I have problem make PolygonGeometry

I loaded the geojson generated by turf.js and generated polygons by adding the height of each to the position in the hierarchy of the generated polygons.

However, it renders an unwanted triangle at the beginning of the polygon.

Attached is a sandcatle with those coordinates.

https://sandcastle.cesium.com/index.html#c=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

Hi @Leafmire, this is an interesting display! I think what we are seeing in that screenshot is a triangluation problem. The heights are well-defined along the outside edge, but the heights in the middle of the shape are not defined, so the triangulation simply interpolates linearly between vertices.

Can you generate the positions with a smaller spacing in this part of the shape? I attached a rough sketch to show what I mean.