Product Reviews

LightUp takes the technology used to speed up games and applies it to rendering in SketchUp. Basically, games use a technique called 'baking', whereby textures, shadows and shading aren't calculated on the fly but are pre-calculated and then 'baked' into an object's geometry as a single applied bitmap. This has the advantage of keeping a highly realistic appearance, but removing the enormous calculation overhead.

LightUp installs as a plug-in and posts three buttons: Preferences, Light Inspector and TourTool. Clicking on the TourTool button is enough to generate a render, although LightUp defaults to relatively low settings at first to allow you to subsequently finetune the output. All the calculation of surface properties and the baking of the textures onto the model is performed automatically. If you've ever tried to do this by hand, you'll know this is quite a feat.

The renders can be subsequently refined by setting either a multiplying factor (for the number of samples taken) or a sample distance (based on the overall size of the model). As these are increased, shadows, for instance, will become more defined, but never hard edged: LightUp produces realistic, soft-edged shadows. It also handles transparency

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and reflection much better than SketchUp's own 'Sketch' renderer. It's also possible to set glass to be reflective. You need to supply a component called an Irradiance Cache to the object you want to be reflective, and two textures: one with the texture name and another with _uvlmap appended to the name. This takes a bit of getting used to, and the supplied documentation is a little cursory, although there's also a user forum. Reflection can be applied to either solid or translucent objects.

LightUp uses SketchUp's sun position, but you can also define your own lights by defining a material and appending _lightup(emitter) to its name. This effectively turns the surface into an Area light. Colour is taken from the SketchUp texture colour, and other attributes such as Power and Spread Angle are accessed using the Light Inspector tool.

LightUp takes a very interactive approach to its renderings: once rendered, the whole scene can be navigated using the LMB (orbit), shift-LMB (pan) and scroll wheel (zoom) in real time, even on quite complex scenes. These walkarounds can be captured in real time, but only as a series of images, so you'll need to segue them together in a video editing program.

Rendering time is also dependent on the complexity of the scene. The most complex that we tried (about 15MB) took around 40 minutes at high settings, which is still faster than doing it by hand. LightUp also uses a cache so it can be re-calculated in around 15-20 seconds. On some scenes, we also got persistent black faces on some objects. The only way to clear these was with a restart.

LightUp is a program that's unique in what it does for SketchUp - in some ways, it's little short of magic. There are a few rough edges, but we'll be eagerly awaiting to see what each successive release brings.