Are you a user of many SketchUp Extensions? If you're a SketchUp Pro user, we'd like to recommend one that's a great companion to Visualizer: Solar North, actually created by the SketchUp team themselves.
What it does is pretty simple -- it lets you set the direction of "north" relative to the model. This can be a huge time saver when looking at house plans or any other model where the position isn't always locked down (you wouldn't change the direction of the sun for, say, a model of the Vatican, but you might want to change it for a group of Alfa-Romeo's).
Without Solar North, to change the noon-time light direction you need to grab the whole scene and rotate it. With Solar North, you'll get a handy pair of set-north tools (they work like the SketchUp Rotate tool) that let you choose the compass direction and vertical angle of the sun quickly and interactively, without needing to move the model or camera at all.
Here's a pair of Visualizer images showing the Wikihouse Studio, modeled by Ollie Plant and shared on the SketchUp 3D Warehouse. At top, the windows are north-facing. A Quick twist of the Solar North set-sun tool and we can see that VIsualizer instantly shows the exact opposite case, with the windows facing south -- which would you prefer?
Ruby Expert Dept.
Yes, you can also adjust the angle with a terse one liner like so:
Sketchup.active_model.shadow_info['NorthAngle'] = 45