Maya 2017 Update 3 added the World Node and Placer node to Maya’s motion graphics toolkit. The placer node allows you to add elements to the surface of an object by clicking or brushing them on. Both the world node and placer node are a great way to populate scene quickly and easily — Perfect for set dressing and creating environments.
You really need to see how beneficial the placer node can be for set dressing scenes. Watch 3D artist Mao-Lin (Khitan Digital) as he creates and populates an environment using Arnold Stand-ins with the placer in MASH. Arnold Stand-Ins are a feature that allow you to work with lower relation elements in your scene, but will inevitably draw the higher resolution geometry data when rendering.
Mao-Lin is using the hotkeys to modify how the elements are being placed. You can hold M to drag scale or rotate an object. The J key will rotate or change the direction of the object. You can also hold Shift/Alt to increase and decrease size after scattering. “The performance is very good and rendering are fast I can scatter and paint almost in realtime” Mao-Lin mentions.
Watching this makes me want to dive in and make some worlds!