Fixtures, Fittings, & Furniture

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Overview

In this lesson, students explore techniques for creating and adapting components to model fixtures, fittings, and furniture. They will learn how to:

Create in-place components to model project-specific elements and geometries.
Adapt existing component families to meet their needs by adding and removing forms as well as assigning materials.
Create new component families and add parameters that enable them to dynamically resize the components and change their materials.

Using Component Families

Autodesk® Revit® software enables you to use and create component families that can be easily modified to help meet the requirements of different projects. It offers great flexibility and to help increase your modeling productivity. You can easily change the parameters defined for existing component and create new types as needed with different dimensions, appearances, visibility, and performance characteristics. By creatively working with the parameters available, you can often adapt a single component family to model a wide variety of elements in your project.

Modeling In-Place Components

You can use the Model In-Place tool to create unique components when a suitable component family does not exist. The Model In-Place tool affords the designer flexibility and creativity in designing and specifying custom, one-of-a-kind components for use within a single project.

Revit software offers five methods to create model geometry:

Extrusion—pushes or pulls a 2D Sketch Profile along z-axis of Work Plane that the sketch was created in.
Blend—3D shape extrapolated from two 2D Sketch Profiles, one at bottom and another at top of shape, with blend depth determining transition between top and bottom shapes.
Revolve—creates 3D shape by revolving a 2D Sketch Profile about specified axis.
Sweep—drives a 2D Sketch Profile along a planar 2D Sketch Path.
Swept blend—3D interpolation of two different 2D Sketch Profiles, each on located at opposite ends of a planar 2D Sketch Path.

These five methods can be combined to create almost any geometry required.

Adapting Components to Fit Your Needs

You can adapt existing component families to model objects with similar geometries. This approach is especially effective when components are available that have many common characteristics but are not exactly what you need. Rather than starting from scratch, it is often easier to edit an existing component family and change only the parts that are different.

You can open an existing component family in Revit software’s family editor in two ways:

Open the Revit family file using the Open command in the Revit menu, then choose Family in the submenu.
Select an existing component placed in your project, then opening the Edit Family tool.

Either method opens the Revit family editor, where you can explore the existing forms (extrusions, blends, revolves, and sweeps) defined in the component and edit their properties as desired to create your component.

Be sure to save the adapted component using a new family with a new filename to avoid accidentally overwriting the existing version.

Creating New Families

You can also create new component families from scratch to model objects that cannot be easily adapted from an existing component.

You create new components by opening the Revit family file using the New command in the Revit menu, and then choose Family in the submenu. Choose a template from the library that determines the category and hosting conditions for your component, and then define the component using tools in the Revit family editor:

Reference planes to establish the key boundaries.
Dimensions and parameters to dynamically set their location.
Solid and void forms (extrusions, blends, revolves, and sweeps) to define the parts of the components.
Materials and parameters to dynamically assign them.

As you define new parametric components, plan the critical dimensions that will drive the geometry carefully. Be careful not to over-constrain the forms by locking too many dimensions or adding too many parametric constraints. This is a common pitfall, and Revit will warn you when all the constraints defined cannot be met. When this happens, examine the constraints that have been added carefully, determine which constraints are in conflict, and remove the constraints that are not truly needed.

Well-designed parametric components greatly improve your modeling efficiency, because they enable easy modification and repurposing by simply creating new types and adjusting the type and instance properties. While mastering the skills required to create new parametric component families can be challenging, the time is well invested and yields tremendous returns.

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Learning Objectives

After completing this lesson, you will be able to:

Understand when to create unique components when suitable component families do not exist.
Explore the various techniques for creating custom geometry, including extrusions, blends, revolves, sweeps, and swept blends.
Appreciate the value of adapting existing components into custom components.
Understand the techniques for creating new parametric families from scratch and loading them into projects.

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Tutorials

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Modeling In-Place Components

In this exercise, students will learn how to:

Use the Model In-Place tool to create project specific custom forms.
Create simple extruded shapes and set the extrusion’s thickness and material properties.
Combine and resize extruded shapes to model common building elements, such as furniture objects.

Figure 1.5.1. Using the In-Place editor to model counters by extrusions

Video Tutorial

Student Exercise

Unit1_Lesson5_Exercise1_Start.rvt

Last modified by Glenn Katz 14 years ago

drive.google.com

Open the Ground Floor plan view of the project model.
Create an in-place component to model a dining room table that fits the unique triangular geometry of the walls.

Create the table using two separate extrusions: one for the table base and another for the table top. The table top should be 4-inches thick with its top surface located 32 inches off the floor. The table base should extend from the floor to the bottom of the table top.
Choose a material for these extrusions that is similar to cherry wood.

Use the Place Component tool to place chair components of type Barrel around the custom table as shown in Figure 1.5.2.

Figure 1.5.2 - In-place component for dining table with barrel chairs placed around it

Model a custom-shaped bed as an in-place component for the nonrectangular master bedroom as shown in Figure 1.5.3. Since the bed needs to conform to the irregular geometry of the walls, it requires a custom component.
Model this in-place component using three extruded shapes to represent the following parts: the bed platform, the mattress, and the headboard.
Use void forms to cut openings in the headboard for books and bedsides accessories.

Figure 1.5.3 - In-place component for bed in master bedroom

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Modifying a Family Definition

In this exercise, students will learn how to:

Utilize existing component families to adapt them for new uses.
Add new forms to the families and change the instance parameters.
Assign new materials and dimension properties.
Define new component family types and load them into a project.

Figure 1.5.4. Defining new bed types by adapting an existing object

Video Tutorial

Student Exercise

Unit1_Lesson5_Exercise2_Start.rvt

Last modified by Glenn Katz 14 years ago

drive.google.com

Edit the family of the floor lamp near the sofa in the living room of the residence to create a new one with a mid-century modern look.
Modify the lamp shade form:

Save the component family using a new name to avoid overwriting the original. Name the new component Floor Lamp – Modern.
Delete the center pole element, which is defined as an extrusion
Select the lamp shade, which is defined as a revolve

Open the front elevation view, and edit the revolve. Change the sketch of the boundary lines to create a funnel shape as shown in Figure 1.5.5.

Figure 1.5.5 - Updated boundary sketch and revolved form for lamp shade

Modify the lamp base form:

Select the lamp base, which is also defined as a revolve.
Open the front elevation view again, and edit the revolve. Change the sketch of the boundary lines to create a cylinder shape as shown in Figure 1.5.6.

Figure 1.5.6 - Updated boundary sketch and revolved form for lamp base

Add three legs to support the lamp shade:

Open the front elevation view again, and create a new solid extrusion.
Sketch boundary lines that meet the sides of the lamp shade and lamp base as shown in Figure 1.5.7.
Set the extrusion start to 1/2" and the extrusion end to 1/2" to create a 1" thick leg.
Finish the extrusion.
Open plan view and use the Array tool to create a radial array of 3 legs spaced evenly around the center of the lamp (with a rotation of 120 degrees between the elements).

Figure 1.5.7 - Boundary sketch for leg extrusion and radial array of 3 legs supporting lamp shade

Modify the light source definition to match the new lamp shape:

Select the current light source definition, which is also defined as a hemisphere.
Open the Light Source Definition tool and choose to emit light using the line shape and the spherical light distribution pattern.
Open the front elevation view again, and select the light source element.
Unlock the constraints on the light source, and rotate it 90 degrees. Then move the center of the light source down 2' as shown in Figure 1.5.8.

Figure 1.5.8 - Updated shape and placement of light source

Assign materials for the lamp shade, base, and legs:

Open the Materials dialog box, and duplicate the Default material. Name this new material Modern Lamp Base, and assign a brown color as the shading to represent wood.
Duplicate the Glass – Frosted material and name the new material Modern Lamp Shade.
Open the 3D view and select each of these elements to assign their materials in the Properties palette.
If the leg elements are in a group (created during the array operation), select one leg and edit the group. The material assigned to one leg will automatically be used by all legs.

Save your work and use the Load into Project tool to load the new component into your project.

Figure 1.5.9 - Completed modern lamp component

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Creating New Families

In this exercise, students will learn how to:

Use the family editor to add reference planes, dimensions, and parameters.
Test parameters and define family types.
Create forms, set constraints, and assign materials to forms.
Save, load, and place instances of a custom component family.

Figure 1.5.10. Testing custom component parameters

Video Tutorial

Student Exercise

Unit1_Lesson5_Exercise3_Start.rvt

Last modified by Glenn Katz 14 years ago

drive.google.com

Modify the console table component created in the tutorial by editing the family to add additional parametric features. Change the tabletop from a 4" slab of a single material to two pieces—a table surface and a table frame whose thickness and height can be resized parametrically.
Start by adding reference planes and parameters to control the thickness of the frame:

Open the reference level plan view.
Add new reference planes on all four sides of the table. Place these 1" away from the existing reference planes that define the tabletop boundary toward the center of the table as shown in Figure 1.5.11. It may be helpful to use the Pick Lines tool to place these planes using a 1" offset from the existing planes.
Add a dimension from the existing reference plane to the new one on each side of the table
Select one of the dimensions and add a parameter named Frame Thickness. This should be a type parameter of type length grouped under the Dimensions section of the properties.
Select the remaining 3 dimensions and set the Frame Thickness parameter as the label for each of them.

Figure 1.5.11 - New reference planes controlled by Frame Thickness parameter

Add an opening to the existing tabletop extrusion to create the table frame:

Select the existing tabletop extrusion and edit it.
Sketch a new rectangular boundary inside the existing one to create an opening.
Align the edges of this new opening to the reference planes and lock them in place.

Figure 1.5.12 - Sketch of opening creating the table frame

Create a new extrusion to model the table surface using a solid extrusion with a rectangular boundary that is constrained (locked) with the reference planes.

Open the Solid Extrusion tool.
Sketch a new rectangular boundary inside the frame.
Align the edges of this new extrusion to the reference planes and lock them in place.

Figure 1.5.13 - Sketch of table surface within frame

Add reference planes and add parameters to control the height of the table frame, the table surface, and the pedestal base:

Open the front elevation view.
Add new reference planes about 1" below the existing reference plane that defines the top of the table as shown in Figure 1.5.14.
Add a dimension from the existing reference plane to the new one.
Select this dimension and add a parameter named Surface Thickness. This should be a type parameter of type length grouped under the Dimensions section of the properties.
Select the existing dimension that controls the thickness of the tabletop and add a parameter to it named Frame Height. This should also be a type parameter of type length grouped under the Dimensions section of the properties.

Figure 1.5.14 - New reference plane and parameters to control thickness of table frame and surface

Lock the top and bottom surfaces of the extrusions to these reference planes:

Switch to the wireframe visual style to see all three extrusions clearly.
Align the top of the table surface extrusion to the table top reference plane and lock it.
Align the bottom of the table surface extrusion to the middle reference plane and lock it.
Align the top of the pedestal base extrusion to the middle reference plane and lock it.
The table frame should already be locked in place, because it was created by modifying an existing form.

Assign a material to the table surface and add a new instance parameter to enable users to dynamically change this material:

Open the 3D view and select the table surface form.
Click the small button that appears in the material value field to open the Materials dialog box, and choose Glass as the default material for this form.
Click the small button that appears to the right of the material value field and add a new parameter to control this material setting.
Name the parameter Table Surface, and define the parameter to be an instance parameter of type Materials grouped under the Materials and Finishes section of the properties.

Save the family and load the new component into your project.

Duplicate an existing type to create several new types with different sizes by experimenting with the parametric dimensions. Change the proportions of the table frame and the pedestal base to model a wide range tables, benches, and similar objects.
Place several instances in your project, and assign different materials to the table frame, table surface, and pedestal base for each instance to vary the resulting look and application.

Figure 1.5.15 - Two instances of the console table component placed in the residence showing different sizes (type properties) and materials (instance properties)

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Assessment

Modeling In-Place Components

What types of objects do you typically need to model as in-place components?

You will typically model in-place any object where their shape depends on the geometry of the surrounding walls or elements, for example, countertops and casework are typically sized to match the precise distance between walls.

In the example house, with its unique triangular geometry, many of the furniture elements and plumbing fixtures would have to be modeled as in-place components.

Can you copy/paste to duplicate in-place components? Can you reuse your in-place component in another project?

We can copy and paste to the clipboard within the same projects or even to a new project. However, we cannot copy and paste between projects and families. So in-place components cannot be easily converted into reusable component families.

What factors determine whether a component should be modeled in-place or using the family editor?

The question is whether the component’s geometry is project specific or whether the shape is the sort that is compatible and easily resized for use in other projects.

Adapting Components to Fit Your Needs

Which forms in the lamp component could be modeled in other ways (for example, as extrusions rather than revolves)?

Many answers are possible. For example, the lamp base could be modeled as an extrusion of a round shape or by revolving a rectangular shape.

For which characteristics of the modern lamp would it be useful to vary parametrically by defining new types? By changing instance properties?

It is most useful to set dimensions as type properties because they have a drastic effect on the component in terms of spacing and compatibility issues. Characteristics that we want repeated many times should also be considered type properties.

For simpler characteristics, such as materials, we can use instance properties. These changes will only affect the instance being modified and it will help to create variation.

Are materials assigned in the component definition automatically loaded into a host project? Where do they appear?

Yes. The materials assigned a component family definition are loaded into the host project and appear in the Materials dialog box under the same name.

Creating New Families

What are the advantages and disadvantages of creating single components with many parameters to create variations versus creating many independent component families?

By creating one component with different parameters, we are enabling multiple variations without the extra work or time it takes to create new families. However, we are also being locked into certain constraints when using a specific family. In order to expand upon a family and to be even more creative, it is better to create a new family. This enables unlimited variation, instead of only the limited changes prescribed to us in a predefined family.

When would it be useful to define a relationship between parameters with formulas?

Formulas should be used when a parameter is dependent upon another parameter. If there should be a shelf for every three feet of cabinet, a formula should be used. If a table’s width should always be half of its length, a formula should be used. Independent parameters do not need formulas.

What types of constraints can be added to a component definition to prevent users from creating impossible geometries?

Formulas can be added to parameters to ensure that the values specified are within valid limits. For example, if a parameter is used to specify the size of an opening in a form, you can set up a formula to ensure that the size of the opening never exceeds the boundaries of the hosting form.

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Key Terms

Key Term	Definition
Parameter	A detail that can be changed or adjusted―includes dimensions, materials, and offsets.
Parametric Component	A component―such as a piece of furniture, a door, or a window―that is composed of adjustable parameters used to create variation within our model.
Family	A group of components with different settings for the same parameters. Each type is based on the same initial model but usually has different dimensions.