We present a framework for rendering very large 3D models at nearly interactive rates. The framework scales with model size. Our framework can integrate multiple rendering acceleration techniques, including visibility culling, geometric levels of detail, and image-based approaches. We describe the database representation scheme for massive models used by the framework. We provide an effective pipeline to manage the allocation of system resources among different techniques. We demonstrate the system on a model of a coal-fired power plant composed of more than 15 million triangles.