Rayve started as an experiment to see if ray tracing could replace rasterization for typical games. Ray tracing has a lot of great advantages. But even with RTX cores, ray tracing was found to be too slow for rendering full scenes at good frame rates.
Raylogic worked for years on a new technique to make ray tracing fast enough for games. A lot of odd ideas ended up working great. RTX cores ended up being used in ways they were not intended. OpenGL, DirectX and Vulkan* graphics API's were elliminated. A new modified form of ray tracing was worked out.
The result was a big leap in ray tracing frame rates, making fully ray traced games possible. Nvidia's DLSS, antialiasing and scaling are not needed.
The downside is dependency on ray accelerator cores. The hope is higher ray accelerator counts will someday be common everywhere, even on mobile and consoles. For now, Rayve requires Nvidia and Windows, which fortunately is a big demographic for PC's. Rayve can run decently on lower end Nvidia cards. AMD support planned.
*A bit of Vulkan is used to access the GPU and display, but the Vulkan graphics API is not used.
Rasterization is the most widely used method for rendering games. It originated in the days of VGA cards to take advantage of the hardware blitting of 2D images. Assembly code was used on the CPU to cull and transform triangles in 3D space, then project (flatten) triangles to 2D so the hardware blitter could render triangles to the display fast. Lighting and shadows had to be done after 2D projection, which was complicated. GPU pipelines are still based on the rasterization model.
Because lighting and shadows are challenging with rasterization, many game engines use shaders to integrate ray tracing for lighting. If an engine handles all lighting with ray tracing shaders, it's called 'full ray tracing'. But the core rendering pipeline remains rasterization based.
Rayve abandons rasterization entirely. Ray tracing in Rayve is the full rendering architecture. All graphics are rendered through a small Raylogic developed ray tracing core. There is no vertex/pixel processing or 2D projection. Rays are bounced directly off scene objects where they sit onto the display. PBR materials, lighting, shadows and reflections happen as a natural part of the ray tracing process. Even user interface elements are ray traced.