One of our aims with our global illumination implementation was to keep it as simple as possible, while still obtaining good performance, and we hoped to achieve that by using the GPU. While the are several approaches to compute global illumination in the GPU, the most simple one that we …
A little problem that we had when we started to create trees and vegetation is that the standard mipmap generation algorithms produced surprisingly bad results on alpha tested textures. As the trees moved farther away from the camera, the leafs faded out becoming almost transparent. Here’s an example. The following …
In The Witness we decided that it’s a good idea to have a heightfield terrain making up the bulk of the island surface. The advantages of this are in rendering performance and in ease of texturing (it is relatively easy, with one continuously-parameterized terrain block, to get rid of seams; …
In the previous part, I talked about my reasons for wanting to use Cascading Shadow Maps (one of the biggest: image stability), then said that we had implemented Michal Valient’s version of the algorithm, and mostly liked it, but wanted to reduce the memory usage. This time I’ll show how to …
As explained by Jon in his previous post, we are using precomputed global illumination in The Witness, and one of my first tasks was to work on that system. I have developed some interesting technology to compute automatic paramaterizations, to formulate the lighting computations in a way that can be …
It seems like time to post some images from the in-progress precoputed lighting tech that Ignacio is working on. See here for a description of the basics behind what we are doing for lighting. The lightmaps are now 16-bit and these shots use a simple exponential tone mapper. First, I’ve …
The Witness contains a mixture of indoor and outdoor scenes, but much of the game takes place outdoors with a very long view distance (you can see the entire island at once if you have a good vantage point). So I wanted to implement a shadow system that would work …
For the past 15 years or so, graphics technology in games has been driven by shooters. Most shooters generate visual interest in their scenes by having lots of dynamic lights, with extreme use of bump mapping, and moving shadows, and particle effects. For The Witness, I wanted to develop a …