Product Reviews

SketchUp 2.1 did something that no other program came close to - bridging the divide between 2D and 3D drawing. Moreover, it did this in such a simple, elegant and efficient way that it was ideal for exploring and presenting 3D ideas. You'd think this was revolutionary enough, but now version 3 is breaking even more ground.

The inference drawing system that underpins SketchUp, for example, has been notably enhanced. This intelligently anticipates your intentions, checking possible 2D line positions against the main axes and the existing model, so you can draw interactively in 3D space; for example, creating a cube in just a few strokes. But now this system features new equidistant and tangent inferences, which are especially useful for drawing chamfers and fillets. Making life even simpler are SketchUp's Push-Pull, Move and Rotate tools, which let you interactively extrude, reposition and rotate selected faces within 3D space simply by dragging.

It's a brilliant system that lets you quickly build up complex models, but there's one major drawback: all lines/edges must be straight and faces must be coplanar. It's not a crippling problem, as you can simulate curved edges with multiple line sections (a 'polyline curve') and curved faces with multiple polygons. However, this has downsides when it comes to editing and output, as drawings with curved faces, such as columns and domes, end up looking faceted.

But now @Last Software has come up with a typically ingenious workaround. When you add a polyline curve using the Arc or Circle tools, SketchUp remembers the higher-level shape information, so you can retrospectively change the diameter or the number of line segments. What's more, if you push or pull any curved or freehand shape to create a curved face, these lines are automatically 'softened', so they only appear in profile, all internal lines are hidden and the undesirable faceting disappears. You can also 'smooth' curved faces by rendering adjoining faces with a smooth tonal gradient. This again improves output quality, although SketchUp is designed to produce sketches rather than photo-realistic renderings.

Its output might not be photo-realistic, but that doesn't stop SketchUp packing a punch when it comes to formatting. The Paint tool lets you instantly apply any bitmap texture to your model's faces and you can then edit them in situ

ADVERTISEMENT

in real-time, say to change colours or scale. Plus, there's now the ability to set your material's opacity level, so you can create realistic liquids and glass - particularly important for SketchUp's target audience of architects.

SketchUp is ideal for exploring 3D ideas, but these ideas also have to be presented as effectively as possible. SketchUp 2.1 offered a number of unique features for this, such as adding hand-drawn jitter to lines and accurate shadows based on location and the time of year and day. However, there was one obvious omission: you couldn't annotate your drawings because SketchUp didn't support text.

Now, of course, it does and the SketchUp approach is typically innovative and creative, with two distinct types of text. The first is 'screen' text, which remains fixed to a point on your screen and is ideal for adding titles and captions. Then there's 'leader' text, which is linked to a face on your model, either implicitly or via an arrow. As you rotate your model's view, the leader text follows its object while maintaining its orientation to the screen. When the leader arrow becomes obscured, its associated text automatically disappears. This could be used for labelling and dimensioning, although if you're adding linear distances you'll be better off with the new dedicated Dimensioning tool.

Seeing your drawing's annotations and dimensioning update in real-time as you change the view is impressive, assuming you have an OpenGL graphics card and reasonable processor. But even more striking is SketchUp's TourGuide technology, which lets you use that as your presentation rather than a static sketch. You can set up pages based on current camera position, view settings, shadow settings and so on, and when you swap between pages SketchUp automatically interpolates between the two views smoothly. Not only that, but it's also possible to output your TourGuide presentation to an AVI file for delivery on CD or DVD, or even via the Web.

For the latter, you can also output your scenes to VRML (virtual reality markup language), so users may interactively explore your work via a supporting player. Plus, for more traditional 2D output, SketchUp supports a reasonable range of static bitmap formats, including JPEG, TIFF and EPIX for further processing in Piranesi (see issue 105, p108). Bitmaps provide the richest output, but if you're going to work further on your models then vectors are preferable, even though formatting information such as textures and shadows is lost. SketchUp 3 also now provides 'filled polygon' output of your current view to EPS or PDF format, which is great if you're trying to produce 3D work in Illustrator. Then, for more technical control, you can also output to the DWG or DXF CAD standards, or even output to 3DS to continue your work in a dedicated 3D modeller.

From original drawing through to final export, SketchUp 3 creatively pushes back the boundaries and enables you to do the same.