1. A method, comprising: receiving a three-dimensional (3D) triangular mesh comprising a plurality of triangles; creating a two-dimensional (2D) triangular map for each triangle of the plurality of triangles, wherein the creating comprises: generating a plurality of sub-triangles within each triangle; recursively repeating the generating for each sub-triangle until reaching a depth level, wherein the depth level depends on at least one of a target resolution or an entropy threshold; sampling a field at a respective point within each of a plurality of leaf nodes, wherein each leaf node of the plurality of leaf nodes represents one of the sub-triangles at the depth level; calculating a field value for a plurality of non-leaf nodes at each level of the recursion until reaching an overall field value for a top-level triangle of the 2D triangular map; and storing the sampled and calculated field values of fewer than all of the nodes; and specifying the field over the 3D triangular mesh, wherein the specifying comprises: reading the stored field values; and estimating the field values of ones of the nodes that were not previously stored.