Revit Trigonometry Problem

[dbaldacchino]

Let's populate a file with a thousand instances of your family and then another with my version (I'll have to change the parameters to instance) and see if we can run some benchmarks. I think this could be extremely educational as sometimes "hunches" and assumptions turn out to be completely flawed!

[Alfredo Medina]

Yes, it would be very interesting to see the results of that comparison.

[captjim239126]

This is my solution (attached) . . . the joints between the arc and the lines remain tangent all the time

Alfredo, could you expand a little on how you constructed the arc. Did you use the Tangent End Arc or the Center-ends Arc tool? Did it matter if you started with the vertical leg first or the angled leg first? How did you constrain the center of the arc to the 2 reference planes, or does that happen automatically with the arc tool you chose? Do the ends of the arc automatically stay glued to the ends of the lines, or did you have to move them away, move them back, and then lock them?
Thanks

[Alfredo Medina]

Alfredo, could you expand a little on how you constructed the arc. Did you use the Tangent End Arc or the Center-ends Arc tool? Did it matter if you started with the vertical leg first or the angled leg first? How did you constrain the center of the arc to the 2 reference planes, or does that happen automatically with the arc tool you chose? Do the ends of the arc automatically stay glued to the ends of the lines, or did you have to move them away, move them back, and then lock them?
Thanks

Lots of questions. Well, since both my friends Steve Stafford and David Baldacchino wrote blog articles about this interesting thread in their blogs, I think I should write an article in my blog about my solution, too, considering that there are more questions now about this. My next article is due on September 30th. I will post a note here when the article is published.

[Alfredo Medina]

As promised, there is a new article in my blog expanding on my solution to the tangential arc challenge of this thread. Actually, it is the second part of the article, because in the first part I wrote about a similar question (Qatar Arc, by Scott Brown) posted in May at RFO. I thought it would be good to group both topics in the same article. A Youtube video will be added later to the article, as usual.

This is the link to the article in my blog:
http://planta1.com/forum/entry.php?2...adjacent-lines

[bulletproofdesign]

Hey Guys,

I saw this thread and thought I had some value to add.

I encountered this issue a few years back and spent some late nights frustrating myself at keeping tangents for sweeps (I was making a humble downpipe)

I tend to use trig as it stops things from breaking, however it also increases the computational overhead, and can slow larger projects down.

Attached is my geometric solution for retaining the tangential relationship. I apologise in advance if this is known info being repeated.

This solution hasn't broken on me for the last few years.

Be warned, sequence of construction is vital. Deconstructing and reconstructing may break the family so try it first.

P.S. having a circle swept, is a quick visual check for tangential as a line appears when lost.

[Alfredo Medina]

Hey Guys,

I saw this thread and thought I had some value to add.....

Thanks! It works very well, and without formulas. This thread is becoming a library of solutions for keeping things tangent in different ways.

[bulletproofdesign]

Thanks! It works very well, and without formulas. This thread is becoming a library of solutions for keeping things tangent in different ways.

No Problem

to make this kind of tangent relationship is fairly easy (omitting the numerous iterations that didn't work) if you follow the correct sequence.
1. draw your incident lines (the ones you are joining)
2. Fillet arc beteen the to at desired radius.
3. 'Show Centre' of arc.
4. Select the arc and disjoin from the incident lines by pulling pack the ends.
5. Add Radial lines from circle centre to ends of incident lines (these will be perpendicular)
6. Add and lock 90deg angluar dims between radial and incident lines.
7. Add dimension lines from incident lines to radial line ends (at arc centre) and assign as 'Radius'
8. Reconnect the arc to the incident lines.

[ThinkRevit]

All I can say is “wow”. Thanks David, Alfredo & Steve for keeping this thread alive and documenting the results on your blogs. You guys are all invaluable assets to the Revit community. Thanks again.

[dbaldacchino]

Thanks to Alfredo's nagging, I did the test and made a video that can be watched here. How awesome is that?!