REVIT ROTATION RIGS THAT DO NOT USE THE ANGLUAR DIMENSION
What if I said the following, “you will never need to use the angular dimension again when creating rotation parameters in families” would you believe me?
I have found two alternative methods to create rotation parameters that do not use the angular dimension. Why did I create these two methods? The answer is simple, the need for stability.
The traditional method, shown in the rig above, uses the angular dimension command. It is not a secret that it is unstable when it is at a zero value and breaks most of the time at other angles. Because of this, I have created two methods that completely avoid this unstable dimension. It’s called “Ride the Rail” method for use in the mass and adaptive component family environment and “open reference circle” method for use in the classic family environment.
I created the “Ride the Rail” method as a solution to a challenge at the Los Angeles Revit User Group Meetingwhere members could submit Revit challenges. Read all about the history of Ride the Rail method here thanks Jay Zallan.
As shown above in the rotation rig, the Ride the Rail method does not use the angular dimension to control the angle of the hosting reference line hence it is extremely stable. It uses the power of the reference point to “ride” the “rail” of the circle or curve to control the angle. There is only one major drawback from this extremely stable method. Since it uses the power of the reference point, it is only able to be used in the mass family environment or the adaptive component family environment because all other environments do not have reference points. This was very troubling to me and so I decided to create a rotation rig/method that could be used in any family, classic, mass, and project environment.
I realized that the whole concept of ride the rail method was based not on the point but the reference plane of the point. I then made the connection…open up the circle and host the reference line on the reference plane at the end of the open reference circle.
From this, I created the “open reference circle” rotation method as shown in the rotation rig above and notice that it uses the arc angle of the open circle to control the angle NOT the angle parameter. Below is a step by step process on how to create the open reference circle rig to control rotation for a door family in Revit. Of course this method could be used to a rig that could then be used to rotate anything.
1. First start a new door family from the default family template in Revit. Go to the reference plan view.
2. Create a reference circle whose center is set away from the center of rotation
3. Turn on the center of the circle mark. Developers please turn it on by default.
4. Align and lock the center of the circle mark to the horizontal reference plane
5. Align and lock the center of the circle mark to the vertical reference plane
6. Note that in the step above the circle center was placed away from the center of rotation so that it would be easy to confirm that it was aligned in the correct location
7. Split the circle with the split tool
8. Delete the portion of the circle to create an “arc”
9. Align and lock the tail end of the open circle to the horizontal axis
10. Select the open circle.
11. Note that when the open circle/arc is selected a very very very interesting element pops up that is not available anywhere else in Revit…..the arc degree dimension! It is this phenomenon that I took advantage of in order for the open reference circle method to work.
12. Select the arc angle dimension and make it permanent
13. Please note that the arc angle is NOT the arc length
14. As shown above, do not get the arc angle and arc length confused. They are two completely difference dimensions. The difference is that the arc angle is able to be converted to a parameter that is CHANGEABLE. In contrast to the arch length, the arch length is a reporting parameter only, meaning it is only able to “show” the length value and not able to be changed.
15. Create two angle parameters
a. Create an angle parameter called “INPUT_ANGLE”
i. This will be used as the input angle, what is traditionally used to define how “open” a door is.
ii. I like to use the arc angle to control the back side of the angle instead of the front because it is easier to work with
b. Create another angle parameter called “ANGLE_180_FIX”
i. it is the true arc angle
ii. Give it a formula = 180-INPUT_ANGLE
16. Assign the “ANGLE_180_FIX” parameter to the arc angle parameter
17. Make the radius of the open circle a permanent dimension
a. This is done to further constrain the open circle
b. It is also very critical that it is done at this step and not any other time.
18. Set the work plane to the end of the open circle, this is done so that the reference line that will host the door geometry is placed at the correct plane.
19. Draw a reference line on the set work plane from the open circle end to the center of rotation of the open circle.
20. Congratulations! The open reference circle rotation rig is now complete.
21. Set the reference plane of the host reference line to receive the door geometry, create the door geometry on the hosting reference line.
22. How to create the door geometry will not be covered in this posting however, it is very simple to perform.
23. The following shows the rig in action in the door family and in the project environment.
24.The door family was covered here however; this method is applicable to host any geometry, in any family, in any environment.
Above is the example Door family at different angles that are hosted on a wall element in the project environment that is using the open reference circle rotation rig.