Lesson 5: Families and Components
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.
After completing this lesson, students 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.