With teaching on the MSc done with for a while, I’ve had a bit of spare time to work on my engine. As well as the projective lights from the previous post, I’ve finally got round to implementing a basic materials system, allowing me to have differing specularity and brightness values for each texture colour used. To implement this, I first had to generate a ‘materials’ layer for my texture atlas system, to go with the diffuse and normals layers I already had. To generate the actual materials texture, I adapted my Syndicate Wars texture loader, and palette-shifted all of the game’s textures and sprites to a predefined material lookup index – so for example, all water pixels get a new palette index of 56. This proved to be trickier than anticipated, as in some textures ‘green’ is the colour of polluted water, while in another it might be a dull metal, or grass, so I had to cut up the source textures into sub sections when loading them in, and then palette-shift each individually.

Anyway, from this material lookup index, I extract the per-material properties from a couple of 1D textures, allowing me to finally get rid of that annoying ‘shiny’ grass! Seems like a lot of work for not much, but as a nice side effect of changing how I cut up textures, the ‘stretched’ textures of adverts and police signs are stretched no more! Also, it means I can generate mipmaps with less inter-texture bleeding – hooray!