Using billboarding for in-game UI displays
It is quite common in games to have outdoor scenes with a lot of vegetation, be it trees, bushes, ferns, or a bit of everything. At first sight, these might look like complex assets to optimize and render, since you have all these leaves to show everywhere, requiring a high enough density for the player to really feel the foliage volume... but that’s where the trickery comes in!
To fake this effect of leaves all around you without having to model millions of polygons of foliage, game creators have developed a nice technique over the years: billboarding.
In short, this shading ruse allows us to have some objects face the camera at all times – for example, the leaves in our trees – and thus, use just an image instead of a heavy 3D model. In a completely different context, billboarding can also be applied to extra-diegetic elements such as pickups and UI so that they are more readable in the scene.
In the next sections...
