how can i add a cost map?

edit

HI, i'm studying about octo-mapping.

when my drone(using d435i+t265 camera) scanned a room, the point cloud's shape is not clean.

i want to add a cost map for limit a scanning area which looks like my room's shape.

I'd like to add a map of the shape of my room to get the result in a non-scattered form of point clouds.

Like the point cloud that a drone gets when drone perform slam in a gazebo simulator, is there a way for a drone to get a clean point cloud in a real environment?

I want to visualize a clean point cloud in rviz.

Thank you.