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Drawing a model in 3D is different from drawing an image in 2D. This introduction to drawing basics and concepts explains a few ways you can create edges and faces (the basic entities of any SketchUp model). You also discover how the SketchUp inference engine helps you place those lines and faces on your desired axis.
Table of Contents |
Use the Line tool to draw edges (also called line entities). Edges form the structural foundation of all models. Here’s how to draw a line:
You can edit the length of a line as long as it doesn’t bound a face. Here’s how to edit a line:
When you join several lines into a shape, they form a face.
Not a funny face, or a scary clown face, or even a cute puppy face. By default, faces are plain, but super important: They’re the other half of the duo, edges and faces, which enable every SketchUp model ever made to exist.
When you draw a line (or a curve) on an existing face, you split the face.
You can erase an edge or face to create an opening in a shape. To see how erasing an edge affects your model, first select the Eraser tool () in the toolbar or press the E key, and then click an edge:
In the figure, you see the original cube and how erasing an edge or face changes the cube.
If you accidentally delete a face, here’s how to bring it back:
SketchUp has an inference engine that helps you work in 3D space. For example, when the Line tool cursor is hovering over the midpoint of another line, the inference engine tells you by displaying a light blue dot and ScreenTip that says, “Midpoint,” as shown here. Every inference has its own color and ScreenTip. (See Knowing your inference types for a full list.)
The inference engine can also help you find geometric relationships between lines. For example, it tells you when a line you’re drawing is perpendicular to another line. In the following figure, notice that a colored dot also appears at the start point of the line, giving you a few bits of information all at once.
SketchUp displays several types of inferences: point, linear, and shape. SketchUp often combines inferences together to form a complex inference. Also, components and dynamic components have their own inference types.
A point inference is based on the exact point of your cursor in your model. The following table lists the point inference types.
Point Inference Type | What It Looks Like | What It Means |
---|---|---|
Endpoint | End of a line or arcEnd of a line, arc, or arc segment | |
Midpoint | Middle point on a line or edgeMiddle point on a line, edge, or arc segment | |
Arc Midpoint | Middle point on an arc | |
Intersection | Point where a line intersects another line or face | |
Intersection with Hidden Section | Point where an edge that is generated by a hidden section plane intersects with the drawing tool | |
On Face | A point that lies on a face | |
On Edge | A point that lies on an edge | |
Center | Center of a circle or arcCenter of a circle, arc, or polygon | |
Guide Point | A guide point | |
On Line | A point along a guide line |
A linear inference snaps along a line or direction in space. In addition to a ScreenTip, a linear inference sometimes displays a temporary dotted line while you draw.
Linear Inference Type | What It Looks Like | What It Means |
---|---|---|
On Red Axis | Linear alignment to the red drawing axis (Click and drag as you draw to see the inference.) | |
On Green Axis | Linear alignment to green drawing axis (Click and drag as you draw.) | |
On Blue Axis | Linear alignment to the blue drawing axis (Click and drag as you draw.) | |
From Point | Linear alignment from a point; the dotted line’s color corresponds to the axis direction | |
Through Point | Draw from one point, hover over another point then hold Shift to lock the direction from the start of the drawing through the second point. | |
Parallel | Parallel alignment to an edge | |
Extend Edge | Continuation of an existing edge | |
Perpendicular | Perpendicular alignment to an edge | |
Tangent at Vertex | Arc whose vertex is tangent to a previously drawn arc's vertex |
Shape inferences help you pinpoint the moment when a rectangle becomes a square, for example. The following table lists all the shape inferences.
Shape Inference Type | What It Looks Like | What It Means |
---|---|---|
Square | A rectangle whose sides are all the same size | |
Golden Section | A rectangle whose properties match the Golden Ratio as found in mathematics and the arts | |
Half Circle, Quarter Circle, or Three-Quarter Circle | An arc that is exactly one half of a circle, one quarter circle, or three-quarters of a circle, respectively. | |
Arc Side and Center | An arc shows edge and center inferences when a drawing tool hovers on the arc. | |
Circle/Polygon Center | A circle shows and center inferences when a drawing tool hovers on the circle edge. |
And you can see how inferencing has changed in SketchUp 2016
By locking inferences, you can confidently draw along the direction you intend to draw. Another reason to lock an inference is to maintain one drawing direction while you reference geometry from another part of the model. That’s a more advanced move, but very helpful. The easiest way to lock an inference to the default axes directions is to use the arrow keys:
Key | What it looks like |
---|---|
↑ | Locks the drawing direction or drawing plane to the Blue axis |
← | Locks the drawing direction or drawing plane to the Green axis |
→ | Locks the drawing direction or drawing plane to the Red axis. A good way to remember left from right is to say “Right locks Red.” |
↓ | Locks the drawing direction to the Blue axis Toggle to lock the parallel/perpendicular drawing direction or drawing plane to an inferenced edge or plane. Basically, anything that turns magenta. The drawing direction will turn magenta in color as well as the edge of face that is being inference. |
Shift | Locks the drawing direction or drawing plane to the active drawing direction/plane. So if you’re drawing along the Blue axes and hold down Shift, the Blue inference will lock. |
Some tools, like the circle and rotate tools, can lock to a plane (instead of a drawing direction) as shown below. For these tools you can lock the drawing plane by choosing the colored direction for the tool’s axis or “normal”.
To ensure your edges align to axes, you may find it helpful to change the cursor to the axes colors. Or if you need to check the alignment of existing geometry, change your edges to the axes colors.
To change your cursor to axes colors, follow these steps:
To make the edges in your model reflect the axis color to which it is aligned, follow these steps:
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