Creating Geometry in Sketchup
The most frequently used tools for creating geometry in SketchUp can be categorized into two groups: the Drawing tools and the Modification tools. To get started with any model, you must first create the geometry using the Drawing tools (the Line tool, Rectangle tool, Circle tool, Arc tool, Polygon tool, and Freehand tool).
Once you’ve created simple 2D geometry, you can shape and change that geometry into a more complex form using the Modification tools (the Move tool, Push/Pull tool, Rotate tool, Follow Me tool, Scale tool, and Offset tool). Throughout the modeling process, you will likely go back and forth between these toolsets (Figure 4.10). Use the Drawing tools to create simple 2D geometry and make additional edges to break surfaces to set up operations for the Modification tools.
Drawing Tools
The Drawing tools can be further broken down into two groups: the Surface Drawing tools and the Edge Drawing tools. A Surface Drawing tool creates a closed loop of coplanar edges, including a surface, in a specified shape. An Edge Drawing tool creates straight and curved edges (no surface). These tools provide infinite combinations to complete additive and subtractive modeling operations (Figure 4.11).
Surface Drawing Tools
The Surface Drawing tools include the Rectangle, Circle, and Polygon tools. All of these tools create a closed loop of coplanar edges and a surface. It is best to start building a model using these tools (Figure 4.12).
To use the Surface Drawing tools, you’ll need to click twice. Click once to start, move your cursor to suggest a direction, then click again to finish. Keep in mind that you can enter precise dimensions during the command or after the command, until another command is started. The same is true for most SketchUp tools.
TIP : The best way to execute most SketchUp commands is to use the click-and-release method. The click-and-drag method will get you into trouble because it is easy to accidentally perform small unnoticeable commands with many of the tools. Typically, you should click once to start, move your cursor, click again to finish, and then enter a precise dimension.
Rectangle Tool
The Rectangle tool is a very effective tool for creating surfaces, and it certainly is one of the most frequently used tools in SketchUp. One of its great features is that the geometry it creates is always aligned with the axes. This means that you can create four edges and a surface, all squared up, with just two clicks (Figure 4.13).
1. Activate the Rectangle tool and click once to start.
2. Move your cursor to suggest a direction and click again to finish.
3. At this point, you can enter precise dimensions such as 120,120, then press Enter.
TIP : you can override the alignment with axes by starting a rectangle on an off-axis edge. The rectangle tool will align new geometry with the edge on which it is started.
Circle and Polygon Tools
Because SketchUp is a surface modeler—meaning that the basic building blocks are edges and surfaces—there are no “true” circles in SketchUp. All circles are represented by a series of connected edges. The more sides a circle has, the smoother it looks (Figure 4.14). The default number of sides for a circle is 24 sides, and this number works for just about any circle you will need to create. Keep in mind that when you extrude a circle into a 3D form, every edge will become a surface with three additional edges. As a result, the more edges you have, the more 3D surfaces you create, and ultimately the slower your model will perform, which can be problematic.
Be aware of what you are modeling and how many sides you will need to achieve the quality you want. If you are creating a close-up rendering of a column, it would be appropri- ate to increase the number of sides before you create the circle base of the column. If you are rendering several columns for a building off in the distance, you could decrease the num- ber of sides used to create the circle bases of the columns. There are times when a drastically lower number of sides is not noticeable. When you activate the Circle tool, you can change the default number of sides used to represent a circle (Figure 4.15).
To create a circle, follow these steps:1. Activate the Circle tool, then immediately type 48 and press Enter to change the default number of sides on a circle to 48 sides.
2. Click once to define the center point of the circle.
3. Move your cursor away from the center point on axis, click again to finish.
4. At this point, you can enter a precise radius such as 120, then press Enter.
The Polygon tool works the same way the Circle tool does. The difference between the two is that a polygon’s edges are not softened when extruded (Figure 4.16).
Edge Drawing Tools
The Edge Drawing tools include the Line, Arc, and Freehand tools (Figure 4.17). These tools only create edges, not surfaces. You can use the Edge Drawing tools to make small additive and subtractive adjustments to existing surfaces. Although they aren’t the most efficient tools for creating surfaces from scratch, you can use them to actually draw the sides of a closed loop of coplanar edges.
Line Tool
The Line tool is the most basic Edge Drawing tool in SketchUp, and it is the tool with which most designers begin. Although it has many uses, surprisingly, using it is not the most effective way to create geometry. The Line tool is best used to make small adjustments and modifications.
When you’re drawing in 3D with the Line tool, you can draw on axis by locking the Line tool on an axis.
To lock an axis, first find the axis and then hold down the Shift key to lock it. Finish the operation by clicking on a point to define the distance, and then release the Shift key. You can also lock an axis by tapping an arrow key while drawing a line. The Right arrow key locks the red axis, the Left arrow key locks the green axis, and the Up and Down arrow keys lock the blue axis.
Locking an axis eliminates two of the three dimensions, so all you need to do is define a distance along the specified locked axis (Figure 4.18). You can do this by using the inference engine to snap to a point, edge, or surface. Also, you can enter precise dimensions into the Measurements dialog.
The Line tool can also be used to heal surfaces (Figure 4.19). Right-click on an edge of a surface and choose Erase. When you erase an edge, you break the closed loop of coplanar edges and, in turn, lose the surface. Redraw the line from point to point and you will have the edge and surface back.
Now, right-click on the surface and choose Erase to delete only the surface. Use the Line tool to retrace any edge around the closed loop of coplanar edges. The surface is now healed (Figure 4.20). Keep in mind that because geometry does not stack in SketchUp, there is only one edge remaining where you traced the edge.
Arc Tool
Use the Arc Tool to create precise curves. 1. Click once to define the starting point of the arc. 2. Click again to define the endpoint of the arc, or enter a precise dimension into the measurements dialog. 3. Click once more to define the bulge (Figure 4.21). Using the Measurements dialog, you can also enter a specific distance for the bulge.
When you’re using the Arc tool to round the corners of a rectangle, look for the magenta Equidistant and Tangent to Edge inferences (Figure 4.22). When you’re continuing an arc, look for the cyan Tangent at Vertex inference to make a smooth transition between the two arcs (Figure 4.23).
Freehand Tool
The Freehand tool is one of the few tools that require you to click and drag (Figure 4.24). You can use it to draw loose, sketchy lines.
1. Click and drag to draw a line. Release on the starting point to finish and create a surface.
TIP : To learn how to draw more accurate loose curves, read about the Bézier curve plugin in chapter 8, “ruby Scripts.”
Modification Tools
Once you’ve created the geometry using the Drawing tools, you can change it using the Modification tools (Figure 4.25). The Modification tools can quickly transform 2D geometry into 3D objects and quickly create complex geometry by scaling, stretching, moving, and copying.
The Select Tool
The Select tool is included in the Principal tools, but it is critical for using the Modification tools. Of all the tools you need to master, this one is by far the most underestimated and the most important. You will use the Select tool before you use most of the other SketchUp tools. Typically, you will default back to the Select tool after issuing a command. All modification operations are complemented by the Select tool. It is best to preselect an entity before you use the Modification tools. Some of the Modification tools have a hot spot that auto-selects entities, but you will find that you can obtain complete control by first preselecting an entity with the Select tool.
Click once on an edge or surface to select it. Double-click on a surface to select the sur- face as well as the bounding edges. Triple-click on a surface to select all of the connected geometry (Figure 4.26).
To perform a window selection, click and drag from left to right over the entities you want to select (Figure 4.27). Only the entities that are completely in the selection window will be selected. A window selection is represented by a solid selection window.
Hold down the Ctrl key (Option on Mac) while you are using the Select tool to add entities to the selection. Hold down the Ctrl (Option on Mac) and Shift keys while you are using the Select tool to remove entities from the selection. Hold the Shift key while you are using the Select tool to inverse the selection. All of these modifier keys work with selec- tion windows, too (Figure 4.28).
TIP : Before starting any command it is best to clear all selections. you can deselect all of the entities in a model by clicking on the edit drop-down menu and choosing Deselect All, or by right-clicking on the model background.
To see additional selection options, right-click on an edge or surface (Figure 4.29). From this menu, you can select Bounding Edges, Connected Faces, All Connected, All on Same Layer, or All with Same Material. These unique selection options can help you make complex selections faster.
If you find yourself tediously picking through a model, keep in mind that there is always a fast and easy way to make the selection you need. Use a combination of all of the selection techniques to select only what you need in the most effective manner. Approach the selec-tion process just as you do the modeling process; the process can be additive or subtractive. Before starting the selection, ask yourself if it would be easier to select several entities and then deselect what you don’t need, or would it be better to add each piece individually. Per- haps using a combination of the two techniques would be the most effective. Every selec- tion is different, so be sure to keep your approach flexible.
The Move Tool
The Move tool’s efficiency relies heavily on the stickiness of the geometry. You can move points, edges, and surfaces using the Move tool. Moving each of these entities has a different effect on the entity, as well as the adjacent, connected entities (Figure 4.30). The Move tool’s hot spot is right in the middle of the icon. Place your cursor on an edge or a surface, and note that the Move tool will auto-select entities. Click once to pick an entity up, then click again to put it down.
TIP : Beware! The Move tool is the number one destroyer of models. Be careful about what you are selecting and what is beyond your selection. you can select entities that are visibly blocked by other geometry, which makes it very easy to move entities accidentally and “blow out” the back of a model.
Precise Move
A precise move is executed by preselecting entities and then moving the selection from a specific spot on the selection to another specific spot in the model (Figure 4.31). A precise move can be started and ended on an edge, endpoint, midpoint, or surface, depending on the desired final location.
To make a precise move, follow these steps:
1. Using the Select tool, preselect the entity you want to move.
2. Activate the Move tool. Hover on the front-bottom corner of the cube until you see the Endpoint inference notification. Click once to pick up the cube.
3. Move your cursor, and the cube, to the front-bottom of the large cube. Hover on the corner until you see the Endpoint inference notification and click to place the cube.
TIP : Don’t “eyeball it” when you can be precise. When performing a precise move, be sure to snap to other entities in your model.
Linear Copy and Array
The Move tool is also the “copy tool.” To toggle the Copy command on and off, tap the Ctrl key (Option on Mac). As you are moving any entity, tap the Ctrl key (Option on Mac) to leave a copy of it behind.
To make a copy, follow these steps (Figure 4.32):
1. Using the Select tool, preselect the entity that you want to copy.
2. Activate the Move tool and click once on the entity (you could start the copy from anywhere in the model).
3. Tap the Ctrl key (Option on Mac) to toggle on the Copy command while you move the cursor along an axis, then click again to finish.
4. At this point, enter a precise distance into the Measurements dialog, such as 20f, then press Enter.
5. To create multiple copies at a specified distance, immediately after you complete the Move/Copy command, enter the number of copies you want to make—for example, type 4x, then press Enter. This will create four copies of the selection in addition to the original, just as a copy machine would (Figure 4.33).
Another way to array using the Move tool is to divide the distance between the copies (Figure 4.34). After you complete a copy, specify the number of divisions between the two copies within the Measurements dialog, as follows:
1. Using the Select tool, preselect the entity that you want to copy.
2. Activate the Move tool and click once on the entity (you could start the copy from anywhere in the model).
3. Tap the Ctrl key (Option on Mac) to toggle on the Copy command while you move the cursor along an axis, then click again to finish.
4. At this point, enter a precise distance into the Measurements dialog—for example, type 100', then press Enter.
5. Immediately after entering the distance, enter the desired number of divisions between the two copies—for instance, type 5/, then press Enter.
You can continue to modify the copy and array until you start another command. Try entering different numbers of copies and different distances, and switch between using mul- tiply and divide arrays. Once you click on another tool, you will lose the ability to modify the array (Figure 4.35). At that point, the new geometry will be just that, geometry. You will need to delete or reposition geometry to change the array.
Auto-fold
If a surface does not have the proper lines, or breaks, to fold the surface and allow the selection to move on all axes, it can stick to another surface. The Auto-fold command automatically draws all the lines needed to break a surface and allow the selected surface to move in any direction (Figure 4.36). While performing a move, tap the Alt key (command key on Mac) to toggle the Auto-fold command on.
TIP : Don’t use the Auto-fold command as a crutch. Sometimes it can appear to help make an entity move where you want it to, but it can actually create off-axis geometry that will be problematic later.
Push/Pull Tool
The Push/Pull tool is one of the fastest and easiest ways to generate large amounts of geometry. The Push/Pull tool extrudes 2D surfaces into 3D forms, perpendicular to the starting face. This means that geometry is typically on axis, or at least perfectly square with the starting surface. The Push/Pull tool affects only surfaces. Just follow these steps:
1. Position the Push/Pull tool on a surface; it will auto-select the surface. The hot spot of the Push/Pull tool is at the tip of the red arrow on the icon. Click on the surface to start the operation.
2. Move your cursor to push or pull the surface. The surface will extrude perpendicular to the starting surface (Figure 4.37). Click again to finish.
3. At this point, you can enter a precise dimension, type 5', then press Enter.
Tap the Ctrl key (Option on Mac) before or during any Push/Pull operation to leave a copy of the starting face (Figure 4.38). This is a toggle, so tap the Ctrl key (Option on Mac) again and the starting face will disappear. In Chapter 17, “Site Analysis: Documenting an Existing Building,” you will see how valuable this function is for creating floorplans.
TIP : The Push/Pull tool has a memory. once you have completed a Push/Pull operation, you can double-click on another surface to reproduce the last push/pull.
Follow Me Tool
The Follow Me tool generates massive amounts of complex geometry with very few clicks. This tool works by extruding a 2D profile along a path (Figure 4.39). A path can be a series of connected edges, or a surface which defines the path with its bounding edges. Follow these steps:
1. Using the Select tool, preselect the path, in this example a surface.
2. Activate the Follow Me tool.
3. Click on the profile to finish.
TIP : The profile does not have to touch the path for the follow Me tool to work, although the operation and results make more sense and are easier to predict if it does touch the path.
Rotate Tool
2. Activate the Rotate tool. Click and hold at the desired center point of rotation, and drag away to set the axis of rotation. Look for the inference line to turn red, green, or blue. Release once you have found the desired axis of rotation—for this example, rotate about the red axis.
TIP : Use guides or encourage an inference to specify a meaningful center point of rotation.
3. Move your cursor around and notice that it is locked at the defined center point of rotation. Click to define the reference angle. The reference angle can be arbitrary for most rotations, unless you are trying to align one object with another.
4. Move your cursor and click again to define the degree of rotation away from the ref- erence angle. You can click at a random angle, or
5. At this point let go of the mouse and enter a precise angle into the Measurements dialog—for example, type 90, then press Enter. This will rotate the object 90 degrees off the reference angle around the defined center point of rotation.
Similar to the Move tool, during any rotation, tap the Ctrl key (Option on Mac) to toggle on the Copy command. This will leave a copy of the selected object behind (Figure 40.41). To perform a polar copy and array, follow these steps:
1. Pre-select the entity you wish to rotate and copy. Activate the Rotate Tool, hover on a point to encourage an inference and use a meaningful starting point.
2. Click and drag and release on the blue axis.
3. Move your cursor to the right and click once to set the reference line. Tap the Ctrl key (Option on Mac) to toggle on the Copy command while you move your cursor down the screen.
4. Click to place the copy.
5. Immediately type a precise degree of rotation, such as 90, then press Enter.
6. To make three copies, immediately type the number of copies as 3x, then press Enter. You can continue to change both the degree of rotation and the number of copies until you invoke another command.
TIP : Similarly to the way you use the Move tool, you can also enter the overall copy rotation and specify divisions. for example, after making a copy type 180, then press enter, immediately type 5/, then press enter. This will make the original copy at 180 degrees and fill the space between with five divisions.
Scale Tool
The Scale tool distorts entities based on a scale factor or a “hard” dimension. The hot spot of the Scale tool is at the tip of the red arrow, but it usually is best to preselect entities before scaling. Follow these steps:
1. Using the Select tool, preselect the entity you want to scale.
2. Activate the Scale tool and click on the top center grip.
3. Move your cursor to scale the object and click to finish the command.
4. Immediately enter a scale value, such as 1.5, then press Enter.
2. Move your cursor to suggest the direction of the offset and let go of the mouse.
3. At this point, you can type a precise dimension, such as 2', then press Enter.
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