Enhance and customize the visual elements available in SketchUp. Integrate the plug-in for adding lighting sources and effects to your existing projects. Calculate and adjust the lighting model, backdrops, reflections, and other elements in real time. Save and preview editing results.
Our website provides a free download of LightUp 4.2.3. The actual developer of the program is Adam Billyard. The LightUp installer is commonly called LightUp.exe. The software is included in Photo & Graphics Tools. The most popular versions among LightUp users are 4.2, 4.1 and 3.0.
From the developer:
LightUp is a plugin for SketchUp that adds realtime lighting of your model inside the SketchUp window. You can add light sources to your model, backdrops, reflections, and immediately see the results without exiting SketchUp. When its done, you can export your lit model to a compressed file containing your Model, textures and Scenes and share it with others using the free LightUp Player or LightUp Web Player.
You may want to check out more software, such as Christmas Tree Light Up, which might be related to LightUp.