Applying Perspective to the Ground Plane

The last example deliberately left out an important aspect of most images: the ground plane. Since the ground plane recedes into the distance, we cannot simply blend it with a solid color to achieve natural atmospheric perspective.

Let’s take a look at another example. This time we have a sand-colored checkerboard desert floor, some sand dunes, and some cacti.

First, using the same steps as before, let’s use layers of sky color to blend the dunes and cacti:

This is already looking much nicer. The dunes are pushed toward the horizon, and the closer cactus is brought forward. However, we still need to bring the ground itself into perspective. We can do this with a simple variation of the same technique.

First, make a new layer in front of the ground layer. Fill this layer with a gradient that starts with a fully opaque sky color on top and ends with a fully transparent sky color on bottom:

NOw use Layer->Create Clipping mask to limit the effects of this layer to the ground plane.

Now the transparency of the gradient needs to be adjusted to be consistent with the thickness of the atmosphere in the rest of the image:

There we go! We’ve made a nice, dusty, desert scene.

Atmospheric Perspective in Games