I'm surveying an area and have a z-value attached to each polygon. In comparison to the area I'm studying the polygons are quite small. What I'm trying to do is show the distribution of this value. I've been researching IDW, heatmapping and Kriging but none of these seem to quite fit the purpose. The main problem I've come upon so far is by using the centroids, which aren't evenly distributed, I am analysing more that spatial distribution than the value distribution. I'm hoping to produce a raster output, purely on a visual basis as they show the spread clearly. If anyone has any suggestions of tools, techniques or even advice on where to start looking, I would be more than happy for your help. I'm using QGIS mainly, but also have access to ArcGIS and some other pieces of software.