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Inference Locking Practice

SU Fundamentals 12-2 Inference Locking Practice

0:02 For this lesson, open the practice file on roofs.

0:06 We are going to take this provided base and build this roof on it.

0:12 Now remember, there are always multiple ways of creating anything in SketchUp,

0:18 so the methods we are going to use here may not always be the best approach but they will give us an opportunity to practice inference locking.

0:29 To work with this file, we are going to introduce another tool that we haven’t covered yet, the Protractor tool.

0:37 The protractor is like the tape measure tool but for angles.

0:42 It will allow us to create guidelines at any angle we need.

0:47 Let’s start here, on this corner.

0:50 When I select the protractor, the first click will do two things:

0:55 It will both anchor the protractor and establish the plane we want to create a guideline in.

1:02 As you can see, the tool orients itself to any surface we hover over.

1:07 In this case, we need the green direction.

1:10 Inference locking will actually help us.

1:14 The arrow keys will lock the protractor to any axis, so pressing the right key would lock to red, and for us, let’s press the left arrow key to lock the green axis.

1:26 Now click once, on this corner.

1:30 Now that we’ve anchored the protractor, the 2nd click will define the base edge of our angle, so for us it will be anywhere on this edge.

1:41 Click once somewhere on the edge, then move your cursor up to establish the angle.

1:46 We could either type in an angle, or if we hover close the protractor gizmo, it will snap to every 15 degrees.

1:55 We need an angle of 30 degrees, so snap to the 30 degree tick mark, or type 30 and press enter.

2:08 Let’s do this again on the opposite corner.

2:11 I’ll use the protractor tool, press the left arrow key to lock it along the green axis, and click once on the far corner.

2:21 Now I’ll click a 2nd time somewhere on this base edge and then move my cursor up and click on the 30 degree tick mark, or type 30 and press enter.

2:34 We should now have two guidelines that we can trace over with the line tool to create a triangle surface,

2:42 then use push/pull to push this surface back, inferring to the far edge to finish.

2:50 Use the eraser to delete our guides, and let’s repeat these steps again on this area of the house.

2:58 Use the protractor, locked to the green axis to create two guides at 30 degrees.

3:11 Then draw in the roof shape and push/pull that shape back to here, where it meets this overhang edge.

3:28 Delete your guides and orbit around once again, where we will repeat these steps on this side of the house.

3:35 This time, we are locking the protractor along the red axis but still creating guides at 30 degrees,

3:53 then creating a surface and pushing this surface back, inferring to the opposite corner.

4:10 Take your time and get to this point in the model, with these 3 roof forms.

4:17 It’s crucial this is done accurately to continue.

4:23 Now let’s start to combine these separate roofs, starting with this smaller one.

4:29 Make sure nothing is selected, and choose the move tool.

4:33 Remember that move will auto-select objects if nothing is selected, including end-points.

4:39 Hover over this top corner end-point, click once to start moving it and because of the geometry it will only move in the green direction.

4:50 Don’t confuse this with being locked in the green direction.

4:55 If I hover over other points in the model, it’s not snapping to those points, unless we lock it.

5:01 Let’s press the left arrow to lock the green direction and now you can see it does snap to other points in the model, including this roof surface.

5:12 With our movement locked, we can click anywhere on this adjacent roof surface to move our endpoint exactly to that surface.

5:23 Let’s do this again, on the larger roof.

5:26 Make sure nothing is selected, then click once with the move tool on this endpoint.

5:32 This time it should be restricted to the red axis, but again, it’s not locked unless we hold the shift key or press the right arrow key.

5:41 After locking the red direction, hover over and click on our previous roof surface to line it up exactly.

5:49 If this is done correctly, we should be able to erase the dividing edge between these roofs.

6:03 With that done, we can use a similar approach on these two larger roofs.

6:09 Start moving this endpoint, lock the red direction and find the best surface to lock to and click on,

6:17 which is actually the near roof, as it will extend and merge these surfaces and edges.

6:24 This means we also broke this edge underneath here,

6:28 so can move the same point again, lock the red direction again, and this time click on the other roof surface to line it up.

6:37 Erase the dividing edge to finish.

6:42 Ok, right now we’ve got these three ends, or extensions on our house, and this is referred to as a gable end.

6:52 We are going to make these hip ends by tilting the roof back, but we want to keep our 30 degree angle.

7:01 We’ll complete each end in a different way just to show some of the options you might try.

7:10 On this side, we’ll make things easy by using some of our existing geometry that we know is already correct.

7:19 Simply select this edge, then using the Move tool make a copy of it from this corner, to the end corner.

7:30 Now we have an easy reference point to move our ridge point back to.

7:35 You don’t have to use locking, but feel free to do so if you’d like for practice.

7:43 Now for this end, we could use an existing edge, but what if we didn’t have an existing edge to work with.

7:51 Get the protractor, lock it in the red direction and let’s create another 30-degree guideline as a reference.

8:00 We will need more than just this guideline though.

8:04 You can see if we try moving the ridge\ point and locking it, that the guideline alone is not enough, we need a surface to lock to.

8:15 Use the line tool, start from this corner and trace over our guideline, something like this.

8:23 The exact distance won’t matter.

8:27 Now draw a line in the red direction, lock it and infer to our existing roof surface to finish,

8:33 then draw a final edge to complete this reference surface.

8:39 With our reference complete, move the ridge point, lock it and infer to the surface we just created.

8:49 Now erase that reference geometry we no longer need.

8:57 For our 3rd example, let’s combine the two concepts we just learned.

9:03 We’ll use existing geometry, as a reference surface to lock to.

9:08 Either of these two surfaces are at the correct angle we need, so I’ll select one,

9:15 then use the Move tool and make a copy of this surface from this end-point, down to the corner that is the base of the angle I need.

9:26 Now, I can deselect everything, move the ridge corner, lock the green direction, and infer to my copied surface.

9:38 Now, everything we’ve done to this point, could have been done in multiple ways.

9:44 More ways than we have time to show and it’s perfectly ok if you’ve had to redo and re-watch parts of this video to get this far.

9:53 Inference locking takes a lot of practice and exploration to master.

10:01 In this final dormer example, I’m going to introduce some advanced techniques, that rely more heavily on the Shift key for locking than we’ve done previously.

10:13 Make sure you are already comfortable using the shift key for basic locking.

10:21 We are going to start with the line tool and we are going to lock to this large roof surface before starting an edge.

10:31 I’ll hover on the surface and I get the blue On-face inference.

10:36 Hold the Shift key down to lock to this surface.

10:41 Being locked to the surface means I can only find inferences or only draw on the plane of that surface.

10:48 So, I’m still holding the shift key down to maintain the lock, and I’m going to hover over this vertical edge,

10:54 which jumps my inference to where that edge would meet the surface.

11:00 I’ll click once on the vertical edge to start my line on the roof surface and I'm still holding Shift down, so I’m still locked to the roof,

11:11 which means if I move my cursor now to this other vertical edge and click on it, I’ve created an edge on the roof surface, exactly above this wall.

11:22 Now, I can let go of the shift key to release the lock.

11:29 With the base edge completed, I’ll draw an edge 24 inches high in the blue direction,

11:37 Then draw back, lock in the red direction and complete a rectangular surface.

11:43 With this rectangle, use the protractor to create guides at 30 degrees and draw in the surface.

11:55 We can erase the guides and dividing edge, and if you’d like to flip the surface, right-click on it and choose ‘Reverse Face’.

12:11 Now we'll draw the ridge line by starting an edge, locking the green direction and inferring to the roof to finish.

12:20 Hit esc to stop drawing, then start another edge from the lower corner, find and lock the green direction, and infer to the roof to finish,

12:31 Then draw in the two remaining edges to complete this side of the dormer.

12:38 On the opposite side, we’ll practice a different method.

12:44 This time start drawing an edge from the back corner of the ridge and remember, click once to start that edge, don’t hold your mouse button down.

12:54 With our edge started, we’ll hover over this front corner, only hover, to find an inference to it.

13:02 Now, move the cursor away and find the green inference to that point,

13:06 and with the green inference showing, hold the Shift key to lock that inference.

13:12 With that inference lock, we can return to our surface, where our line snaps exactly where it should be.

13:19 Click to finish our edge, then let go of the Shift key to release the lock, and finish this surface with another edge.

13:30 Fill in this last surface and let’s extend this dormer based on the walls below.

13:38 This time, instead of drawing the base edge, we can simply copy it.

13:43 Select the bottom edge, copy it from somewhere on the edge, say the mid--point and lock the blue direction to infer to and click on the roof.

13:58 I’ll draw another edge in the blue axis, 24 inches high.

14:03 Then zoom in on this area of the dormer to create a few more edges that we’ll need.

14:10 We need a simple vertical edge to the first corner,

14:15 and then we could either hover over the front edge, or just use the down arrow key to lock a parallel direction for drawing this edge.

14:26 With that complete, zoom back out and orbit so we can see the far side of our dormer, which we are going to infer to.

14:37 Now, start an edge from our vertical line, hover over one of these edges and press the down arrow key to get a parallel lock.

14:48 Infer to and click on that back edge and then complete this surface.

14:57 You can complete the rest of this dormer with techniques we’ve already covered.

15:03 At this point you’ve been introduced to multiple ways to use inference locking, and there are still more.

15:11 Challenge yourself to go back and recreate this roof using different methods.

15:16 Using only the Shift key, or try using only the line tool.

15:23 True masters of SketchUp have mastered inference locking.