Optimize smoothness of synthetic model by decimating number of traces

[EvanBianco]

For our current synthetic section dimensions, the max number of traces in the spatial section should be around 100 or so. Any more than this and we see excessive jitteryness that isn't seen on other seismic models. We might need to make this an argument for the user, but we should be able to treat it as an adapative parameter based on input and display dimensions.