  We demonstrate that the Ising model on a general triangular graph with 3
distinct couplings $K_1,K_2,K_3$ corresponds to an affine transformed conformal
field theory (CFT). Full conformal invariance of the $c= 1/2$ minimal CFT is
restored by introducing a metric on the lattice through the map $\sinh(2K_i) =
\ell^*_i/ \ell_i$ which relates critical couplings to the ratio of the dual
hexagonal and triangular edge lengths. Applied to a 2d toroidal lattice, this
provides an exact lattice formulation in the continuum limit to the Ising CFT
as a function of the modular parameter. This example can be viewed as a quantum
generalization of the finite element method (FEM) applied to the strong
coupling CFT at a Wilson-Fisher IR fixed point and suggests a new approach to
conformal field theory on curved manifolds based on a synthesis of simplicial
geometry and projective geometry on the tangent planes.
