Creating Complex Family Shapes in Revit : Introduction
June 7th, 2010 | Author: Michael Anonuevo
In 3D modeling, there is more than one way to accomplish certain tasks. Although the fastest procedure is the obvious way to go, the choice is up to the modeler. Depending on what is being modeled, you can choose solid or void forms (extrusions, revolves, blends or sweeps) or any combination of these forms to create the same shape. Your main goal is to choose the most efficient method to save time and avoid problems that may crop up later.
I’d like to begin my first post in Revit family creation by examining the free LDC (Little Details Count) Revit family download available from my website at: http://littledetailscount.com/index.php/products/free-revit-family-download-beer-mug-dining. I’m referring to the Beer Mug family which is also available from RevitCity.com.
This post will consist of two parts. Part-1 is intended for experienced users who just want to quickly browse and find out how the model was created. Part-2 is a step-by-step procedure with detailed explanation on how the model was created.
Before I proceed, here is the format and order that I’ll follow to explain this family and other families in my future postings:
- Presentation of a Revit rendering of the object to examined
- Analysis of the object to be modeled
- Revit family tools and modifiers to be used
- Step by step procedure in creating the family
- Architectural building applications
Note: For beginners or for anybody new in Revit family creation, you may want to familiarize yourselves with the Revit family editor tools, in particular, the Form creation tools (Revit Architecture 2010). I’ll go over them briefly as I go through the modeling process but it is up to you to study how they work. Autodesk has a whole bunch of documentation including “Families Guide Imperial Training Files” that you can download at http://usa.autodesk.com/adsk/servlet/index?id=13080413&siteID=123112&linkID=9243097. There are also numerous internet blogs, tutorials, articles and instructional books that deals with this subject. It will be a lot easier for you to learn modeling methods on this blog if you have a basic understanding of the Revit family editor tools.
Revit Family: Beer Mug
Figure 1 shows a Revit rendering of the LDC beer mug including Shading with Edges view and a Wireframe view.
In a nutshell, here is how the mug was created (Figure 1a):
Modeling tools & Modifiers:
The mug body is a simple solid revolve with corners that were rounded using the fillet arc tool. The mug handle is a solid sweep with a profile whose corners were rounded with the fillet arc tool. The rounded rectangular depressions were created with Void revolves (see Part 2, Step 3, Figure 9) and radially arrayed 8 times around the perimeter of the glass. The diamond shaped depressions were created using the Void blend form creation tool (see Part 2, Step 7). It was then radially arrayed 24 times around the perimeter of the glass. These 24 voids were then duplicated two times below the original to form 3 rows of diamond shaped depressions near the bottom of the glass.
Mental Ray Materials:
Mug body and handle: Glass Clear using the default settings
Beer: Lager Dark – Glass Dark Red Frosted with color that was modified; Lager Light – Glass Amber with color that was modified
Dimensions: Level of beer
Materials and finishes : Type of glass and type of beer
Visibility settings : show or hide beer
Here is a step-by-step procedure on how this beer mug was created.
If this was a plain mug, you can easily figure out what modeling tools to use. However, you’ll probably be taken aback by the diamond and rounded rectangle patterns depressed on the mug. For this family, we are going to use the following tools and modifiers:
a. Solid revolve
b. Solid sweep
c. Void Revolve
d. Void Blend
e. Fillet Arc
f. Trim tool
1. Begin by creating a new family. Open a Generic Model Face based.rft template (Figure 2). I favor a Face based family because of its flexibility in attaching to any surface. You can also rehost it to any surface anytime.
2. Open the Front elevation view and sketch your Reference planes as shown in Figure 2a:
3. Now go to Create tab > Forms panel. Click Solid drop-down > Revolve as shown in Figure 3:
This takes you to the Sketch mode. Draw the revolve polygon (magenta color) as shown Figure 4.
Choose the Fillet Arc tool (see Figure 5) from the Edit Revolve tab>Draw Panel and make sure the Radius box is checked. Enter 1/32” radius and do a Fillet on both sides of the beer mug top part. Do the same for the bottom part of the mug.
Note: A great way to enhance a model is to make an impression of the smooth edges of an object. Most often, modelers tend to ignore this technique thereby creating a sharp and boxy representation of the object. However, Revit has a limitation as far as how small you can sketch. Depending on the object, 1/32” is probably the smallest line or radius you can draw in sketch mode.
The best way to model precisely is to have to have the object in front of you to measure (or without it, a cut sheet or reference sheet with accurate dimensions). Although it’s possible to create a 100% accurate model, it may not be necessary to do so as an impression or simulation of the object may suffice. Also, we just want to model the parts that can be seen by the eye.
When you’re finish sketching, click Finish Revolve (Figure 6):
If for some reason, you didn’t close the polygon or you didn’t draw the object properly, Revit will display a message such as this (Figure 7):
This is how your model should look like in the default 3D view after clicking Finish Revolve (Figure :
3. For the rounded rectangle depressions in the glass, I chose the Void Revolve form so I can have a depression with concaved top and bottom inner corners. This is a trial and error procedure to get the right horizontal width of the depression which can be adjusted by varying the radius of the Revolve. Draw the revolve as shown on Figure 9:
After clicking Finish Revolve, you’ll get these results (Figure 10):
4. If for some reason, the Void revolve form did not subtract from the mug, go to Modify tab>Edit Geometry panel then click Cut dropdown>Cut Geometry as shown below (Figure 11):
The cursor changes its appearance (see Figure 12) and waiting for you to click the objects which you want subtracted from each other (the order does not matter).
5. Go to plan view and select the Void revolve you just created. If it’s difficult to select the Void, then open the default 3D view and tile the windows (just the plan view and the 3D view). Select the Void form from the 3D view then click on the window bar of the plan view (not inside the view window, or else you’ll deselect the void form!). The next step is to duplicate this Void revolve 8 times around the perimeter of the glass. We use the Radial array tool for this procedure with the option bar settings as shown in Figure 13:
Note that the rotate icon’s location (Figure 14) defaults to the center of the object being arrayed. We want to drag this icon to the middle of the beer mug which is the intersection of Center (Left/Right) and Center (Front/Back).
After you drag the rotate icon and release it to its new location, the array command is still active and now waiting for you to specify where the starting point of the rotation is. It could be anywhere but for this example, let’s click the Reference plane to the left of the rotate icon as shown on Figure 15.
After clicking on the starting point of the rotation, the array command is still active and now waiting for you to specify the angle of rotation. For angle reference, we will rely on the temporary dimensions that appear whenever you rotate an object (see Figure 16). Dividing 360 degrees by 8 (the number of voids we need), we get 45 degrees. Move your mouse clockwise till you see the temporary dimension change to 45 degrees then click.
After the array procedure, the mug reappears with the Void revolves in place and subtracted from the surface as shown in Figure 17:
If you select all the objects (on plan view), this is what you’ll see (Figure 18):
…and in the default 3D view, this is how the mug will look like (Figure 19):
6. Before we add the diamond shaped depressions, let’s do the mug handle first.
We’ll be using Solid Sweep to create the handle. A sweep is similar to an extrusion but you have to draw a path for a profile to follow. Go to Front elevation and click on Create tab>Forms panel. Click Solid drop down>Sweep. You’re now in Sketch mode where you’ll click on Sketch Path. Based on the Reference planes you sketched (on Figure 2a), draw the Sweep path as shown in Figure 20:
Click Finish Path then open the Right elevation. The profile is always swept perpendicular to the path you draw. Refer to Figure 21 below for the following steps: Click Select Profile in the Mode panel of the Sweep tab (A) then Click Edit Profile in the Edit panel of the Modify Profile tab (B). This will take you to the Sweep > Edit Profile tab (C) where you’ll find the sketching tools in the Draw panel.
Sketch the profile as shown in Figure 22:
Click Finish Sweep then go to the default 3D view. Your mug should now look like this (Figure 23):
7. Let’s now move on to the diamond shaped depressions on the mug. This can be a little trickier than the rounded rectangles although they are both Void forms. For the diamond shape, I chose a Void blend to simulate the diamond shaped depression. A Solid or Void blend creates a form by combining two shapes on two different planes along a linear path.
On plan view, draw a Reference plane as shown in Figure 24. Click on the Element Properties and type front for the Identity Data Name:
Go to Front elevation and sketch your Reference planes based on the dimensions shown in Figure 25:
Go to Create tab>Forms panel. Click Void drop-down>Blend as shown in Figure 26:
You’re taken into sketch mode where the first shape you have to draw is the Base. On the options bar, enter 3/32” for depth. On the Create tab>Work Plane panel, click Set. On the dialog box that pops out, scroll down till you find name front under ‘Specify a new Work Plan’. This is the plane we’re going to be working on which you just created on plan view. Draw the shape according to the reference plane dimensions shown on Figure 25. You’ll notice that the Finish Blend button on the far right of your screen is grayed out. That’s because you have to finish sketching the Top shape after the Base shape. The Base sketch should look like this (Figure 27):
Now click on Edit Top where you’ll sketch your Top shape as shown on Figure 28.
We’re almost done! So now, click Finish Blend on the rightmost side of the ribbon menu on your screen. The Void blend should be created and subtracted from the glass
In plan view, select the diamond shaped Void blend you just created. Refer to Step 5 and follow the procedure described in selecting Void forms. Make sure the Group and Associate box is not checked. Now instead of arraying it 8 times, we’re going to array it 24 times around the perimeter of the glass. 360 divided by 24 is 15 degrees. Do the array (don’t forget to relocate the rotate icon to the center location of the mug), click on the starting point and when it’s time to specify the angle, move the mouse clockwise and wait till the temporary dimensions says 15 degrees. Click the mouse and your Void blends should be created and subtracted from the glass.
Finally, select the 24 Void blends from the default 3D view (control-click each one, rotating the 3D view as you go). When all Voids are selected, go to Front Elevation and follow the procedure shown below. Set the option bar settings as shown (Figure 29).
That’s it! Your model should look like this (Figure 30):
There are three parameters applied to this beer mug and they are:
1. Dimensions: Level of beer
2. Materials and finishes : Type of glass and type of beer
3. Visibility settings : Show or hide beer
Dimensions parameter (level of beer):
Open the Front elevation. Make sure your work plane is set to Center (Front/Back). Click Create tab>Forms panel. Click Solid drop-down>Revolve (Note: a Solid extrusion is another way of accomplishing this step. But since the Front elevation already has the Reference planes we need, it is as easy to do the Revolve).
Select the pick line tool and click on top of the Reference planes shown in Figure 31:
Next, trim your lines and draw the axis line (Figure 32):
We now have the Solid revolve (beer content) which we’ll assign a parameter. Dimension the level of beer as shown (Figure 33):
Make sure the dimension is selected and go to Label drop down <Add parameter> as shown on Figure 34:
After scrolling down to <Add parameter>, you’ll get the dialog box shown on Figure 35. Apply the settings indicated:
Now let’s test the parameter. Click Types and do steps shown on Figure 36:
Material and Finishes Parameters
1. Look at Figure 37 below. Click on Types (A) then click Add (B) to get the Parameters Properties (C). Apply the settings indicated then click OK. Type of Glass is our first Materials and Finishes parameter.
2. Repeat the same procedure for ‘Type of Beer’ (name it ‘Type of Beer’). This will be the second Materials and Finishes parameter.
3. We now have two Materials and Finishes parameters that we will associate with the beer mug. But before we do that, click Types again from the Families Properties panel. We want to specify values for the Materials and finishes (see Figure 38).
When you click the right side of the Value field (shown shaded with yellow above) right next to Type of Glass field, the Materials dialog box pops out (Figure 39):
Select Default and click on the Duplicate button. Name the material: Glass_Clear. Click on the Render Appearance tab then click Replace… You’ll be taken to the Render Appearance Library where you’ll see Class: on the upper left corner. Click the drop down menu next to it and select Glass. You’ll be presented with all sorts of glass types. Choose Glass Clear. Click OK a couple of times to get back to the Family Types dialog box.
We now want to specify the material for Type of Beer (two types: dark and light). Click on the right side of the Value field next to Type of Beer field to get to the Materials dialog box again. Select Default and click on the duplicate button and name it Lager_Dark.
Note: There is no such thing as Beer material in the Render Appearance Library (at least, not on this version!). Getting a specific finish is accomplished by choosing the specific material listed in the Render Appearance Library. If the material is not on the list, then choose the material with appearance closest to the one you want. Duplicate and rename the material then change its properties, colors, scale, etc.
Click on the Render Appearance tab then click Replace… You’ll be taken to the Render Appearance Library where you’ll see Class: on the upper left corner. Click the drop down menu next to it and select Glass. Choose Glass Dark Red Frosted and on the Solid Glass Properties, change the Custom Color to Single Color with RGB values of 112-024-020. Click OK two times. Click Default again and click on the Duplicate button and name it Lager_Light. Click on the Render Appearance tab then click Replace… You’ll be taken to the Render Appearance Library again where you’ll see Class: on the upper left corner. Click the drop down menu next to it and select Glass. This time, choose Glass Amber on the list of glasses. On the Solid Glass Properties, change the Custom Color to Single Color with RGB values of 229-191-000. We now have two types of beer to choose from.
Associating the parameters with the materials:
1. Select the mug cylinder (body) and the mug handle then click the Element Properties icon to get the Instance Properties dialog box (A). Click the little button on the right side of Material row to get the Associate Family Parameter dialog box (B). Here, select Type of Glass and click OK (Figure 40):
After you click OK, note the change below (Figure 41):
The mug and mug handle we selected are now associated with the Type of Glass Material parameter. After you click OK on the Instance Properties, your glass will look like this (Figure 42):
2. Let’s repeat the previous procedure and select the Beer Content (solid revolve). Click the Element Properties icon to get the Instance Properties dialog box. Click the little button on the right side of Material row (see Figure 40) to get the Associate Family Parameter dialog box. Here, select Type of Beer and click OK. The mug will now appear like this (Figure 43):
Visibility Settings (show or hide beer content):
Click on Types from the Family Properties panel then click Add under Parameters (right side of dialog box). Apply the settings shown on Figure 44 then click OK.
A new parameter (Show Beer) under Graphics has been added (Figure 45):
Notice the box to the right of Show Beer is checked by default. In the Graphics category, the Yes/No parameter type acts like an on and off visibility switch. When the box is checked, the associated component shows up, when it is unchecked, the associated component is hidden.
Note: the box can be left unchecked too if you didn’t want the beer content to show when people start using your family. But for this exercise, let’s leave it checked.
To associate the beer content to the Visibility settings (show beer), select the beer content then click the Element Properties icon to get the Instance Properties dialog box. Click the little button on the right side of the Visible row to get the Associate Family Parameter dialog box. Here, choose Show Beer then click OK a couple of times. The beer content is now associated with the Show Beer visibility parameter.
Testing your Family inside a Project
So now the fun begins when you start using your family! Go open a new project then switch windows so you’re back to the beer mug family you just created. In the Family Editor panel, click Load into Project (Figure 46):
Your family will be loaded to the new project you just created and you’re taken to your Level 1 (this could be different depending on the way you setup your project template) where the Beer mug is all set for placement. On the Placement panel, Revit defaults to Place on Vertical Face. What you want to do is click on Place on Work Plane. Click anywhere in the middle of your screen to place your family then click the Escape key a couple of times. Select the Beer mug again then click Element Properties (A) to get to the Instance Properties dialog box (B) as shown in Figure 47.
For anybody using your family, they will be presented with all the options above (C, D, E, F,) which you created in your family. This is one of the powers of Revit, the ability of users to customize families for their own purposes!
Architectural Building Applications
You can derive a lot of simple or intricate families based on this simple exercise. With a little creativity, you can combine the Form modeling tools to create your own unique families. From one of a kind custom vases to unique counters, kiosks, curtain wall panels, grand ceilings etc., the possibilities are endless.
Here is a piece of furniture I created from known dimensions, photographs and historical information from the internet. It’s Frank Lloyd Wright’s exquisite Barrel Chair (Figure 48).
This piece of furniture presents seemingly modeling challenges that may discourage you from attempting to replicate it. But if you look at it closely, you’ll find that I’ve used basic Solid and Void forms just like I did with the beer mug. Let’s examine this briefly:
Tip: If you open any of your Revit families and select a single component in it, Revit will give you clues as to what form modeling tool was used, thus helping you examine the particular family. For example, if you select the back seat of this chair, a new tab (Modify Sweep) will be added to the menu corresponding to the tool being used (Figure 49):
Here are the form modeling tools used for this chair (Figure 50):
In creating complex Revit family shapes, good modeling skills is a requirement that takes time to acquire. You need patience, perseverance and an analytical mind to figure out the best combination of tools to accomplish your unique modeling tasks. If you don’t practice, it will be difficult to execute complex shapes in Revit. Although I can impart a lot of modeling techniques, there are a lot of little nuances and subtle ways that is hard to explain in the way Revit reacts depending on how you select, move or combine different tools. It is very hard to document them because they occur randomly. Unless you’re training with me and I can see what you’re doing, you’re the only one who will notice these things. Everyone has their own ways of executing certain procedure or movements. Revit will react positively or negatively to your mouse movements and gestures. It is only by practicing diligently and using tools repeatedly that you’re able to master certain techniques. I urge you to not be afraid to experiment and not be hampered by rules. Thank you for your patience.
If you haven’t done so, you can download the Beer mug family from my website for free. By doing so, you’ll get another free family download to complement the mug. You can also download the Beer mug family and Barrel chair family from Revitcity.com.
For those who previously downloaded the Beer mug from my website, there’s a new version available (June 2010). Please log in to your account and download it.