The Witcher 3: Wild Hunt transplant team Sabre Interactive recently mentioned in an email with the media GamesBeat about the difficulty of porting the game.
At the beginning they reportedly tried to reduce the number of NPCs by 30%, removed dynamic shadows and ambient light, but this made the game look very bad, so they went back and looked for other optimization possibilities, such as animation, AI, rendering , Cloth. When the initial version was completed, the game could only run at 10 frames, the memory footprint was half that of the Switch, and the size was 20GB larger than the largest cassette.
In order to optimize the game to an acceptable level, they made a lot of optimizations in vegetation, shadows, lighting and other basic algorithms to ensure that they look close to the original appearance. Finally, they worked tirelessly for a year to finally make the game reach 30 frames. And some degree of visual effects are retained.