> Throwing more ( or finer etched) silicon at an algorithm will not help the algorithm, compared to a superior algorithm
Actually, it will when the complexity classes of the algorithms differ. Which is true in this case -- the time taken to ray trace a scene rises as the log(n) of the size of that scene, while the time taken to rasterize rises linearly with regards to the scene.
There exists a threshold of computing power/scene complexity above which raytracing beats rasterization in speed. However, like Carmack pointed out, the constant factors are massive, so this won't be reached in the near future, if ever.
The reason the constant factors are so huge is that complexity of raytracing rises linearly with the count of pixels to be drawn, while in rasterization a lot of the work can be shared by neighbouring pixels.
Intriguingly, this means that if you can reduce the pixel counts, you can vastly improve the value of raytracing.
Notably, if you can do eye tracking and rendering in less than 15ms, you can reach the same visual quality as a full-screen, high-resolution render by rendering only the areas you are actually looking at in high resolution, and rendering the rest of the scene at a progressively lower resolution farther from the focus point. The cone of high-precision vision is surprisingly small, something like tens of pixels when looking at a screen from a normal viewing distance. If you did this, you should be able to cut the amount of rays you need to send by at least two orders of magnitude, which would bring raytracing to real-time quality on modern hardware.
Actually, it will when the complexity classes of the algorithms differ. Which is true in this case -- the time taken to ray trace a scene rises as the log(n) of the size of that scene, while the time taken to rasterize rises linearly with regards to the scene.
There exists a threshold of computing power/scene complexity above which raytracing beats rasterization in speed. However, like Carmack pointed out, the constant factors are massive, so this won't be reached in the near future, if ever.
The reason the constant factors are so huge is that complexity of raytracing rises linearly with the count of pixels to be drawn, while in rasterization a lot of the work can be shared by neighbouring pixels.
Intriguingly, this means that if you can reduce the pixel counts, you can vastly improve the value of raytracing.
Notably, if you can do eye tracking and rendering in less than 15ms, you can reach the same visual quality as a full-screen, high-resolution render by rendering only the areas you are actually looking at in high resolution, and rendering the rest of the scene at a progressively lower resolution farther from the focus point. The cone of high-precision vision is surprisingly small, something like tens of pixels when looking at a screen from a normal viewing distance. If you did this, you should be able to cut the amount of rays you need to send by at least two orders of magnitude, which would bring raytracing to real-time quality on modern hardware.