1. A computer-implemented method for predicting whether a point on a computer-generated surface is adjacent to laminar or turbulent fluid flow, the method comprising: obtaining, using a computer, a plurality of instability modes, wherein one or more mode parameters define each instability mode; obtaining, using the computer, a vector of regressor weights for a set of known instability growth rates in a training dataset; for an instability mode in the plurality of instability modes: determining, using the computer, a covariance vector comprising a covariance of a predicted local instability growth rate for the point with respect to the set of known instability growth rates in the training dataset; and determining, using the computer, a predicted local growth rate at the point for the instability mode using the vector of regressor weights and the covariance vector; and determining, using the computer, an n-factor envelope at the point using the predicted local instability growth rate, wherein the n-factor envelope is indicative of whether the point is adjacent to laminar or turbulent flow.