There are a number of features & design considerations in the Java 3D API that enable very good performance across a wide range of compute environments and applications.
View frustum culling will render only objects which are visible, and will not attempt to render off-screen objects.
The Java 3D API automatically takes advantage of multiple threads and processors whenever available, and is designed for parallel execution at all levels, including rendering.
You can compile portions of your scene graph for better performance (compiled-retained mode) and can interrupt the rendering cycle (immediate mode) when needed.
As you get closer to an object, you can have the Java 3D API automatically substitute a higher-detail model, as many times and at any distance you desire.
The Java 3D API uses low-level, native libraries to “talk to the hardware”. The reference implementations use either OpenGL or Direct3D, the most popular interfaces to graphics cards. This enables you to get native hardware acceleration when manipulating 3D models.
The Java 3D API can optimize your scene graph for maximum performance on the target platform, freeing the developer from having to tune the application for each platform.