Archive for the ‘rendering’ Category
We’ve recently started searching for ways to optimize our terrain renderer. Our current implementation uses material splatting with user specified weights per material, as well as decals for extra details (e.g. roads, foot steps, etc.). For distant terrain we use a base layer, in order to minimize the amount of work required to render the terrain. Here I’ll talk about our attempt on virtual textures, the difficulties we’ve encountered and how we are planning on integrating the technique into the engine.
One method for reducing the aliasing of traditional shadow maps, is to soften the edges. By using such a technique the alliasing problem of the depth shadow maps is less noticeable and the resulting image is closer to the real world shadows. Also textures with lower resolution can be used without noticeable visual artifacts.
Update 2012-06-24: Links to the original page/paper seems to be dead. Search for Parallel-Split Shadow Maps for Large-scale Virtual Environments on google and you’ll find it.
Parallel Split Shadow Maps (PSSM) is a shadow mapping technique which tries to minimize shadow aliasing by splitting the view frustum into smaller regions, each one covered by a separate small shadow buffer, effectively distributing the shadow buffer resolution more evenly along the view frustum. For more details on how the algorithm works see the original paper.
What we will present here is the way we integrated PSSM into the engine. First we’ll take a look at how different shadow algorithms can be implemented as plugins to the engine, based on one common interface, and then we will jump into the details of our implementation.