how to make only B3DM file only of the particular region ?

1. A concise explanation of the problem you’re experiencing.

please anyone tell me how to create a B3DM file only for particular region ?

like in the gltf we can make a objects(buildings) using sketchup tool .

like a same way how can I make this objects and create a b3dm file of the particular region .

please help.

2. A minimal code example. If you’ve found a bug, this helps us reproduce and repair it.

3. Context. Why do you need to do this? We might know a better way to accomplish your goal.

4. The Cesium version you’re using, your operating system and browser.