It is through the surface settings that the user can start to tweak how the actual world itself is represented in the final image. The surface settings encompasses everything to do with rendering world geometry, such as blocks, entities, the player, particles, etc. The shader exposes settings for both terrain and water Parallax, Shadows, Ambient Light, Specular, Global Illumination, and general Materials.
Parallax is an effect that can be used to simulate 3D depth within an otherwise ordinary, 2D texture. Parallax achieves this simply by ray marching within a height map to find points on the height map that occlude, or block other points. We march towards the eye for the general parallax effect, and towards the sun/moon for parallax shadows. On the terrain, for both general parallax and parallax shadows, the height map is supplied by a resource pack, where on water, the height map is generated procedurally, using the same code as the waves.
Continuum exposes several settings for the user to play with.
Parallax depth influences the unit scale within the height map, which causes parallax to either be shallower or deeper, depending on the depth. Not only is this useful for personalizing Continuum, but it is also useful for tailoring Continuum to different resource packs. While Continuum is designed to work with Pulchra, it uses a different standard for height units, which means parallax has to be tailored specifically for Pulchra. By increasing the parallax depth, however, other resource packs can be used with Continuum's parallax.
Parallax Quality (Water)
Parallax quality is used to determine the amount of steps taken by the ray march, which can improve quality and accuracy. Parallax quality is only available for water parallax, as terrain parallax dynamically determines the amount of steps required for the ray march, leading to pixel perfect parallax, with no over or under sampling.
Parallax Shadows (Terrain)
Parallax shadows are a new effect to Continuum, which allow for geometry within the height map to cast shadows onto other geometry within the height map. This effect has greatly improved the impression of 3D depth that parallax provides, and serves to further ground everything within the scene. Like ordinary parallax, parallax shadows dynamically determine the amount of steps required for the ray march, leading to pixel perfect shadows, with no over or under sampling. This is especially important for parallax shadows, as without the adequate amount of steps, some shadows may not be picked up by the ray march.