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Inference Locking

SU Fundamentals 12-1 Inference Locking

0:03 Previously, we’ve learned about basic inferencing.

0:11 You can combine axis directions and inference points and hover over points of your model to ask SketchUp for an inference to that point.

0:19 The idea of inference locking is still to move in a direction, but then to lock that direction.

0:27 Now that I’ve locked the line tool in only the Red direction, I can easily infer directly to any other point or edge in the model.

0:38 This technique is one of the most powerful abilities you can master in SketchUp.

0:46 Open the exercise file on inference locking and follow along.

0:52 There are two ways to lock an inference in SketchUp.

0:57 One is with the arrow keys on your keyboard, and the other is with the Shift key.

1:04 It’s useful to know both, but we’ll start with the arrow keys, right, left, up, and down.

1:15 Right is red.

1:17 Start drawing a line and press the right arrow key to lock the red axis.

1:26 Green is left.

1:28 Tap the left arrow key to lock the green direction.

1:32 Blue is the up arrow key.

1:37 Tapping another key will lock that direction, so I can quickly jump between locking the red, green and blue axes, or to release the lock, tap the key that is locked.

1:50 I’m currently locked in the green axis, so I’ll tap the left arrow to release the lock.

1:57 I’m purposefully skipping the down arrow for now.

2:01 We’ll come back to the down arrow key in a moment, let’s practice the basic axis directions first.

2:09 In our first example, start drawing an edge and tap an arrow key to invoke the lock.

2:15 I’ll lock the red direction with the right arrow key, and then to finish you’ll actually click your mouse on the point you are inferring to.

2:27 Practice a few times in just the red direction.

2:31 Start an edge, lock it by tapping the right arrow key, and finish by clicking a second time on your inference point.

2:38 Remember to hit esc to stop drawing a further edge.

2:43 Draw several edges until you are comfortable with basic locking, and then try locking in both the red and green directions as you draw...

2:54 In the next scene, we’ll give you some challenges to work on.

3:01 This puzzle uses only the Red and Green directions.

3:06 The objective is to follow the path provided, staying perfectly in the center, and we’ve provided these points for you to inference to.

3:17 Start here, lock the red direction, then infer and click on the first point.

3:25 Now lock the green direction with the left arrow key, and infer to the 2nd point.

3:31 Continue this process of locking the red and green directions, until you’ve completed the entire path.

3:42 The next puzzle is more complex, and also involves the blue direction.

3:53 Instead of having reference points, you should be able to infer to midpoints.

4:06 As you draw edges, you’ll also see that you don’t always need to lock a direction, such as this vertical edge, which I can simply draw to the next midpoint.

4:17 Take your time, figure out each next inference.

4:22 You’ll probably need to orbit or zoom in and out as you progress, but practice until you can complete the entire path.

4:51 Now, let’s return to the down arrow, and move to the next scene.

4:57 Tapping the down arrow will lock to an existing edge, so to use it, you need to start drawing a line first,

5:06 then hover over another edge and tap the down arrow key.

5:11 Both our line and the reference edge are highlighted magenta, and we are locked in a parallel direction.

5:18 Tap the down arrow key again to lock to a perpendicular direction and tap the key a 3rd time to release the lock.

5:28 Practice by finding the parallel and perpendicular lock to each of these bars.

5:34 Remember that you’ll need to release the previous lock, then hover over a new edge and tap the down arrow.

5:45 Once you feel comfortable finding and locking existing edges, try this:

5:52 I’m going to draw a line from this same corner, then hover over the same edge I’m drawing from and tap down to lock it.

6:01 Watch how the inference lock works as I reference points, vs other edges.

6:08 The reference to points is going to be a perpendicular reference, but if I hover over an edge the reference is where those two edges intersect.

6:19 Hover around on points and edges to see how they interact with our locked direction.

6:35 Keep in mind that this example is taking place in the same plane, all these edges are coplanar,

6:44 so we can find intersections between them.

6:47 If I moved this triangle surface upward, so it was in a different plane, there is no intersection between non-coplanar edges,

6:56 but don’t worry, in most cases you will actually be inferring to a surface.

7:02 For example, if I pull one of these bars up, we can then easily find an inference to that vertical surface.

7:14 Using the arrow keys for inferencing can be a really handy shortcut, but the more versatile method is to use the shift key.

7:24 Really, you should be comfortable using both.

7:29 To lock with the shift key, you need to find a direction first.

7:34 Let’s return to the first scene and erase out any edges you’ve drawn before.

7:40 So I’ll start drawing an edge in the red direction, then hold the Shift key down.

7:47 As long as I’m holding Shift down, I will stay locked, which is also indicated by the highlighted edge.

7:55 As before, to finish my edge, I’ll click on a another point in the model, and now that I’ve completed this edge, I can let go of the Shift key to release the lock.

8:07 To practice again, I’ll find the green direction.

8:12 Remember, find the direction first, then hold the Shift key down to lock it, reference, and click on other geometry to finish the edge, and let go of the shift key.

8:27 If you feel confident in using Shift for inference locking, try to complete the paths again, this time using only the Shift key to lock.

8:39 Remember, you can double click on your previously drawn edges to select them all, and then press Delete on your keyboard.

8:47 Work through both of these exercises again.

8:52 If you are still struggling with using the Shift key to lock, don’t worry, and just walk through the locking sequence several times:

9:02 Find a direction.

9:04 Hold Shift to lock that direction.

9:07 Complete your edge.

9:09 Release the Shift key.

9:13 For more practice, create a few simple boxes like we did with basic inferencing,

9:18 but now that you know how to lock edges, see if you can get faster in drawing with just the line tool.

9:28 We’ve focused on using the line tool to learn about inference locking, however you can also lock to surfaces and lock the move tool as well.

9:40 In the next lesson we’ll create a roof structure that will let us practice some of these additional techniques.