This paper introduces a framework for selectively refining progressive meshes (PMs) based on changing view parameters. The authors define efficient refinement criteria involving the view frustum, surface orientation, and screen-space geometric error. An incremental algorithm is developed to adapt the mesh refinement according to these criteria, exploiting view coherence and supporting frame rate regulation. The algorithm is found to require less than 15% of total frame time on a graphics workstation. Smooth visual transitions (geomorphs) can be constructed between any two selectively refined meshes. The framework is effective for height fields, parametric surfaces, and general meshes, offering more accurate approximations than existing schemes. The paper also discusses the implementation details, including data structures and the generation of triangle strips for efficient rendering. Experimental results demonstrate the effectiveness of the framework in various applications, including terrain rendering, parametric surface tessellation, and general mesh refinement.This paper introduces a framework for selectively refining progressive meshes (PMs) based on changing view parameters. The authors define efficient refinement criteria involving the view frustum, surface orientation, and screen-space geometric error. An incremental algorithm is developed to adapt the mesh refinement according to these criteria, exploiting view coherence and supporting frame rate regulation. The algorithm is found to require less than 15% of total frame time on a graphics workstation. Smooth visual transitions (geomorphs) can be constructed between any two selectively refined meshes. The framework is effective for height fields, parametric surfaces, and general meshes, offering more accurate approximations than existing schemes. The paper also discusses the implementation details, including data structures and the generation of triangle strips for efficient rendering. Experimental results demonstrate the effectiveness of the framework in various applications, including terrain rendering, parametric surface tessellation, and general mesh refinement.