I am rendering a TopoJSON document, created via mapshaper.org from a shapefile, on Cesium. That works fine for all geometries except one. I have tried re-creating the TopoJSON document and re-editing arcs manually but I always end up with different geometry artifacts.
To me, it looks like some of the arcs have an incorrect coordinate in between, which leads to the self-intersections. But I am not able to debug the coordinate in question.
Also, when I remove arcs from the polygon manually, I end up with similar artifacts at different locations, which seem to be completly random.
Using "Check validity" in QGIS does not give me errors or self-intersections for the initial geometry, neither in the shapefile nor in the TopoJSON.
EDIT: I have displayed the outline of the polygon and it seems that the artifacts do not have an outline, which leeds me to the conclusion that this might be a Cesium rendering issue rather than an issue with the coordinates in the TopoJSON document.
Does anyone have an idea, how to debug or correct the polygon geometry?
Cesium rendered TopoJSON:
TopoJSON with some removed arcs: