Two ways of rendering a regular terrain elevation grid using WebGL are considered: based on natural triangulation and that with preliminary smoothing of the surface. The natural one is built directly on the points of the original grid, which thus serve as the vertices of the triangular faces of the simulated surface. Pre-smoothing involves smooth interpolation, ensuring the continuity of the normal, over the given grid points. As a result, a more detailed triangulation is possible based on the calculated points of the interpolated surface. For the two proposed approaches, recurrent formulas for calculating the coordinates of vertices and normals necessary for the formation of the corresponding WebGL buffers are obtained; the advantages and disadvantages of the two ways are discussed. To identify the acceptability of conditions for natural triangulation, a number of numerical experiments were performed on the example of SRTM data using a specially developed WEB tool. The developed technological methods enabled integrating the Google map within a single tool and partially load the SRTM data corresponding to the selected area on the map, as well as vary the key rendering parameters.