Join Paul F. Aubin for an in-depth discussion in this video Fine detail abacus, part of HBIM: Historic Building Re-creation.
- So let's start digging into our fine detail version of our capital. You may recall that the capital is actually made up of several nested families, and one of the first ones we looked at in the medium detail version was the one that I'm illustrating on screen here. This was the abacus and the bell. So the bell was just a simple cylindrical form here, and the abacus was just this simple extrusion at the top with the wedge-shaped sides. Now, switching over to Revit, I've created a starting file here for our fine detail version, and you'll notice that the sides are now using these curves.
So that makes them a little bit more detailed and a little bit more appropriate for our fine detail representation. Now what I want to do here, is you may recall in the medium detail version, that we talked about this rig here, this collection of reference lines that was used to drive the shape of this form. And I've copied that rig off to the side, so that we can dig into it a little bit more detailed. And what I want to do in specific is, I want to create the missing arc. So you can see I've only got three arcs right now, I want to add the fourth one in here. And so to do that, we can dig a little deeper into some of the features of this whole rig approach.
So, the key is to use a Reference Line, and more importantly, to use the Reference Line with 3D Snapping. 3D Snapping is a very powerful feature that allows us to, of course, snap to things in 3D, as its name implies, but, if we're using this option here, which should turn on by default, this Draw on Face option, then it also creates relationships and connections between the various parts and pieces, so, what we want to do here, is make sure that this is on, make sure 3D snapping is on, and then notice that you're able to highlight one of the existing reference lines.
So I'm going to click right on this one, and then come across and click on that one. And I'll cancel out of the command. Now I deliberately drew it at a angle there, just to kind of show you the way this works. Notice that you can select one of those points now, and a couple things, you're going to see a small little plane going through that point, and, if you look at is over on the Properties palette, it will have this Normalized Curve Parameter. Now, we talked about that in the previous movie, but if you want, you can manipulate this, and change the value, and notice that that actually drives the location of the Associated Reference Line.
And so that's really the key, that's what we're looking for, is that as these points move around, they're changing the shape of this Reference Line. So, I need one more thing for my rig. I still have to locate where this midpoint is. So all I need to do, is click the Point Element, and once again, make sure that Draw on Face is turned on, it should by default, but that's a really important aspect of this, and this time, I want to click right on this line, but specifically, exactly at the midpoint. Now when you do that, sometimes it doesn't show up right away, so, if you just pan the screen it will make it appear.
Cancel out of the command, and you should now have a point right there, that point, when you look at the properties, should be at exactly 0.5. And we're going to leave it there. So all that means now, is, if you come back and take this point, and drag it, not only is it changing the shape of the overall line, but notice that it keeps moving that point, but that point there remains at the midpoint. And so that's really the key, is we're building this rig that's a connection of pieces. So the overall rectangle that was already here, is being driven by these two parameters.
And then, when those parameters flex, it changes the locations of these two reference points. When those points flex, it changes the length of the line. And when the line's length or angle changes, it changes the location of this reference point. So it's the hip bone connected to the knee bone, knee bone connected to the shin bone, and so on. Right, so you're kind of getting all of these interconnected relationships that will drive everything without the need for a bunch of extra parameters. I do need one parameter, I need a parameter to say how far off the corners I want these Reference Points to be placed.
Now, I've already got that parameter. If we look over here, at one of the existing points, scroll down, it's currently at 9.78, and, it's actually using Segment Length. So, what we need to do is actually two things here, I need to take these two points, and I'm just going to hold my Ctrl key down, and select both points, it should say Reference Points (2) here. And if it says anything other than Reference Points, then you want to try and select again. So it needs to say Reference Points. And, when we scroll down, it's currently set to Normalized Curve Parameter.
Which, if you recall, is a value between zero and one. So it's sort of a percentage along the length of the line. Well, we want to change that to Segment Length, so that we can set the distance in units, instead. So, I'll set it directly in units, and then, maybe try a value of about 18. Okay, now I'm just making up a number here, but, notice what happened. This one is measuring 18 from this corner, this one is measuring 18 from this corner. So we're almost there, but we want them both to measure from the same side.
So, I'm going to select only this point, and then scroll down here, and instead of measuring from the beginning, I'm going to measure from the end. And then when I change this to 18, notice that it now snaps to the other end. So now, I'll select both points again, and I don't really want it at 18, I want it at that 9.78, right? Well I've already got a parameter for that, so instead of setting 9.78 here, I'll just click in this Associate Family Parameter button, and choose the parameter that I've called Abacus Midpoint.
And the reason I called it Abacus Midpoint, is because ultimately this line, is setting where the midpoint of this curve is, so that's why I named it that. But anyway, you can see that it moves, and sets this to 9.78, or whatever that value was. So now I'm ready to draw my arc. Now your arc is also going to be a Reference Line. So I'm going to click Reference Line, and I want the Start-End Radius Arc. Now the Start-End Radius Arc also can use 3D Snapping, which is really powerful, because if you pick your points, so you now have an arc, that has these Reference Points that control the shape of the arc.
Now here's the thing that's a little counter intuitive about this. Let me delete this one. Go back to here, Start-End Radius Arc. Turn on 3D Snapping, make sure that this Draw on Face is turned on. If you click on an existing point, so just put your mouse right over that existing point, up at the top there. If it doesn't highlight and say point, you can type SX on your keyboard to force it to snap to that point, but it should find it on its own. When you click that point, it won't draw a new point, it will inherit the one that's already there.
So I'm going to come down here and pick this one, not this one, but this one, right here. That's my end point, and then, finally, this one is going to be the midpoint of that arc. And click it again. And if I cancel the command, do a little window selection around one of those points, notice there's only one point there. Notice there's only one point here. So when you click directly on that point with 3D Snapping, Revit is smart enough to just assume the existing point and not create another one in the same spot.
So now you should have a nice chain here, and if I highlight, you'll see that it highlights all the curves and there's actually four little straight lines in there, as well, so when you click, it should select eight elements. So over here, it should say Reference Lines (8). If it says anything else, then you want to double-check your selection. And with that selected, you can click the Create Form button and it will suggest either a Solid or a Plane. Now, I'll click Solid there, and it extrudes it up. But you may recall that our column capital actually is built down, so what I can do, is come over here on the Properties palette, and the bottom, I want actually at 11 and a half parts, or 11 and a half units below, and the top I don't want to go up at all, so I want to set that to zero.
So when I just set those two numbers there, and apply it, you'll see it pop down to the correct location, just like it is over here. Now, to finish this up, the molding is not actually just squared off like this, it actually has a nice set of molding curves that uses some OG Profiles and so on, so, it turns out that I've already placed a separate family here in the file. Now, one of the things you need to know about the Masking Environment is we can do things that are, basically just like Sweeps, but you can't use a Profile to drive a Sweep in the Masking Environment.
Everything that you build in the Masking Environment has to be 3D geometry, or it has to use model lines, or Reference Lines. So, the way to work around that, is you can actually just create a Generic Model Family, in the Traditional Family Editor, and draw model lines in that family. And that's what I have right here, so I'm going to select this family, and click Edit Family. And that's just going to take me to the Traditional Masking Environment. This is a face-based family, so it's got a generic face here. And if we look at it in Plan View, you know, it looks a little bit complicated, but, there's a couple curves here that are being driven by some formulas, and there's a little bit of trigonometry in here to make all these curves work correctly.
We have a course here, in the library, called Family Curves and Formulas, and I detail in there exactly how to create this kind of curvature, and where to get that center point exactly, and how to set that formula. So if you want to learn more about how this was approached, you can watch that course, or watch the movies on creating OG Curves in that course. But meanwhile, I've got this file already here and ready to go, so let me just close it, I'm not going to save it. And all we have to do, to create 3D Form from this, is come back and select our same chain of Reference Lines.
That chain of Reference Lines, it should say Reference Lines (8) again, it's the four arcs and the four little short lines, that's going to be the path of our Sweep. Then we're going to hold down the Ctrl Key, and click this Generic Model. That's going to be our Profile. So in the Masking Environment, you always select your geometry first, and then you just click Create Form. And you can see there's only that single Create Form button there. Now the way this is going to work is, Revit will be smart enough to figure out that you've got a Profile, or a Generic Model in this case, perpendicular to the path, so it will assume that you want a swept form.
Now, I could do a Solid Sweep, but actually, in this case, what I want to do is create a Void Form. And, when I do that, you see it will take this shape that we have, and treat it almost like a router bit, and it goes around and it kind of carves that away from the entire molding. And you can see the final result looks like that. Now if you put your mouse over here, and you kind of Tab a few times, you can get that 3D form, and you can see that that's the Void Form, right there that it created. If I isolate that, right, you can see what that looks like.
So it just swept that shape all the way around. And let me just reset the Isolate there. And that's the final version of our fine detail abacus and bell.
- Researching source materials and source drawings
- Sketching and modeling architecture
- Setting up the project in Revit
- Modeling overall forms
- Using system families
- Adding details such as columns and moldings
- Creating an interior model
- Rendering the project