data-position

<mr-entity data-position="0 -1 0.5" data-rotation="90 -30 180"></mr-entity>
<mr-light data-position="0 -0.1 0.15" color="white" intensity="0.5"></mr-light>

Position can be attached to an mr-entity using data-position, it has a specific 3D value:

data-position

Sets the position of an entity in the 3D space, relative to its parent.

Value: a string of 3 numbers in meters separated by a space.