New Terrain Shader Research

[Isaac]

Hi Everyone!

Recently we have been researching new techniques for rendering terrains, specifically on the shader development side. Much of this research is inspired by some of the GDC talks about landscape rendering over the past couple of years. 

One of the areas of interests was in reducing the amount of splatmaps needed for terrains. Currently, Unity supports multiple terrain layers through splatmap textures, where each channel (Red, Green, Blue and Alpha) represents a terrain layer mask (white for telling the shader to paint it at that pixel, black for telling it to not paint it). In our early research we have been able to find a method that reduces the number of splatmaps down to 1 per terrain. There are some visual tradeoffs to be made with this approach, but does allow some benefits such as supporting more than the traditional 8 terrain layers that Unity supports. 

Working along side this system is also the idea of having each pixel on the terrain know all the information about where it is spacially, what terrain slice it is, and it's terrain layers. This idea would potentially also reduce the amount of draw calls required for the rendering of the terrain, as many terrain tiles could use the same material.

We won't go into the specifics here, as it is still in early development, but we do have ideas for other features that could work with this terrain approach, such as integrating the weather system that is in development, adding tessellation and displacement, reducing the visible tiling of textures and object blending into the terrain. 

For now, here a basic showcase of the customly developed terrain shader, without using any of Unity's terrain tools:

Let us know your ideas for a new terrain shader you would like to see!