To make the videos that I’ve posted this week, prepare for live demos, and work on new tutorials, I have spent a lot of quality time in Wonderland, Google SketchUp, and the Google 3D Warehouse. As some of you may know, SketchUp was originally designed as a tool for architects and engineers. Google bought the company that created SketchUp in 2006 in order to provide a free tool for people to model buildings for Google Earth. What’s significant is that SketchUp was not originally designed for real-time environments like Wonderland or Google Earth. That means that many of the SketchUp models you find in the 3D Warehouse will not perform well in Wonderland. They are made up of too many polygons, which makes it difficult for the Wonderland client to draw them quickly.
Identifying Appropriate Models in the 3D Warehouse
After experimenting with importing lots of different models from the 3D Warehouse into Wonderland, I learned that the models that work best in Wonderland are those created specifically for Google Earth. You can identify these by the blue ribbon in front of their name. Here’s a random example:
The blue ribbon designation means that someone from the Google Earth team hand-selected the model for inclusion in the Google Earth 3D layer. For excellent performance in Wonderland, there are two other factors to consider in addition to the blue ribbon. First, look at the “Model complexity” rating in the lower right corner. Models with a “Simple” rating work best. Then click on the “Download Model” button and look at the file sizes. Anything under 1MB is likely to work extremely well. If the file is over 2MB, you will probably start to see some performance impact.
To find simple complexity Google Earth models, use the advanced search page.
Enter your query, and in the “Item type” section, select complexity “simple” and file type “Google Earth (.kmz).” Then check the first two check boxes in that section. What’s amazing is that there are over 30,000 models in the Google Earth 3D buildings layer that meet these criteria. For example, I found this model of the Parisian Palais de l’Élysée as well as an attractive red sculpture model which we used as a backdrop for this week’s staff meeting.
Note that when you bring models like this into Wonderland, they may look too dark. You can fix this by right-clicking on the model and selecting “Properties” from the context menu. In the “Model Component” property sheet, uncheck “Lighting Enabled.” This restores the original SketchUp lighting. To learn more about positioning your models in the world, refer to the Assembling Worlds tutorial.
One unfortunate aspect of the 3D Warehouse is that Google treats geo-located models differently from objects that don’t have a location. This means that small models like tables, chairs, lamps, etc. do not have the Google Earth (.kmz) formatted files associated with them, nor do they have a complexity rating. The only guidance you have about whether or not the model will work well in Wonderland is the file size of the Sketchup (.skp) download. The same rule of thumb applies – the smaller the file size, the better.
If you want to try a model that does not have a .kmz version listed in the Downloads section, simply download the .skp file for the most recent SketchUp version, open it in SketchUp, and select File –> Export –> 3D Model… Make sure the “Google Earth File (*.kmz)” format is selected and save the file. This will generate the .kmz file you need to drag and drop into Wonderland.
When you are adding models to a Wonderland world, it’s a good idea to show the FPS (frames per second) meter (Window –> FPS Meter).
In this example, notice in the middle how the frames per second dropped dramatically. That happened when I turned my avatar to look at some trees with very high polygon counts. Each time you add a new model to the world, face the model and check your meter. If your frames per second drop, then the model may not be suitable for use in Wonderland.
SketchUp Guide for Creating Your Own Models
In researching how Google Earth modelers manage to create fantastic-looking models of large buildings that are often under 1MB, I came across an extremely helpful reference that Google has put together for people creating models for Google Earth:
I would encourage everyone who is creating their own models using SketchUp to read this document carefully. Let me give you one tip from the document that I have found particularly useful. When you create your own textures, you should export them from your graphics editor (eg, Adobe Photoshop Elements) for the web in PNG-24 format. This format does the best job with transparency and small file size. This has allowed me to create some nice-looking skyline models shown here in Wonderland:
You could model these skylines in Sketchup by applying the texture and then tracing the skyline and cutting out the sky parts. That would create a model with a huge number of polygons. Instead, using a transparent PNG-24 texture, as recommended in the “Modeling a City” guide, I was able to create an extremely simple model with interesting contours.
In my next blog post, I’ll describe how you can make one of these skyline models for yourself.
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