Tuesday, February 9, 2010

7.1 Push/Pull Tool

Discuss this video at my Forum.

The Push/Pull tool takes a 2 dimensional surface and extrudes it into the third dimension. The most common example is to create a rectangular solid or a cube out of a rectangle or a square. In this tutorial, we will start with a rectangle, create a rectangular solid using Push/Pull, and then explore the various options available with Push/Pull, such as creating voids, creating a starting face, pushing and pulling a curved face, and pushing and pulling precisely.

So start up Google Sketchup 7. SketchUp requires a startup template so that it can do precise measurements or to create models for specific tasks. Click the Choose Template button. You can measure in feet and inches, or in meters or millimieters. SketchUp has special templates designed for specific tasks, such as architectural models, creating models for Google Earth, Product Design and Woodworking, and Learning SketchUp. For our purposes, we'll select Simple Template - Feet and Inches.

Click the Start Using SketchUp button. You now see a little person, standing up, seemingly against a blue line. The blue line represents the Up direction. There are two other lines, colored red and green. The red line is the X direction, as if the guy is walking forward. The green line is the y direction, as if the guy is walking into the sunset or background. Remember these colors because they're important in Google SketchUp. Graphically, red is X, green is Y, and blue is Z.

SketchUp has a handy "Instructor" window, where you can learn about all the features of the highlighted tool. You can show or hide the Instructor window by checking the Instructor item on or off from the Window menu. This tutorial is based on the Push/Pull features shown in the Instructor window. It's basically a video version of Instructor. Right now, the Instructor is telling us that the Select tool, the arrow, is highlighted. You can also see this from the toolbar, which shows the arrow, the select icon, as depressed, i.e., the active tool.

The first thing we're going to do is delete the person from the scene. We're not interested in him. The important thing is the Push/Pull tool. To do that, click on the person.
Note the solid blue lines around the person. These show what is selected. To delete the person, press the Delete key.

Now we're going to create a rectangle. To do that, click the shaded Rectangle icon in the toolbar. The Instructor gives us the options for the Rectangle tool. To draw the rectangle, do the following:

1. Click to set first corner.
2. Move the cursor diagonally.
3. Click to set second corner.

Pressing Esc at any time cancels the operation, indeed most operations in SketchUp.

It's time to give the rectangle some volume. Click the Push/Pull tool, the one with a red arrow pointing up. The Instructor shows you that the Push/Pull tool is active. It's telling you to click on a face. In SketchUp, a surface consists of faces and edges. An edge is the boundary line or lines, the face is what's contained inside the lines. A rectangle has 1 face and 4 edges. When the tool icon is not over the rectangle, the face color is a smooth grey. However, when the tool is over the rectangle, the face color changes to grey with dots inside. Move the tool over the rectangle. When the rectangle's face changes color, left click to select. This locks the tool, so to speak, onto the face. Move the tool up. Now the rectangle has volume.

The amount of height is shown in the Distance area. As we move the tool up and down, the distance changes. Let's suppose we want the height to be exactly 10 inchees. To do that, just enter 10" in the Distance area. The rectangle's height is now 10 inches. Press Enter to confirm.

A nice feature is that SketchUp remembers the last distance that was used. This is handy because if you double click on the same face, the height is repeated. The total height of the rectangular solid is now 20 inches. Press Enter to confirm.

This remembering is also useful if you want to create another face as you push or pull. To do that, select a face. Press the Ctrl key. Now there's a little plus icon in addition to the push/pull icon. Pull the face outward. An additional face has been created. This is very useful in creating diagrams, for example, for offices where you need to lay out rooms.

You can also hollow out this rectangle, subtracting volume from it, with a process called creating voids. To do that, we'll create a rectangle inside one of the faces of our rectangular solid. To do that, select the Rectangle tool and create a rectangle, as we did earlier in the tutorial, on the front face. Press the space bar to select the Select Tool. If you don't do that, you may end up creating more rectangles than you want.

Select the Push/Pull tool and move it to the new rectangle you created. Drag the rectangle inside the cube. You are in effect hollowing out the solid, creating a sort of tunnel area. Press the Space bar to make the select tool active. Now click the Orbit icon and orbit to the front. We created a "void", a tunnel inside the solid.

Of course, you didn't have to push completely through the solid. You could have stopped and created a partial tunnel. You also could have specified an exact distance to push or pull. To do that, use negative numbers. -1", for example, would push 1" into the solid, just as if you were creating a tunnel into it.

You can extrude a curved surface as well. To do that, press the Space bar to exit from the Push/Pull tool. Select the Arc tool. On a face, do the following:

1. Click at starting point of arc.
2. Move cursor.
3. Click at ending point of arc.
4. Move cursor perpendicular to line.
5. Click to finish arc.

Press the Space bar to exit the Arc tool. Click the Line tool icon, the Pencil. Connect the end points of the arc with a line. Now you have a curved face. Press the Space bar. Click on the Push/Pull icon. You can extrude this new face inward or outward. If you click Hidden Geometry from the View menu, you will discover that the curve is actuallly a series of faces lined up, not an actual curve.

I hope you enjoyed this exploration of the Push/Pull tool in Google SketchUp 7. If you did, don't forget to hit the YouTube Subscribe button. You can also discuss this tutorial at my forum.

No comments:

Post a Comment