AECbytes Tips and Tricks Issue #63 (October 16,, 2012)

Tracing Graphic Images in Revit’s Family Editor

Michael Anonuevo
Autodesk Revit Architecture Certified Professional and Author

In Revit’s Family Editor, graphic images can be traced to create simple to complex shapes. These shapes can be in the form of Extrusions or Split Face regions that are used to embellish components with architectural ornaments, signage, logos, graphic designs, etc. A graphic image can also be used as a scale reference. For example, when only basic dimensions and a 2D image (e.g., plan, elevation) are available for a furniture component being replicated, the image can be imported into the Family Editor and used as a visual reference. In a 2D view, the image can be scaled so that one of its dimensioned parts coincides with sketched reference planes having the same dimension. Thereafter, all other parts with missing dimensions can be determined using the resized image. This article explains the methods in preparing an image for tracing, how to trace an image, and how to scale an image to a specific size.

Two Methods of Importing Images

Images can be brought into the Family Editor by clicking the Image button (Insert > Import). Every time this button is clicked, a Revit message pops up.



This is a reminder to delete the imported image before loading the family to a project for improved performance and smaller file size. After clicking the Close button, the image is displayed with an invisible bounding box attached to the cursor, indicated by a dashed X-mark with four drag controls at the corners.

Images can also be dragged and dropped from a folder into the Revit window. In this method, no pop-up message appears. In the drawing area, the image is displayed with the cursor as shown above. After clicking at a desired location, the image is placed. When any of the drag controls is clicked and the mouse is held down and moved, the image resizes but maintains its proportion, as shown below. There is no need to press the Shift key.

Note: To prevent the graphic image from being moved, select it and then click the Pin tool from the Modify panel of the contextual tab.

Imported images can be in any of the following formats: BMP, JPEG, PNG, or TIFF.

Preparing an Image for Tracing

Anything drawn in sketch mode appears in magenta. Therefore, an efficient way to trace a colored or black and gray image is to modify its opacity, as shown below, in an image editing software such as Photoshop.



Black and gray images can remain as is or lightened. Regardless of the image's color, try to sharpen the image. Get rid of unnecessary artifacts or background to make the edges clearly distinguishable. Resolution wise, the higher the number, the better it is for tracing.  In low resolution images, the edges appear pixelated when zoomed in. As much as possible, importing an image with the correct scale is preferable. Otherwise, the image can also be resized.

Editing the appearance of an image is a subjective matter and depends on how a user perceives the magenta lines in sketch mode, against the color of an image overlay. In the left illustration below, the magenta lines are hard to perceive over an unretouched image of a plant ornament. But a lightened grayscale version of the image, shown on the right, is much easier to trace

After tracing the plant ornament and clicking Finish Edit Mode, the extrusion is created.

To fill the openings, copy the component and paste it at the same location (Paste > Aligned to Same Place). This places the component on top of the original. While it remains selected, click the Edit Extrusion button on the Modify tab of the ribbon (Extrusion > Mode). In sketch mode, delete the border.



After clicking Finish Edit Mode, the resulting component fills the openings (see left image below) which can later be assigned with a different material (as shown in right image below).

Using the Draw Tools in Sketch Mode to Trace an Image

In sketch mode, the Draw panel contains all the necessary tools for tracing complex curved shapes. The key to using these tools efficiently is to know how they behave. Only three draw tools were used to sketch the plant ornament—the Line, Start-End-Radius Arc and Tangent End Arc tools. The Line tool is used for sketching straight lines and also serves as a point where the Tangent End Arc tool connects from. The Start-End-Radius Arc tool creates arcs. The Tangent End Arc tool is used to connect tangent curves emanating from lines or arcs. Here are a few pointers when tracing an image:

  • Draw tools can be used continuously as long as the Chain box on the Options bar is selected.
  • All snaps are On by default. There are situations, however, when the cursor is pulled to a snap point when it is in close proximity to a previously sketched segment. When this happens, type SO (snap off). This temporarily turns Off all snaps. After a click is made, the snaps are automatically turned back on.
  • The Tangent End Arc tool is the only Draw tool that cannot be used as the first segment in sketch mode. It needs an arc or a line to attach to.
  • As much as possible, sketch a closed-loop profile continuously from the starting point to the last point.
  • If you make a mistake while sketching a segment, you don’t have to exit the tool to select and delete that segment. Just press Ctrl + Z (Undo) or click the Undo button from the Quick Access Toolbar. The sketched segment reverts back to its previous state and the current tool remains active.
  • You can switch to another tool without exiting the current tool by going up to the Draw panel and selecting a new tool.
  • Extrusions can have more than one closed-loop profile. However, they must not overlap.
  • The smallest segment that can be sketched is around 1/32”.
  • Try to create as few segments as possible to create a complex shape.

Using the Split-Face and Extrusion Tools

Depending on their intended use, both of these tools are useful in creating graphic elements such as ornaments, logos, and signage. If you need simple ornaments to embellish a part of a component, the Split Face tool is ideal for that purpose (see the figure on the left below). If you need to assign a material parameter for the graphic element and the background, then the Extrusion tool is the way to go (as shown in the figure on the right).



Split Face regions cannot be assigned with a material parameter. You also have to remember that only one closed-loop profile can be created using this tool. To create an opening inside the boundary of an existing Split Face region, select the region with the Split Face tool. This automatically turns the interface into a sketch mode where a single closed-loop can be sketched. After clicking Finish Edit Mode, the newly created region cuts the surface of the existing region and exposes the finish underneath. All these three steps are illustrated below.

Profiles created from the Split Face tool can be copied and used as profiles for extrusions or vice versa. The figure on the left in the image below shows a Split-Face profile of a dragon in Edit mode. To use the profile in an extrusion, copy the profile to the clipboard (Ctrl + C) then click Finish Edit Mode. Select the extrusion where the dragon's profile is going to be copied to, and then click the Edit Extrusion button on the Modify tab of the ribbon (Extrusion > Mode). In sketch mode, paste the copied profile (Ctrl + V). While in sketch mode, the pasted profile can be resized, flipped, rotated or modified. In the illustration on the right shown below, the dragon profile was resized and placed at the center of an extrusion boundary.

After clicking Finish Edit Mode, the result is an extrusion with an opening the shape of the dragon, as shown on the left below. Using the method previously explained, the opening can be filled with an extrusion with the same exact profile, as shown on the right.



These two extrusions can further be modified with a void that alters their top parts, as shown below. Material parameters can also be assigned to both extrusions.


How to Scale an Image to a Specific Size

Let’s say that a graphic image of a scroll is imported in a face based template where it is going to be traced. The image has to be resized proportionally so that the side edges of the scroll (shown pointed with arrows in the figure below) fits the highlighted 5 feet width area of a rectangular extrusion.



To resize the image, select it and click the Scale tool from the Modify panel (Modify > Raster Image). Instead of the scale cursor, the cursor turns into an arrow cursor with a crosshair cursor below it.



Position and click the cursor at the left edge of the graphic scroll, then move the mouse to the right. A temporary dimension appears and updates as the mouse is moved. Next, position and click the cursor at the right edge of the scroll.



After the second click, the cursor turns into the scale cursor, as shown below.



A temporary dimension appears where a value of 5 feet can be typed without selecting the dimension.



This scales down the image. When positioned at the center of the extrusion, the edges of the scroll matches the 5’ width of the sketched reference planes, as shown below.


Conclusion

Creating extrusions or split face regions based on traced images is an effective way of adding embellishments to family components. Knowing how a Draw tool behaves makes tracing and sketching complex shapes easy. Imported images can also be used as backgrounds. In the Material Editor, custom bumps, reliefs, cutouts and procedural maps can be created using imported images. In a project, images can be used as decals to represent signage, wall paintings, murals, wall covers and other decorative graphic elements.

More Tips, Tricks, and Techniques

Michael has written the following PDF eBooks available for purchase at his website:

  • Creating Custom Revit Architecture 2013 Families, 777 pages, over 2000 images
  • Creating Custom Revit Architecture 2012 Families, 751 pages, over 2000 images


A 163-page PDF sampler containing the full table of contents and sample images from these two eBooks can be downloaded from the following link:
http://www.littledetailscount.com/documents/ebookpromo.pdf

These eBooks contain hundreds of tips, tricks and techniques. Each eBook teaches the efficient ways to create families and explains the subtle little details that go with family creation which no other books explain. A major feature is Chapter 16, which reveals the secrets behind the creation of the families at his website. Metric editions of these two versions will be available on or before October 2012.

 

About the Author

Michael Anonuevo is a published author, BIM modeler, and musician who owns and runs www.littledetailscount.com. His website specializes in unique and highly detailed Revit families created in native Autodesk Revit Architecture geometry.

Michael is also an Autodesk Revit Architecture Certified Professional. At ClubRevit.com, he regularly writes articles pertaining to Revit families. He also writes product reviews and is a contributing author at AUGIWorld.

 

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