While there are many directions for video games to improve in the future. Animation being a big one. People are looking for things to do for graphics. First, avoiding the uncanny valley in next gen games may be a big problem. In general high level though (probably mostly obvious)
- Higher resolution textures.
- Higher resolution geometry.
- More world clutter and detail.
- Enormous worlds with little to no loading.
- I'd like to see water reflections that are actually reflections and not just cube-maps.
- Some people think that many more dynamic lights (1000's in a scene) are the future of video games.
- Soft shadows via variance shadow mapping or the like.
- Hair on video game characters will get a huge upgrade. No longer will characters look like they haven't showered for 2 weeks.
- Smoke using fluid simulations (this would be awesome)
- Geometry LOD is going to be a serious problem (even more so)
If you were to stick with triangles, then you would probably do some kind of subdivision surfaces.
There are other options though like voxels which can give triangles a serious run for their money. When properly optimized, they can provide very consistent frame rates irrespective of world detail.
Voxels aren't all static either. Lattice skinning can be used for characters, as well as I've seen some research in the area of dynamic KD-tree generation. There has also been some research in completely dynamic voxels, such that the world is actually changeable real-time. Leaving a foot-print in the sand actually leaves a foot-print there. Possibly permanently depending on how you implement it.
You could also do interesting procedural stuff if you had the compute power, where grass could grow back over craters over time, etc... Other benefits of voxels are the sampling you can do to do motion blur, depth of field, etc stochastically.
You can guarantee a framerate by doing progressive rendering of the frame. Stopping at a certain ms. That gives a lot of freedom to the content people to make the world how they see it in their imagination and no longer be limited by what hardware can provide.
All very interesting stuff, and I'm sure its only the tip of the iceberg.
However... things are not without its challenges. The PS4 may make the life of voxels a little harder. You will likely have to write a custom ray-casting solution for the PS4.
I'm sure many people will continue to use triangles. Hell, even I might. I'm a reasonable guy and will likely measure both approaches and pick the best one for the task at hand. However, ignoring voxels as an option seems kind of silly to me. The game developing public needs a good example implementation of voxels in order for it to really take hold in any sort of realistic way. There is an open source one from NVidia which has lots of ideas pulled from my stuff, however their solution is not really prime-time ready. For example, it doesn't stream from disk so you can only do what you can fit in memory. I don't really have time to write a public implementation of voxels, or to really contribute anything significant to the nvidia one. I'm just too darn busy right now. Who knows though, maybe I'll have time in the future.
Ok, enough voxel talk.
Another big challenge is going to be doing things for 3D displays. I don't have a lot of experience with 3D conversions for games yet, but I will very soon. I'll write more when I know more. Doing so in a deferred renderer seems like it might be a bit troublesome.
I'm sure there is much more that I could chat about here with next gen graphics. Taking each of the previous things in detail. Maybe I'll do a dedicated post to each one.