A few years ago, Adobe made a rather half-hearted entry into the 3D market with a program called Dimensions. Rather than being a full 3D modelling tool, Dimensions allowed you to work with 2D drawing tools and then convert your artwork into three dimensions.
SketchUp, as seen on the Steve Jobs keynote at Apple Expo Paris, takes a similar approach, but does it rather more successfully. It provides users with a basic selection of 2D drawing tools for creating straight lines, curves, and geometric shapes such as rectangles and polygons. Those shapes are then extruded into 3D and used to construct 3D designs.
It’s important to realise that SketchUp isn’t a CAD tool – in fact, the developers, Last Software, refer to it as ‘anti-CAD’. The aim is to provide a quick and easy way of creating 3D sketches and visualizations without the need to master complex and expensive CAD software.
The key to working in SketchUp is its ingenious Push/Pull tool. When creating a simple 2D shape such as a rectangle, you select the Push/Pull tool and then click on the rectangle to stretch that shape out into three dimensions. But instead of treating the resulting model as a single solid object, SketchUp treats it as a series of connected edges and surfaces. The Push/Pull tool and the other drawing tools can then be used to further modify those surfaces. If you use the Line tool to draw a line across one surface, this will automatically divide it into two separate surfaces, which can then be pulled apart with the Push/Pull tool for further editing.
SketchUp doesn’t provide the precision of a CAD program, but it’s possible to enter numeric measurements into a text box at the bottom of the screen, and there are a number of other useful options that help keep things tidy. If drawing lines close to each other, automatic guidelines appear on screen to help you align the end or mid points of lines, and lines drawn parallel to the x, y, or z axis initially appear in the same colour as that axis, so you can always tell if you’re slipping away from the parallel.
There are also some interesting lighting and shadow effects to help add a bit of atmosphere to your designs. You can actually set shadows and light to match the conditions in specific locations and at a particular date and time, such as 9pm on June 21 in Colorado. Oddly though, the designers seem to have missed more basic options such as the ability to manually reposition light sources. To do this, you have to use the time control to adjust the position of the virtual ‘sun’ overhead.
Another irritation is the fact that the Selection tool is rather limited, and selecting multiple surfaces or edges can quickly become a chore. It’d be nice to have better grouping and ungrouping options in order to speed up editing in more complex designs.
Ironically though, it’s SketchUp’s limitations that make it so easy to use. You can get started very quickly with its basic collection of drawing tools and then do all the important work by experimenting with the Push/Pull tool.
It’s never going to replace Alias|Wavefront Maya or Autodesk’s AutoCAD, but SketchUp’s quick-and-
easy visualization tools make it a useful complement to more specialized programs such as these.