Let me throw in an anecdote that may amuse some: I was working for a now defunct large game company when Epic and Tim Sweeny came in to demo Unreal Engine 3 very early before the PS3 and XBox360 were launched. This was about 2004. Their demo blew away executives in particular. They showed multicolored lights casting multicolored shadows on a single high detail character. One of the lights was behind a stained glass window, projecting beautiful patterns. Soon after a deal was signed to use the engine throughout the entire studio. In retrospect that was a good decision and I have a lot of respect for Unreal Engine and Epic in general.
However UE3-generation games that finally shipped had none of the visual effects from the early demos. The multicolored shadows could only be rendered with multiple passes, at least one per light, which proved to be too expensive for larger dynamic game scenes. It took years of work from the demo to shipped games, and an army of unnamed engineers to wrestle the technology into a product.
UE4 had a great early demo of dynamic global illumination using something like voxel cone tracing if I remember correctly. To my knowledge that tech demo was never incorporated into the engine and never shipped.
Epic is famous for their demos, and I love them for it... at least now that I no longer work professionally in that field. If anything it charts a long term technical direction for interactive entertainment.
Edit: found the video of the demo levels that shipped with very early UE3 https://www.youtube.com/watch?v=1m7T5ay_8DI
However UE3-generation games that finally shipped had none of the visual effects from the early demos. The multicolored shadows could only be rendered with multiple passes, at least one per light, which proved to be too expensive for larger dynamic game scenes. It took years of work from the demo to shipped games, and an army of unnamed engineers to wrestle the technology into a product.
UE4 had a great early demo of dynamic global illumination using something like voxel cone tracing if I remember correctly. To my knowledge that tech demo was never incorporated into the engine and never shipped.
Epic is famous for their demos, and I love them for it... at least now that I no longer work professionally in that field. If anything it charts a long term technical direction for interactive entertainment.