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Scan Essentials Basics
Scan Essentials - Roofs

Scan Essentials - Roofs

0:02 Hey, y'all,

0:03 welcome back. In this lesson, we're going to focus on completing a few of the roofs we see in

0:09 this point cloud. And we're building this based on the work and preparation that we completed in

0:15 our previous video. All right, this tower roof will serve as a good starting point. Remember

0:23 that our overall strategy is to use the point cloud as an accurate reference, but to be

0:29 cautious about creating new geometry directly from the point cloud. Once we've established

0:36 that good starting surface, we want to favor the SketchUp geometry over the point cloud. Here's

0:43 what I mean. Looking at our tower, our outer walls are established. So in theory, the ridge

0:50 line of this roof should be directly above this center point of the wall. And for this roof, it

0:57 should also be parallel to the green axis. If we draw a reference edge, we can see that it's

1:05 really close to a lot of the scan points. And that is good, our degree of accuracy is really

1:10 high. But we don't want close, we want to keep our SketchUp model exact. So we'll continue to

1:19 draw along access directions and use good SketchUp techniques while referring to the point

1:25 cloud. So let me start again, with the tower roof, I'm going to draw an edge from this

1:33 midpoint reference, lock it in the blue direction, and then reference the point cloud

1:40 for a height. They I'll draw an edge and lock it in the green direction. For the ridge line, the

1:47 length doesn't matter at this point. Okay, we could take most any of these points that are on

1:54 this roof and draw another edge in the green direction. But I'm going to come down and focus

2:00 on this corner and create a construction point from this view, just to show how this might be

2:06 useful when we draw our edge from a different view, and then can easily reference that

2:13 construction point. Again, I'll be sure to draw my edge in the axis even though you can see that

2:22 the roof edge as built is just a tiny bit off the axis. And with that we've got two parallel

2:31 edges, so the standard Rectangle tool should work just fine to create the roof surface.

2:44 Just to show it, if I undo a few steps back to where I had just created the construction point,

2:52 I could also use the rotated rectangle at this point for the same surface. Either way, we'll

3:09 use push pull at this point to give the roof some depth, clean up our extra edges and

3:15 reference the scan to complete half our roof.

3:24 Now we can simply select all our roof geometry, make a copy and use flip along or the Scale tool

3:31 to mirror the copy and move it back into place. Based on the accurate ridge line we established

3:38 from the beginning. That leaves a bit of overlapping geometry inside this roof so I'll

3:44 select it all again, choose to intersect with selected geometry, and then erase out the extra

3:51 edges with X-ray turned on. And let's make sure to group our roof if we haven't already. Now

4:06 just to show another similar example, let's create this larger roof above the main entrance.

4:14 Toggle on the building clipping box or the hole scan if you like. This time, I'm going to simply

4:19 draw two edges from points on the roof. Make sure we toggle our snapping to favor the point

4:27 cloud and then I'll start one edge. And because we've got point clouds snapping favored, we

4:33 don't get the green inference showing up. So either toggle the scan off for a moment or with

4:41 the scan on tap the left arrow key to lock the green direction. Now any edge length should do

4:49 and let's do this again at a different point. Just making sure our edge is in the green

4:54 direction. A quick orbit can confirm that we have to edges aligned with our roof scan. Let's

5:05 toggle the scan off for a moment and draw a rectangle between our edges. Erase the extra

5:12 edges. And now you can pull some depth into the roof, and then pull the sides of the roof to the

5:19 scan points.

5:26 Or, if I back up a few steps, once we have our initial roof surface, I can right click on it,

5:34 choose align axis and then use this Scale tool to extend this surface and reference the point

5:42 cloud for distance. Either method works fine, let's just be sure to get the top Ridge as close

5:50 to our reference as possible. And we'll come back to this ridge line in a moment. Also,

5:58 remember if we changed our axis to scale this roof surface, we can quickly get our primary

6:04 axis back through the scene we created in the previous video.

6:15 There is a little bit of detail we could add at this point to the roof or we could add it later.

6:22 I'll just add this small step or soffit here before we mirror this geometry.

6:34 Okay, like the other roof. let's duplicate and mirror this half of the roof, snap it back to

6:45 the original line, intersect the geometry and clean up the results. Our roof is not finished

7:01 though, some of you will have noticed that we did not base this new roof on the midpoint of

7:08 our wall geometry. So let's be sure to do that. Make sure our roof is grouped. And then I'll

7:17 move this roof from the ridge line endpoint, lock the red direction and reference the

7:24 midpoint below. It's kind of incredible how small this move is, and speaks to the overall

7:32 accuracy of the scans. But even though this is a tiny alignment, it's so important to keep your

7:39 SketchUp geometry clean and aligned. By the way, because we've been good about aligning our

7:47 SketchUp geometry properly, it should be fairly easy now to edit our buildings group. Select

7:54 this top surface, move by this endpoint and lock it to the blue direction and match it up exactly

8:01 with the roof surface. Then, we can draw an edge from midpoint to midpoint and move that edge

8:10 straight up to exactly meet the roof we created.

8:19 And I'll do this for the tower roof as well. Now that you've seen the creation of two roofs, I'll

8:33 speed through this large roof surface using the same methods we've already seen so that we can

8:39 create these dormers on this roof. We can approach these in several ways. I'm going to use

9:06 just some construction points and basic inferencing. Using this scan, I'll place a few

9:12 construction points and really I can get away with just two since we have the roof surface as

9:19 well. One at the top corner and one at this side corner. Now I can turn the scan off and use

9:28 basic inference locking to create half of the dormer.

9:42 We'll mirror one half to complete the dormer and make this a component, since we are going to

9:49 make some copies.

9:56 I'll turn the scan back on to make a copy but I'm also gonna watch the measurements box for

10:04 what the distance shows. And it looks pretty close to 17'-4" to me, I may simply type that in

10:13 as a known measurement I can use again, that is close enough. For example, if we look at these

10:21 large bay doors below, they also seem aligned with the dormers. So I'll draw one and get it

10:30 close to the right size. And then make sure it is perfectly aligned with the dormer above. Now

10:38 I can array this shape using the dormers as a reference or by typing in 17' 4". And it is

10:46 remarkably close to the scan data. I push each of these doors back the same distance and this

10:55 model is starting to take shape. Ultimately, it's up to you and your own needs on finding the

11:03 balance between the point cloud and the SketchUp model and how many millimeters or fractions of

11:12 an inch you want to override as you build out the model. One tool that can help you keep an

11:20 eye on the model scan relationship is in the Point Cloud Manager. Under inspection, toggle on

11:29 the inspection map and vary the comparison distance. Keep an eye on the point size as well

11:37 when you view the inspection as it will have an effect on the results. All right, I think that's

11:46 enough for this lesson. Again, the most important point is just to use good SketchUp

11:53 techniques, even when referencing a highly accurate scan. Make sure your SketchUp geometry

12:01 is clean aligned and you'll get good results.