I am trying to patch a surface of points together to replicate the difference in density between downtown seattle and its surrounding built environment. I have imported the heights and footprints of every building in seattle and have created a point at the center of the roof of each building. However, an issue came up where some of the points are randomly very low on the z axis (at the building footprint instead of the top). This is creating a crazy patched surface which is not smooth at all, and not what I want. As a resolution, I have tried to sort and eliminate all of the points which are below 100 on the z axis. I have tried a number of different ways to sort the lists and all attempts have lead me to only points on the Z axis, therefor I am not able to patch the points.
Here is a screenshot of some of the failed definitions I have tried;
I have also attached an image of what the patch looks like without deleting the low points;