Leona Kaneshiro

I am learning to model using osm files.
I generated several buildings using osm files and the building tools, and when I exported them to hda files and then imported them into Unreal, the individual models became very small, but the models in Houdini were positively lit. And there are some places where orange cubes appear and I don't know what they are.
I don't know how to solve this problem, if anyone knows please help me, thanks!