For our purpose, it is not necessary to immerse the viewer in a completely artificially created scene, but rather to expand the visual perception of a real situation in such a way that optically camouflaged small animals become visible. If one wants to add optical sensory impressions, it is called Augmented Reality (AR). 

The main difference between augmented reality (AR) and virtual reality (VR) is that reality is augmented (AR) rather than replaced (VR).

What exactly can this augmentation look like? It is additional information that is to be inserted into the user's field of view as seamlessly as possible - and again, the visual impression is then created as if the overlays are part of the perception of the real scene.

This information can take many forms: it can be text messages, images, directions, and even animated representations for computer games or assembly instructions. 
For our project, an augmented reality representation has the advantage that only a thermal image pointing to the animals needs to be added to our own visual perception. For our prototype, we therefore do not need an additional camera for the visible spectrum compared to the VR representation. 

Related" to augmented reality are "AR smart glasses", which usually superimpose information on one side of the field of vision, e.g. text messages or directional information.

We initially decided on a system that, like smart glasses, only displays the thermal image in one eye. The design requirements we set ourselves were that it should be possible to mount it on the side of a pair of protective goggles:

This is how it (should) work:

For the first tests, we looked for small color displays and a thermal sensor that were as inexpensive as possible.