SketchUp is a powerful way to visualize your ideas. Better yet, you can download the program free of charge from Google. Going from a scanned concept to a three dimensional model is not self-evident, and there are some tricks that will make the process go much more smoothly.  This article will step you through the steps needed to take a scaled hand-drawn sketch and import it into a SketchUp model.

For this exercise, you should already have experimented with SketchUp. You know what most, if not all, of the tools do. You know that typing a dimension while using the push/pull tool will cause it to extrude an object by that distance. You also know how to set exact guides with the tape measure. The multiply and divide commands are old friends, too. You know what the color coding of the X, Y and Z axes mean, too.

You’ll need a good design as a base for your model. Developing an idea is still something that works better on tracing paper over a scaled base plan. Work out the landscape’s functions, place your elements, sketch in the major details. While you’re doing this, keep thinking about what your design is doing in three dimensions. This can be done on cheap tracing paper, since it’s going to be discarded once it’s been scanned.

When you’re happy with your basic design and have a reasonably clean plan drawn out, add a north arrow and a bar scale that clearly shows lengths in your design. Write the numbers large, since when they arrive in SketchUp they’ll probably be fuzzy and hard to read if they’re too small. These items are essential for scaling your model and for determining the correct shadows.

If your plan is large, it will probably be easier to photograph it digitally with a macro or telephoto lens. Don’t use a wide angle lens, since this type of lens tends to cause straight lines to bend. You can still correct this in Photoshop, but this requires an extra step. Try to shoot perpendicular to the plan from a distance as this also minimizes distortion. Another option is scanning the plan in pieces an re-assembling it in Photoshop, a tedious process but sometimes the only choice.

You can also enter your design into a CAD program, output it as a PDF file and import it into SketchUp. Since SketchUp is typically used to present concepts, taking simple rough sketches directly into SketchUp is less time consuming at this point in the design process.  Again, make sure it has a bar scale and north arrow, since it won’t arrive in SketchUp already scaled.  I’ve had mixed results importing CAD files into SketchUp, so I prefer using the traced pdf method. Tracing out a plan is a relatively simple and quick process, so less time will be lost compared with fixing an imported CAD file.

Once your concept is digitized and sitting on your hard drive, save a copy. SketchUp can read jpg, and pdf formats, so I tend to use these for scanned plans and files from CAD systems, respectively. It also reads Photoshop files.

Launch SketchUp. It will automatically create a new file for you. It might put up a tutorial or info screen. Close the screen unless you want to put your project aside for a bit and explore the program. At this point, you’ll probably see a simplified human figure standing on a blank gray plane.

The file will only have one layer, called “Layer0”. Add a new layer - I call this “raster” since this is where you’re going to import the image you just prepared. Switch to the new layer by clicking in the box to make it current. For some reason, SketchUp does not make the newly created layer active, so you have to do this manually. You can move the imported image to the raster layer later if you miss this step.

Layers are used in SketchUp to control what is visible, so if you’re going to use a lot of things that dramatically slow down the rendering process – such as three dimensional plants – you’ll want to put these items on a separate layer that you can hide until you’re ready to produce your image files.

Zoom out so that the human becomes relatively small, then import the image from the File menu. SketchUp can take some time processing the image where nothing appears to be happening, so be patient. Eventually your image will appear. Move the mouse to select where you want to place the lower left corner of the image, then click to “glue” the corner of the image to this point. Moving the mouse up and to the right will now cause the image to grow or expand. Move the mouse out until you feel that the scale is somewhat close to reality based on the relative size of the man in the model.

Now, it’s time to set the scale to something close to what you intend. It will always be a few inches off since the image won’t be as clear as it was in the original file. Select the Measuring Tool, click on the “zero” point in your bar scale. Without clicking, move the mouse to the end of the bar scale, at a known distance from the zero point. Click on this point. Immediately type the distance, for example 40’ (normally there won’t be inches in your bar scale, but if there are you would type 40’6” to add the inches). Once you type the distance and hit return, a window should open asking if you want to resize the model. Click OK and the model will set itself to match your bar scale. Note the warning text about components already in the model not being resized. That is why it’s necessary to start with a blank file and add everything after you’ve imported your sketch.

This is a good time to tell SketchUp where North is in your model, so you can check where the shadows will fall at a given date and time of the year. Zoom so that the north arrow from your sketch is visible. Open the “Model Info” window and select “Location”. Pick your city from the pull-down menu. If no city close to your project location appears, you can enter GPS coordinates (you can get these from Google Earth from the site address). Click on “Select” at the bottom of the window under “Solar Orientation” to set the direction for North - SketchUp will show your image, and all you have to do is click once at a start point on your north arrow, then again to set the relative direction.

Change your active layer back to something other than “raster”, typically “0”. Start tracing your design using the line, arc, circle, etc. tools.

This is where knowing two more things will save you a lot of trouble later. Group single, unique objects so that they don’t combine with their surroundings and can be edited separately. Typical things to group are buildings and features that are more or less monolithic like outdoor fireplaces. Make everything that repeats into a component. Good objects for components include posts, columns, beams, fencing, chairs - anything that will appear at least twice.

The fastest way to group something is to draw its outline with the line and/or arc tool. When the polygon is complete, SketchUp automatically fills it with a shaded color. Right click on the inside of your element, in the shaded area. A pop-up menu will appear with the option “Select Bounding Edges”. Select this, then immediately group the selected elements. This will prevent the ground plane from “sticking” to your element, allowing you to move it without distorting or warping ungrouped things that touch them.

Like groups, components act independently of their surroundings. Unlike groups, editing or modifying one instance of a component - a column, for example - edits all other instances of that component. Making one column ten feet tall instead of eight makes all of them ten feet tall, for example. You can think of components as editable clones. You create them by converting a group to a component, or by selecting objects as you did to create a group but instead selecting “make component”. The latter process requires you to name the component.

The beauty of working with components is that you can create one post or column, make it into a component, and automatically modify all the objects that are supposed to be identical.

Remember too that sets of components can be grouped, and components can contain components. So, if you’re building a shade structure, the structure can be a group so you can position all of its elements easily. The columns, beams, joists and lath will each be a component. Double clicking on the structure will then allow you to move its components. Double Clicking on a component will let you edit it - change its dimensions, add ogees, apply a texture, etc.

I tend to trace everything in one plane before moving into the third dimension, starting with the building. I group buildings, walls, etc. while they are still two dimensional since it’s much easier to select them at this time. Double clicking on a group or component makes it editable; clicking outside the group or element de-selects it.

Once object footprints are grouped or made into components and the ground plane is traced out it’s easy to use the push/pull tool to transform them into three dimensional objects. A few clicks of the paint tool and you’ll start to see your design emerge from the screen.

If you want a very sketchy look, and your site is flat, you can even leave the raster sketch to show the ground plane and just model your three dimensional elements. If you didn’t color your sketch, use the “Hidden Line” option for rendering under “Face Style” in the “View” menu. This will make the model black and white, and you can select to show or hide shadows at a given date and time. This is a great approach when you’re under a tight deadline and don’t have time to construct an elaborate model.

Once you’ve become proficient with these concepts, you will be amazed at how quickly you can generate a basic three dimensional model from your sketch, select the best views and create accurate perspectives to show your clients.

About the Author
A native Californian, Mike first earned a degree in environmental studies from UCSC, then went on to get a masters degree in landscape architecture from Cal Poly, Pomona. He served as president of the California Sierra Chapter of the American Society of Landscape Architects (ASLA), and was the group's webmaster until they decided that they no longer needed a web site. Mike is currently a member of the Association of Professional Landscape Designers (APLD).