Dreamcast Today

- SuperSolar - Dreamcast - Running at 60fps on real hardware!

It's finally time for the massive update I know EVERYONE has been eagerly waiting for... Presenting to you over 6 straight minutes of spliced footage directly captured from my actual physical Sega Dreamcast... RUNNING THE LATEST BUILD OF OUR SONIC MANIA PORT!!! I can't even begin to describe to you how polished and fantastic it's starting to feel... as though it belonged on the Dreamcast all-along... Thanks to the hard work of jnmartin, sonicfreak94, and a few others, not only is the Dreamcast port nearing completion, but... wait for it... THE 3D STAGES THAT STRUGGLED ON EVERY UNOFFICIAL PORT ARE NOW ALL RUNNING FULLSPEED!!!! Trust me when I say that this took an absolutely ENORMOUS amount of effort from jnmartin and the crew to pull off, considering the low-end for this game was the original Nintendo Switch, and ports running on consoles with twice our processing power struggled to run these levels fullspeed. The first and most obvious thing is that the 3D software renderer was ditched and all rendering was done natively with our PowerVR GPU... which actually wasn't as simple as it sounds. The tilemaps for these levels have had to be tessellated into a bajillion PVR quads and transformed and rendered as individual polygons to look correct and run faster than a slideshow. Mr anonymous Ocarina of Time chad developer came up with a pretty slick LoD scheme for drawing tiles closest to the player at 1x1 pixel sizes with sizes increasing with distance up to 2x2 and 4x4 pixels, allowing them to reduce the overall number of tile vertices that have to be transformed by the SH4 CPU and submitted to the PVR GPU, by strategically keeping the majority of the polygon detail closest to the camera, with detail decreasing as the tiles get further away. Next, the 3D geometry was preprocessed and converted from being triangle-based to being triangle-strip based, drastically reducing the number of vertices per model that our 200Mhz SH4 CPU had to transform (with plain integer arithmetic and no FPU vectorization, since this is all slow-ass fixed-point integer math)! Finally, it was discovered that the lighting was a disproportionately significant contributor to the TnL load on the SH4 for processing vertices. Jnmartin came to the realization that 99% of the time only the Y axis direction is considered for lighting equation intensity with just a white color. So this simplified lighting model got baked into the renderer, which gave another round of gainz. So in the end, after all of this work came together, a draw distance of 75% the distance of the retail Sonic Mania versions was achieved for the decorations, plus the character models have their full geometry count and have not been simplified on a freaking Sega Dreamcast with a 200Mhz SH4 CPU and only 16MB of RAM! 🔥