Stalker: Clear Sky - Is Your System Ready?

Water Test

The following pictures compare the illumination quality at the maximum setting; the order is: static illumination, dynamic illumination of objects, dynamic illumination, extended dynamic illumination, and extended dynamic illumination of objects.

In this test scene, Stalker stands at the pumping station in the swamp and has free view of the water’s surface. These test images show the largest aesthetic difference by using the different illumination models. The camouflage net is only completely visible in static illumination mode (first picture). When using other illumination models, it almost completely disappears. The campfires in the background also can only be seen with static illumination (first picture) — when using the other illumination models, the flames are covered by fog or bushes.

When taking a closer look at the background, you see that the haze is missing with static illumination, which lets you see more trees on the horizon. This may be an explanation for the relatively low frame rate, because the difference between static and dynamic illumination is only 9%. You can see the largest visual quality loss in the water because the static illumination setting hinders all reflections, making the surface ugly and giving it a uniform pattern.

In images 2 and 3, you can see the differences between object illumination and normal illumination. With dynamic illumination of objects (image 2) the weapons shine on the wooden footbridge, although they are in the shadows. When using the dynamic illumination setting (image 3) the position of the sun changes, which you can see from the shadows. The weapons on the wooden foot bridge don’t glow anymore, but are illuminated by a global light source and now have shadows. Another difference is the bushes in the water: with object illumination they are bright; without, they are dark because they only get illuminated by a global light source.

It is hard to see where the performance loss between extended dynamic illumination and extended dynamic illumination of objects comes from. The waves on the water surface are a little softer, and many objects are further illuminated; the fog should be computed a little more precisely.

You can easily avoid static illumination, because the performance loss compared to dynamic illumination of objects is only 9%. In return for that small decrease you get water reflections, although the range of view decreases because more fog covers the horizon. In DirectX 10 mode (extended dynamic illumination) the visual differences between normal and object illumination are rather low, but the frame rate drops significantly. You should probably avoid the maximum illumination setting.