What technology does Starcraft 2 use render its maps?

Question

I've got a map that is being procedurally generated at run-time and I'm currently investigating methods of rendering this map. I've taken an interest in the look of Starcraft 2 and I'd like some advise on what methods it employs to achieve it. Secondarily, I'd like to see any tutorials, articles, or even source code examples if possible.

There are a couple of main things I'd like to get some advise on, but please also feel free to suggest anything else that could help me.

1. Snappable Tilesets - A typical starcraft map seems to consist of a tileset of models that one can snap together to create the cliffs, ramps and other elevated terrain. What methods do they employ to make them look so natural? What I mean is, its very hard to spot repetition.

2. Terrain Textures - The terrain textures are so varied and even dynamic (Zerg creep). What methods are used to do this?

Thanks.

Answer 1

I think part of it may just be that Blizzard has an amazing number of texture artists. But let's rephrase the question a bit:

I have a limited budget and want to make a realtime strategy game without obviously tiling textures. How can I accomplish that?

Good question! Here's a few big tools that I'd use:

1) A reasonably large set of interchangeable tiles. Say you're going with a 64x64 texture size on your grid: make eight 64x64 textures, any of which can tile with any others, and you've got a nice-looking tilebased game with a lot of variation!

2) Decals or megatexturing. Take your repeated texture and a small number of "smudge" or "dirt" or "scuff" overlay textures. Splatter a few of those overlays on your textures. These can be rendered in realtime, in which case they're decals, or baked into a ginormous texture, in which case it's called megatexturing. In either case you can probably do it semi-randomly, and you'll get a lot of variation with only a few applied overlays.

3) Cicada tiles. Check out this for more detail on how this works. In summary, it's a way to take a small number of partially-transparent obviously-tiling backgrounds and use it to generate a far-less-obviously-tiling background.

4) Texture splatting. I've saved this one for last because it's not really about avoiding tiling on a single texture, it's really about combining multiple textures seamlessly. However, if you can manage to eke out a few extra textures in your budget, this can be a critical tool - in fact, I'd say if you're not using this, you're probably doing something wrong. This won't help with large obviously-tiled sections of a single texture type, but this is what you'll use to make your various textures look good next to each other.