Quote - The background: in the Assemble room click on Scene and see what comes up, above it - it's either a gradient background/drop or the ground from a sky Atmosphere. You can switch either of those off easily enough.

Click on Scene in the Assemble Room then Atmosphere it depends if you are using 'Sky' or 'Realistic Sky' on your ground control options.

If you are using a 'Sky' the ground will stay on but you can edit it a bit by selecting the Sky 'edit' button. Play around with the sliders and see if you can lessen the ground effect for your scene to something you may be satisfied with for your scene.  Background or Backdrop should be set to none by default, thus there is nothing to turn off (the Sky 'Edit' options is where you would minimize the ground effect).

However If you are using a 'Realistic Sky' when you select the Atmoshpere tab you will have the option to turn off the ground. Then all you have to contend with is the horizon. To get the effect you are after against the sky backgroud you may need to adjust the position of your figure and camera angle.

Good Luck,
Stan