on: a flat surface (if the shape was flat) or a 3D form as a result of an extrusion. This means that a path is used perpendicular to the shape, like if the shape is repeated along that path.
• But you can also select several non-intersecting curves (closed or not). In that case Revit will try to create a loft. This means that a fluent form is created with the curves as sections.
• Or if you select a curve and a straight line on the same plane, Revit will try to make a revolve. This means that the form is made as in pottery: rotation around the line.
• If you select the work plane at the end of a curve and create a second curve there, Revit will try to make a sweep. Meaning that the first curve is used as a path, along which the second curve is repeated.
• Notice that you can turn on 3D snapping in the option bar, which allows to go outside the construction plane.
• You can mirror, align, cut etc. profile elements with buttons in the Modify tab. Use an aligned dimension to e.g. move a cut to the middle of a profile element by clicking on a reference line, the cut point (use your Tab key) and another reference line and hit the EQ button that appears next to the dimension. Notice that the dimension object belongs to a construction plane.
• When you select a finished mass in the project, Revit will display in the properties window the total area of all the mass surfaces and the volume, but not the floor area. However if you select the mass and hit the Mass Floors button in the Modify|Mass tab you can create mass floors and the gross floor area will be shown in the properties window. It is annoying that you can't see the floor area while creating the mass. A solution is to make an area parameter (hit the Family Types button top left) and use formula's to calculate the area, but this is for advanced Revit users.

Create Form

• Go to a 3D View and select the top of the shape. Sometimes it seems you are not able to select the top surface. By clicking the Tab key on your keyboard, you can cycle through the elements that are possible to select for a certain mouse position, like surfaces, edges and corner points. Sometimes you first have to unlock the element.
• When the top surface of the volume is selected go to an elevation to move the surface by using the arrows. You can snap to the desired Level. You cannot only do this for surfaces, but also for edges and corner points.

Selecting the Volume and Moving Surfaces, Edges or Corner Points

• By removing edges and/or corner points, you can create different shapes like a common roof.
• To stack masses on top of each other, just go the Floor Plan of the level above, and create a new mass.
• Create all the masses until you are satisfied with the shape of the combined masses and click Finish Mass.

Creating a Void Form

Create Void Form

• Select the Mass and clicking the Edit Mass button
• Go to the Floor Plan where you want to create the void form.
• Now we can create the outline of the void form.

Edit Void Form

• Draw a closed shape. It can be any shape, just make sure it forms a closed loop.
• Instead of selecting Create Form select Void Form from the dropdown menu.
• You can edit the void form similarly to the solid forms, to move and/or remove edges
• Click Finish Mass to subtract the void form from your original mass.

Changing the appearance of an In Place Mass

By default masses are created with some sort of semi-transparent appearance. To change this, we have to change the material settings of the mass. You can do this by clicking the Edit Mass button. By selecting the entire mass you can change the material for all the objects within the mass. If you select individual surfaces (by using the "Tab" button) you can allocate multiple materials within one mass.

• Once you have made your selection, in the Properties window, behind Material a small button with some dots appears in the upper right corner of the cell. Click this button to enter the Material Browser window. Or hit the button next to it and create a material parameter. Once you finished the mass, you can set the material then in the project (easier to evaluate the effect in the whole situation).

• Select a suitable material, or create a new material by clicking the small sphere under the material list.

• Right-click the "New Default Material", select "rename" and give it a sensible name.
• Under the Graphics tab, set the Color and Transparency to your desired settings and click OK.

• Click Finish Mass.
• Make sure to set the view mode to Shaded, to be able to see colors.