I know I can turn it into a union and then put it in blender and make a mesh, but If i do that the stuff inside the little house will still be there. I only want the outside to be present
Another problem is that how i would keep the design of the house, if i use the material it’ll apply to everything because… its one mesh
The idea seems quite unreasonable on why’d you want to transform it to a mesh.
Regardless of it, IP in Roblox caught risk of you potentially getting warned or banned for re-using Roblox Materials(as you import the model back in).
As for the problem itself, I don’t think you have a choice. Either you learn Unions and PreciseConvex or Blender.
As for the importing as one mesh, there is an option called OBJ Groups that allows you to import as a single .obj file multiple meshes at the same time in their own position.
This can only be done using Blender of just shaping the house the way it should be to load in as a mere part that is full.
I cannot say what you define as a full house.
I mentioned previously about the IP of Roblox that I’m not sure if you can use the Roblox Textures (as you export and import the model for it to be a mesh). I don’t think there are other ways, I haven’t dug that deep to Model loading properties.