We see GTA 5 with graphics closer to photorealism through the technical changes made by Intel Labs with a series of tricks.
GTA 5 still represents an interesting workbench for graphics changes and new technologies to be applied to achieve a greater level of photorealism, as demonstrated by this reworking carried out by Intel Labs.
Researchers used Grand Theft Auto V to demonstrate technologies that can be used to enhance the photorealism effect from standard three-dimensional graphics. It is not really a mod to be distributed, but a real demonstration of the application of some graphic technologies aimed at “improving the realism of synthetic images”, as reported by the managers.
The end result is the result of a series of integrated enhancements that boost traditional rendering pipelines, apply a variety of post-processing effects and techniques, and change a wide range of elements that define the game’s graphic rendering.
The use of these technologies does not result in increased polygon size or texture quality in most cases, but it does result in a more realistic overall effect thanks to improvements made at various levels.
The amount and color of grass and foliage are increased, the visual distance is enhanced, reflections and shadows are changed, and the tone of light and colors is reshaped. The end result is less flashy and vibrant than the original GTA 5 graphics, but in several ways, it is similar to photorealism.
A detailed explanation of the same can be found here.