When adding terraces to a landscape, the modulation is not linear. If you plug a linear gradient into the terrace device as a modulator the resulting terraces curve instead of being linear. Is there a workaround for this?
hmm… Can you compare the result with the linear gradient to the point as to subtract on from the other? How non-linear is it?
Or even better do this: use a North South gradient and terrace that with a modulation given by an East-West gradient. That should make a nice curve-ish shape along the original gradient terrain. What shape does that resemble you? 