How it works?

This subpage describes in detail and methodically what assumptions should be met to prepare the camera to work with Motioncube interactive projection systems (floor, wall, or table). Although a thorough analysis of the principles presented here is not required, it can make it much easier to understand how and why interactive projection is possible and what issues in particular are relevant.

General guidelines

Two key requirements for the camera that will be used for the Motioncube projection system:

1. The camera should not see what the projector is displaying.
2. The camera should see what is happening on the projection surface in the interaction area, regardless of the lighting conditions, such as time of day, etc.

Explanation:

• Ad. 1 - The camera cannot see what the projector displays, as this could lead to a situation where animations displayed on the projection surface would trigger a motion detector, i.e. an algorithm that detects movement in the image from the camera. Due to the fact that the projector displays the image using light from the visible spectrum, it is enough to block the possibility of observing light from this range by the camera. Another solution is to use depth cameras, where the image reflects the distance from the camera.

• Ad. 2 - From the point of view of the camera, external lighting conditions should not matter. For the camera, the interaction area should always be uniform, regardless of lighting conditions.
  • For motion interaction, the camera should see the projection area as uniform and bright so that even at night or in a dark room, the camera can see what is happening in the interaction area. To meet this requirement, you will probably need to additionally illuminate the interaction area using an external or integrated with the camera infrared light source (read more about IR illuminators). In the case of depth cameras, additional IR illumination is not required, because such cameras have built-in light sources that ensure their ability to work even at night.
  • For interaction with IR pens, the camera should see the projection area as uniform and dark for the Motioncube light point detector to work properly. Additional IR illumination for interaction with IR pens is not applicable.