Resumen
The paper considers a task of real-time modelling of Earth relief based on detailed global height maps specified relative to the rotational ellipsoid (spheroid) WGS-84. The technology of adaptive tessellation of triangular patches on the GPU is proposed, which provides real-time construction of complex polygonal models of the Earth's relief. The technology includes the stage of dividing the visible ellipsoid into coarse patches (low level of detail) and the stage of their tessellation into triangles of the relief model, executed in parallel and independently on the GPU cores. The paper proposes new, distributed methods and algorithms to extract the patches needed for visualization of the current frame, to increase their level of detail in accordance with the height map and screen resolution, and to transform to relief polygons. The novelty of the work is that the tessellation of triangular patches of an ellipsoid is based on the original scheme, which allows relief areas that require high level detail to be effectively localized. This significantly reduces the time of relief model construction and improves the quality of the created images.The developed technology, methods and algorithms were implemented in program modules and tested in the visualization system of the Earth?s virtual surface. Modelling and visualization of the Earth's relief was carried out with a detailed texture of the underlying Earth's surface and the calculation of illumination taking into account the atmosphere. The approbation was carried out in a virtual space scene comprising a detailed polygonal model of the International Space Station (ISS). The obtained results confirmed the adequacy of the proposed solution to the task and its applicability for building of space video simulators, virtual environment systems, virtual laboratories, etc.