CityJSONEditor very slow on thousands of objects

[paleajed]

Hello,
I have been testing your addon with a dataset containing around 7000 buildings, all textured (7000 local appearances). When running the addon, at first it is quite fast at processing the buildings but rather soon its pace grinds almost to a halt. I suppose this is because every single building is made into a Blender object, slowing down Blender itself. I have been waiting over six hours, and still it isn't finished.
I tried loading separate tiles into Blender using your addon, but when I try viewing the textures, it slows down because of an enormous amount of shaders compiled. After importing some tiles, Blender chokes and crashes.
I am under the impression that both importing of bigger datasets and the implementation of texturing during the import could be made much more efficient. I tried using 3DCityDB to convert my original CityGML dataset into COLLADA and the textured geometry it ends up with is most nimble when viewed in Bllender, and importing is really fast. But then there's other issues with this COLLADA import making it unsuitable for my purposes. Really I am only trying to get a CityGML into Blender; your addon could be key to this, but then it needs streamlining... Or maybe this is an issue with my specific dataset?

[gdmhrosch]

Hello paleajed,
it is true, that the addon creates blender objects for every building and in fact materials for every individual surface. Your dataset is most likely not the problem.
Unfortunatly I am not very suprised by the troubles you have encountered because the addon isn't really intended for the display of many buildings but rather for the specific purpose of editing of individual ones or very small groups at a time.
I'm absolutely sure that there are a plethora of problems concerning the efficiency of a lot of operations in the code and i have been locking into some of them but this is my first addon for blender (as a side project) and I'm quiet happy that it does what it is supposed to do in the first place.
I can think of some things that might massivly improve performance like a propper texture mapping (UV unwrapping) but implementing this with the way CityJSON and its textures are encoded seems very difficult and extensive, in my opinion at least.
Having a way to display large scenes would definitely be great but I'm honestly not sure if this is possible with the way the addon is structured right now.
Nonetheless thank you for your interest.