Since i saw the Diablo 3 trees the first time on a screenshot, i noticed that there is something special. Their silhouettes were really detailed and i didn’t saw aliased edges during other objects HAD aliased ones.
I couldn’t believe it, when i saw how they did the trees. They painted them (alpha8) on slightly bent planes. That makes them only usable from one perspective, but therefore they look unbelievable detailed. And because of the fact, that camera rotation isn’t necessary in ARPGs, Blizzard shows that they’re masters in combining graphic and gameplay.
Robert asked in the comments about more details and to be honest i never was satisfied with the resolution of the GIF you can see above. Thanks to Roger and his great APP->OBJ converter (.APP is the filetype of Diablo3-models in the MPQ archives) i was able to create a version with better quality:
Robert mentioned, why it wouldn’t be possible to get the same result with “real” geometry and my answer would be: Of course it would be possible, but you would have to spend a lot more polygons to get the same great detailed silhouette. Here’s a single banch as example:
They used two triangles for this beautiful branch instead of x-thousand for a “real” model. And by the way: never forget that even the biggest mega-super-highpoly-model is just rendered to a flat surface (the frame buffer or let’s say: your monitor). So if we don’t talk about Occulus Rift (or other techniques which give a “real” 3D impression) and there’s no big change in the perspective (camera rotation, zooming, etc.) it might be enough to use 2D elements instead of going crazy with polygons. Just my personal opinion, correct me if I’m wrong. :)
By the way, if you’re interested here is the tree-texture (left: diffuse, right: alpha). It’s hard to look at them without getting jealous…they’re sooo beautiful! :,)
The question is, why not doing it more often like this? I think it’s because of the weight of this decision. Looking at computer graphics from an traditional art perspective isn’t easy all the time. Especially when you have people which only want awesome new tech features. “If we have a 3D engine, we have to be able to rotate the camera!”. If the person who screams like that is in a higher position than you are, your arguments that the camera rotation isn’t necessary (either for gameplay nor for art), can be overheard quickly.
Oh and i really recommend to watch the whole presentation. To see how Blizzard approaches to the field of computer graphic is just awesome and very helpful when all people around you are just shouting for the next DX99 features to place them on the game package – ignoring what the game really needs.