The Water Shader is specifically designed to provide a realistic water effect on Terragen surfaces, including wave-shaped displacement, reflectivity, and transparency. Specialized controls are provided to realistically simulate certain water phenomena, for example "wind patchiness".
- Roughness: Controls the general roughness of the water surface.
- Wave scale: The average wave size.
- Smallest scale: Determines the size of the smallest details. You may want to decrease this if the water shape looks too simplistic, or increase it if you're only viewing the water from a distance. The smaller this is, the more octaves there are in the Water Shader noise function and the longer render times will be.
- Wind patch effect: In nature, there are variations in wave structure and overall water smoothness across large bodies of water due to wind. This and the next two settings simulate this effect. The "Wind patch effect" setting controls the amount of variation there will be between different areas—effectively the strength of this effect.
- Wind patch size: Controls the average scale of the areas of variation.
- Wind patch sharpness: Sets how sharp the line between areas of variation will be. Put another way, this controls how smooth the transition between areas of different roughness is.
This tab controls the reflectivity of the water.
- Master reflectivity: Controls the overall level of reflectivity for the water.
- Index of refraction: The amount of light refraction caused by a given material, as indicated on index of refraction (or refractive index). 1.33 is the standard refractive index for water. Index of refraction also affects the reflectivity of a surface. The higher this number is, the more reflective the surface will be at angles facing towards the camera (e.g. when looking down at water below the camera).
- Horizon shift: This function is used to simulate the "shift" in reflection due to the aggregate effect of greater or lesser surface roughness on distant reflective surfaces. It will essentially shift the angle of distant reflection toward or away from the horizon.
- Highlight intensity: Controls the strength of specular highlights from light sources.
- Min highlight spread: Control how much "spread" the reflections have; in other words, how diffuse the specular highlights are.