What is Tesseract? Tesseract is a sort of Frankenstein's monster that escaped the lab when I ripped out the static lightmapped heart of Sauerbraten, squished it under-foot with extreme prejudice, and stitched it back together with deferred shading and shadowmapping.
Run-down of the cool new features:
HDR rendering with tonemapping and bloom
omnidirectional point-light shadowmaps
sunlight cascaded shadowmap
screen-space ambient occlusion
screen-space water reflections (no more reflection plane limits)
refractive alpha cubes
refractive glass material
A dorky video of some of this stuff in action:
The actual code is at a github repository for the moment:
See the README for some more details about running it.
The code is still under Zlib license.
The work on this code was done in collaboration with Benjamin Segovia over the last month or so.
The codebase is still in a state of high flux, so I would expect a lot of changes coming in the future.
The goal of all of this is not really to replace Sauerbraten and development on Sauerbraten itself will continue into the future. This is just a fork, a what-if experiment to see what it might look like if it dropped all concerns about compatibility and good performance on old hardware and just tried to modernize.
In fact, while it can load Sauerbraten maps, the lighting model of Tesseract is roughly incompatible, as not only do Sauerbraten maps use way too many lights, but Tesseract renders the lights a bit differently.
Tesseract is not at this moment endeavoring to be a stand-alone game, but just another parallel codebase people interested in the engine can choose from to work from if they want to mod it into a game of their own.