[QUOTE=AndreGB;1239019]Right, Menzel. But I was thinking: wouldn’t it be possible for developers to come up with great stuff using OpenGL 3 or earlier? If we roll back not such a long time ago, id Software did something amazing (at the time) with Doom 3. I remember how cool it was watching all those Doom 3 pre-release in-game videos and how hard it was to believe they were actual in-game. What was that? OpenGL 2.x?
Not that I am saying the features on OpenGL 4 are useless (much on the contary, see my other topic). But developers have always found creative solutions for technological “contraints” (such as MacOS OpenGL support). Personally, I really love the tesselation features, but I could do without them given those incredible lightning effects on Unreal Engine 4 (check also the Samaritan demo). Are those effects really exclusive to OpenGL 4?[/QUOTE]
As I said, some state-of-the-art techniques require more recent hardware features than 3.2. When Carmack developed Doom 3 he used then state-of-the-art OpenGL, not an older version. It was in fact 1.4 with some extensions to get roughly to the feature level of 2.0 (which was available when Doom3 came out but not during development).
Regarding the Samaritan demo: The morphing of the guys face is done on the tessellation shader. The reflections are image-based and could in fact be implemented in simpler shaders. Have you seen the newer Elemental demo? The lighting there looks like cone-traced indirect lighting (look up Cyril Crassins paper "Interactive Indirect Illumination Using Voxel Cone Tracing). You need atomic operations and image read/write for the octree building there.
Sure, you can make games in GL 3.2, you can also make some in GL 1.4 - if you like to be stuck with Doom-like graphics. If you want to make graphics as realistic as possible, you will need the latest techniques. And GL 4 capable hardware is getting quite common (esp. on Macs).