This paper proposes a method of rate-distortion optimisation of an algorithm for compressing dynamic 3D triangle meshes. Although many articles regarding compression methods for this kind of data have been published in the last decade, the problem of rate-distortion optimisation has only been addressed by a very few of them. An exhaustive search method, where a grid of parameter configurations is used in the compressor and only the configurations producing good results are selected, is still widely used even though it requires a number of tries exponential to the number of parameters. Our proposed method can find better solutions (i.e. closer to an optimum) in expected linear to quadratic time.