Is it possible to add hatch style in Cesium3DTileStyle or in Cesium3DTileset

I have buildings that are added through Cesium3DTileset and I want to set hatch (stripe, grid) to them.

Depends on many things, but if your tilesets have properties that match the hatch, then it’s a matter of creating a colorizing ruleset. You can also look into the new color bands added a few months back. But if your tileset isn’t linked to the hatch, you can always drape a polygon over it with a material that matches whatever you’re trying to do.

I’d say draw a simple sketch of what you’re trying to achieve so it’s easier for us to imagine and help you out.