4 Tips for Moving in 3D in SketchUp

Matt Donley Sketchup Tutorials, Tips & Tricks 22 Comments

Imagine a 3D printer for a moment. The extruder can move along three axes; (X,Y, and Z). Now, imagine that you are a programmer, and you need to write code that will allow you to control the position of the extruder in 3D space, using only the X & Y position of a mouse cursor (No buttons or scroll wheel, just the position of the mouse).

When you move the mouse up, should the extruder go higher on the Z axis, or should the Y axis move deeper? Maybe a combination of the two? How do you determine that? How do you convey a 3D position using only a 2D input device?

This seemingly impossible scenario is a common challenge that any 3D modeling software must face, and I think SketchUp does surprisingly well in this regard.

In this tutorial, I will help you better understand how SketchUp tries to “read your mind” in determining which direction you intend to move objects when you are trying to move them along three axes simultaneously. I will also share 4 tips on how to force SketchUp to move objects exactly where you want them to go.

Watch the video or continue below

Common Problems

There are many times when you need to move an object to a position that has a different X Y and Z coordinate than its current position. When this occurs, the first thing most people will try to do is move it directly into position, only to find that SketchUp will not move the object into place, no matter how hard you try.

3D Movement Priority

Now there is a lot of calculating that SketchUp is doing “behind the scenes”, so to completely reverse engineer SketchUp’s inference system is sort of beyond what I’m trying to do here. And that’s not really the point of this tutorial anyways. The inference system is supposed to feel very intuitive, natural, predictable, and obvious. And I think it does a pretty darn good job at that. However, I think it is helpful to at least dive in just a little bit to try and understand exactly what SketchUp is doing.

Like I said, there are several factors that determine the “strength” of SketchUps various inferences, whether it’s a point lock, edge lock, face lock, or plane lock, so there are several combinations of things you can do to increase the likelihood of SketchUp moving an object the way you intend it to move.

Camera Position

The position of the camera plays a strong role in suggesting to SketchUp how to move the object. You might consider it to be an “invisible” third input in addition to the X and Y movement of the mouse. When you move an object across empty space, SketchUp will primarily move an object along a single plane (unless you are snapping to some other geometry in your model). The point from which you start the move will always intersect the plane, but the orientation of the plane will strongly depend on the orientation of your camera. The plane will always align with either the X|Y, X|Z, or Z|Y plane.

When you orbit the camera to a top view (looking down on your model), SketchUp will strongly favor locking to a plane perpendicular to the Z axis. If you align to a front view, the movement will lock to a plane perpendicular to the green axis. The same thing happens with the red axis.

Most times, you’re not modeling while the camera is perfectly aligned to an axis, so how does SketchUp choose which plane to lock to when you’re viewing the model at an angle?

Mouse Position

There is a certain relationship between the mouse position, and how the axes origin is positioned between the camera view and the horizon in the distance. But this gets a little too nitty gritty, and really isn’t something that needs to be explored. Just know that if you move your mouse to a different position on the screen, SketchUp may jump to a different plane orientation which more closely represents the direction you’re trying to move.

So it’s a combination of the camera position and mouse position that determines which plane SketchUp will lock to, when moving an object across empty space.

Snapping to Geometry

When you move an object along “empty space”, it will always align to a plane (as described above). But as you hover over other geometry in your model, you begin to enter a minefield of inference points and faces to snap to. Snapping to Geometry will always override the default movement plane.

You can snap to end points, edges, faces, axes, temporary tracking from points (among other things) in your model. Learn more about the SketchUp Inference system here. The tricky part, is that the entities that you are moving can actually get in the way of what you are trying to snap to. This results in SketchUp “not seeing” the snap point (because they are hidden behind the faces of the object you are moving), and reverting back to the default plane of movement.

4 tips for Geometry Interference

It can be frustrating when SketchUp isn’t snapping to what you want it to. Here are several tips for solving these issues.

1 – Keep the destination closer to the camera – I’ve been trying really hard to figure out the best way to describe this tip. Basically, if the point you are trying to move to is further away from the camera than the starting point, you are less likely to snap to it. Instead, orbit the camera so that the destination point is closer to the camera than the starting point. SketchUp prioritizes things that are “in front of” other things.

2. Turn on XRay mode – With XRay mode on, (View > Face Style > X-Ray) you can see through faces, and the SketchUp inference engine will always prioritize edges and points. This is great for simple models, but when you have a ton of geometry in your model, there are too many points to snap to, and it can be hard to identify which point you actually want.

3. Temporary Axis lock – If you’re having trouble snapping to a point because the entities you are moving are getting in the way, you can temporarily get them out of your way by locking their movement to a random axis. After you’ve started a move, tap an arrow key to lock an axis, and this will allow you to hover your mouse over any point in your model while keeping the entities you are moving out of your way. Once you’ve locked onto the point, tap the arrow key again to release the axis lock, and your geometry will immediately snap to that point. Be sure not to move the mouse (or else you’ll lose the snap), and click to finish the move.

4. Use a temporary guide surface – Most times, when I start a model, I’ll create a large rectangle on the ground and make it a group. This surface acts as an inference guide, since SketchUp will almost always prioritize snapping to a face over snapping to a default movement plane.

Axis Lock

The absolute most reliable, safe, and accurate way to ensure a movement in 3D space, is to not move in 3D space (all at once). Instead, move the object along one axis at a time. When moving an object, tap one of the arrow keys to lock the movement along a single axis. Repeat this for the other two axes.

The disadvantage is that it’s slower, but you’ll have precise control over the distance along each axis because you can type in a distance for each axis individually, or choose to snap to another point in your model for some.

Comments 22

  1. Thanks for the post. I’ve noticed 3D text doesn’t necessarily move in all axis’ after it has been placed in the drawing. Have you experienced this? Do you have a work around that you use?

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      Hmmm, that’s strange. I’m not sure why 3D text would act any differently than any other entity. I wonder, If you Right-Click on the group, do you see anything that says “Unglue”? There is a feature in SketchUp that lets you “glue” an object to a plane, but if you try to move it again, it remains stuck to that plane, so you have to unglue it.

  2. Matt,

    Thank you for the tutorial on 4 tips for 3D movement in Sketch-up. This issue drives me crazy all the time. Now I have 4 ways to stay sane.

    I’m 75 years old and use sketch-up to visualize woodworking projects and turned art pieces. When I do not have a active project I stay fluent in Sketch-up by draw small items I find around the house. One such item is a Tropicana Orange lid. It has some arch structures around the periphery I can not seem to get right. Do you have a tip on how to draw a cut boss on a curved surface?

    Thank you,

    Jerry

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  3. Thanks Matt. Another quick way to instantly move a uncooperative object is to hold the crtl button and move a copy directly to the point you’d like. Perhaps you knew this already.

    Always enjoy your insights. Also a happy owner of your Nick Sonder collaboration. Nice work!

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  4. Thanks for the good tips. Another method that is sometimes handy is to select the object, activate the move tool, click at a point in empty space, move the cursor and thereby move the object close to the desired position, then click to release the cursor from the object, then click on the point of the object and snap it to the destination point. This can sometimes reduce undesirable effects of the inference tool and allow more freedom of movement. Also, moving the cursor along one of the axes is equivalent to using an arrow key to lock the direction. You could also create a reference box and move the cursor along one of its edges if its not convenient to move the cursor along an axis. You could also create a line in a specific direction and move the cursor along it to move the object in that desired direction.

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      Lots of good tips here, thanks for adding those. I see what you mean. Moving while your mouse is over empty space prevents SketchUp from snapping, and naturally, you’ll lock to an axis. Get the object closer to the objective, and then you can do the final movement after.

  5. Hi Mat, I’m from Spain, first of all thankyou so much for your videos and notes. I wanted to know if you have some video or tutorial where I can learn or better master control of groups or components. As for instance: I have a photovoltaic panel that I have to place on a roof with different tilts, different angles, and I have to place the panel with the best angle, so I find that the panel has to be with a 20º tilt respect ground and the roof has two different tilts. I manage to place it, but I have to move around a lot. Do you a tip? Thank you so much.

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      Hmmm, well, I can say that you should explore the down arrow inference, which locks an inference parallel or perpendicular to whatever you are hovering over. So as you rotate the panel, you can hover over an edge of the roof, and tap down arrow, and the rotation will be parallel to the roof.

  6. One thing I recently discovered to move an object, is to use the Ctrl button.
    The Ctrl button is used to copy the entity, but if pressed twices it frees you from the limiting invisible guide plane.

  7. Hi Matt thanks for your tutes- good to get new tips and tricks.
    My favourite way trick to move in 3D is to use the shift key- super fast way to align to axes.
    Click the object, start moving along the axis/ construction line etc that you want to move along, then press and hold shift to lock movement along the axis. Then click on the point that you want to align to and youre done. Easy way to move an object along 1, 2 or 3 axes to get it all where you want it to be.
    Cheers
    Hamish

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  8. Hi Matt,
    I’m a big fan and have been studying your books. Thanks for the tips on moving pieces and parts in model space. It helps knowing your strategy.
    Another way I’ve overcome the difficulty moving things in 3D space (and to snap dimensions) is to draw a temporary line from the base point on the moving part to the target point of another part. Then use the line as a “guide rail”. As the base point moves along, the temporary line turns purple when its used as a guide. The advantage of adding the line is being able to put it on a layer that can be turned off. If the moved part needs to go back to the original place it eliminates guess work or unnecessary undo’s.

  9. Good tips Matt,

    Another that I find an absolute must have is to set your cursor to display crosshairs. Once set your cursor origin will have its own set of attached axii displayed in the standard colours which is really useful when working with complex models – never get lost again!
    Go to menu: window / preferences / drawing and check “display crosshairs” and while you are there do yourself a favour and check “disable pre-pick on push / pull tool” – you’ll thank me for it long term!

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      I personally don’t like the crosshairs, but the disable pre-pick on Push/Pull is an interesting setting I didn’t know about. I’ve gotten into the habit of double tapping the letter P, which does the same thing. A part of me feels like I don’t want to disable pre-pick, in case I want to extrude a face relative to some other distance reference in the model, but I honestly can’t think of a single time I’ve ever done that, lol. So maybe I will switch over.

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