In my work as an educational facility planner, I use Autodesk® Revit® to draw floor plans and to create 3D models of the facilities on which I am working. The information contained in the models is used to create the facility master plan. While the master plan is valuable, I have been looking for a way to share the models and the information they contain in digital form with my clients. The easy answer is to submit my Revit files; however, my clients have no need for a full version of Revit nor do they have the expertise to use it. My solution has been to submit my models as a 3D PDF. By exporting my Revit models to IFC, I am able to import both the geometry of the model as well as the data contained in the model in to an interactive PDF file that can be viewed from the free Acrobat Reader. In this article, I will show how a 3D PDF can be used as a viewer for Revit models and offer some suggestions on how to expand their use in your practice.
From RVT to IFC, then PDF
Once you have completed your Revit model, the first step in creating a 3D PDF is to export the model using the IFC option.
Figure 1: Exporting the sample model to IFC.
Before exporting you can view what element categories will export by selecting R -> EXPORT -> OPTIONS -> IFC OPTIONS. Each object is assigned to an IFC Class; for example, Areas exports to IfcSpace. If you are familiar with the IFC Classes, you can modify the default settings in the options. Once your model has been exported, the next step is to import it into a PDF. You can create a PDF from a file, from a blank page, or from a 3D capture. I have had very little luck importing a Revit model through the 3D capture.
Furthermore, we want to import the IFC data with the model, so a capture may not be the right choice. The simplest option is to create a PDF from a blank file. To import your IFC model, go to Tools -> Multimedia -> 3D Tool and draw a box on the blank page. After drawing the box, you will be presented with a window asking for the location of the IFC file as well as some options for displaying your model.
Figure 2: Select your IFC file and modify any of the default settings.
Save your PDF and you now have an interactive 3D PDF. The PDF can be viewed by anyone using the free Acrobat Reader. One benefit of placing your IFC file into a PDF is that the file becomes much smaller. The IFC file used to create the PDF is 5.19MB and the finished PDF is a mere 424KB.
How to interact with your model
When you open the PDF in Acrobat Reader, you may have to click to activate the 3D content. The main window contains the 3D model.
Figure 3: Model tools and options
The three boxes on the left are the model tree, the views (if any have been predefined), and the properties, which will be displayed when an object is selected in the model or in the tree.
Interact with your model as you would most other 3D programs: Scroll your mouse wheel to zoom in and out, left click and move your mouse left, right, up, and down to move the model. For other controls and to modify the model, there is a toolbar floating above the 3D model box. These tools allow you to change the appearance of your model. You can select predefined views, change the rendering mode, change the lighting used in the model, change the background color, and cut cross sections through the model.
Interacting with the model in the PDF has been much more intuitive for my clients. The limited number of tools and menus, as well as the ability to work in a program with which they are familiar makes them feel comfortable, confident, and more willing to interact with the model.
Viewing the IFC data by selecting objects
The data in my models is as valuable, if not more valuable, than the models themselves. Being able to embed the data in a 3D PDF allows me to share it and not worry about it being modified. The easiest way to view IFC data on an object is to click on the object in the model. When you select a component, it will highlight, the model tree will expand, and you can select the node of the component.
In Figure 4, I have selected the fireplace. The model tree expanded and highlighted the node (object) I selected. The node is under IFCWALL -> FIREPLACE.
Figure 4: Selecting a component and locating it in the model tree
To see the properties of the component, choose the object to which the node belongs (one branch higher than the node). All the IFC data will display in the properties window on the lower left side of the PDF. Select the FIREPLACE and the IFC data for the selected object will appear in the properties window.
In this example, the properties displayed are the default Revit properties. Any parameters you create, be they project or shared, will export with the model and be visible in the PDF.
Using 3D PDFs in your practice
If you are working with clients who have Revit, the best option for sharing your models is in Revit; however, 3D PDFs can still be valuable to your practice as a marketing tool. At my firm, our project sheets contain all the information on a specific project as well as a few photos. With a 3D PDF we can include the same information and the building in 3D for the prospective client to view.
Figure 5: Properties for the fireplace selected in the model
On projects that have not been built, we have the model that created our construction drawing set. Insert that model in to a PDF and now we have a representation of the building to accompany the 2D rendered images. For product manufacturers, the ability to embed a 3D model of their product into a specifications sheet allows clients to have a better understanding of the product. The architect can “play” with the product prior to receiving a sample. The more information we provide to our clients, the more informed their decisions.
I use Revit in my work as an educational facility planner because it simplifies my workflow, guarantees that changes I make in a schedule are reflected in the plans, and allows me to work smarter. My clients are learning that these models also have value to them because they do not have Revit nor the expertise to use it. By importing my Revit models into a 3D PDF, I am able to give my clients a 3D model and the data it contains. Slowly, I am exposing them to the value of BIM in managing their facilities.
A 3D PDF is also a powerful marketing tool. Firms can include a complete model in their project sheets. For product manufactures, clients can “play” with the products. The more information we can convey to prospective clients, the greater the probability they become clients. There are other IFC viewers, but none are as widely used as Acrobat Reader. We create massive amounts of data on a daily basis. Let’s put it to use.