If you've done a lot of work in SketchUp and use actual 3D models of trees, maybe you've noticed that these trees bog down your model - everything moves slowly. The solution for this is to use a 2D "face camera" tree, which is like a cardboard cutout tree that rotates to always face you, giving the illusion of being 3D.
Google provides a few schematic "face-camera" trees, but these don't look very realistic. You can use a digital photo to create your own trees, but this requires a good bit of photo trimming, which can be tedious.
Render Plus provides several types of SketchUp plug-ins (some free and some not) and they've just released RpTreeMaker. This is a FREE plug-in you can use to create fractal tree images, complete with realistic-looking trunks and leaves. You can adjust nearly every parameter a tree can possess: age, height, branch length, crookedness, leaf density, and much more. You can control the quality of the rendering as well: low quality makes a faster tree, and vice-versa. Once you complete the rendering of the tree, you insert it right into your SketchUp model as a component.
Here are a few trees and shrubs I whipped up in about 15 minutes:
(If you want to download the above model, click it to open its 3D Warehouse page.)
The plug-in is pretty easy to use, and rather fun to play with. You won't know exactly what your tree will look like until you insert it into your SketchUp model, but if you don't like it, you can erase it and start over, adjust your parameters slightly each time (RpTreeMaker starts from the last tree you made).
What's very cool about these trees is that you can (but don't have to) mask them for shadows. This means that the image will be created as if there is blank space between each leaf and branch, and the shadows will therefore be accurate. SketchUp doesn't do this on its own with alpha-transparent images (images that have transparent backgrounds), so the masking option is quite useful!
If you want to see some examples of RpTreeMaker trees and shrubs, you can get some of Render Plus's trees and shrubs in the 3D Warehouse.
Anyone can design anything in 3D! www.3dvinci.net