Assets are placed in the scene by creating a new asset element in the hierarchy and assigning an asset to that element.
Create an Asset Element
To create an asset element, you can use the element menu in the hierarchy. The element menu can be accessed by clicking on the 3 dots at the end of the experience root element. Open the element menu, select Create..., then select Asset.
When you create a new asset element, you will see its position gizmo appear in the canvas at the origin. This newly created element is known as an empty element because it has no asset assigned to it.
Assign an Asset
To assign an asset to your new element, you first need to choose which asset to assign. Navigate to the library panel and make sure the drop down is set to Assets. In the asset library you can find many public assets which are available for anyone to use, or you may upload your own assets.
Make sure the empty asset element is selected. Once you have chosen an asset, click and drag the asset to the Asset section of the inspector.
In the canvas a white bounding box will appear as the asset loads in. It may take several seconds for the asset to load into the canvas. When it is finished loading, a green bounding box will appear around the loaded asset.
Replace an Asset
At anytime, you can replace an already assigned asset by dragging a new asset into the Asset section of the inspector.
The new asset may take several seconds to load before appearing in the canvas.
Assign Assets in the Hierarchy
Alternatively, assets can be assigned directly in the hierarchy instead of using the inspector. Simply drag the asset to the element you wish to assign.
Remove Asset Assignment
To remove an asset from an element, simply click the X on the asset thumbnail in the inspector.
Removing an asset assignment this way only removes the asset, but the asset element still remains in the canvas and hierarchy.
Delete an Element
To delete an element, you can use the element menu in the hierarchy. Click on the 3 dots, select Delete, then select Delete again from the confirmation message that appears.
You can delete an element with or without an asset assigned to it. Deleting an element removes it from both the canvas and the hierarchy.