A link to the excellent publications would be excellent.Some readers may ask what path tracing is and how it is different from ray tracing; for this, there are some excellent publications. In short, ray patching is a subset of ray tracing methods, albeit with considerably lower requirements for computing resources.
It's possible they may look off given that artists will have to work around the limitations of the rendering system they're using. Like for instance, Gensis games when going over a digital output look worse in some cases because artists relied on composite artifacting and dithering to produce transparency effects or nice color gradients.Am I missing something or do all the new screenshots look way worse?
Maybe it is just my monitor / settings but when I look at images 3 & 4 it seems that the original has better textures and the new one looks a bit washed out. I haven't played the original so maybe I'm not fit to comment but aside from the nice lighting through the windows in image 5 and overall better shadows (excluding the torch lighting as @hotaru.hino said) I didn't see much improvement in the new shots (in my personal opinion).
Torch light maps are obviously broken.AMD's senior graphics R&D engineer preps path tracer for Return to Castle Wolfenstein.
AMD Engineer Brings Path Tracing To Return to Castle Wolfenstein : Read more
There are many many effects to ray tracing. The current focus are ambients (subtle light tinting due to surface reflections of light). Reflections (like in rain puddles or windows, or mirrored balls) is still incredibly computationally expensive as if it's a perfect surface (mirror), rough point approximation won't cut it here. This is where cubic maps come into play and it's a similar technique similar to how the latest unreal engine creates interiors for offices in a huge city for the Matrix demo. There are other RT techniques like caustics that can be simulated with shaders. For example water surface reflections that grow more opaque at certain critical angles. Focal depth blurring based on Z Buffer and Gaussian blurs. And volumetric "fog" based on z-buffer comparisons.It is not an oversimplified explanation, it is a flat out wrong explanation.
Ray tracing is a fundamental technique to determine visibility of primitives. By itself, it does not generate images.
One can apply ray tracing techniques to create images or parts of them: for example, rendering reflections with ray tracing is an application of it. So is rendering AO using ray tracing. Or path tracing, it is a method for simulation indirect light using ray tracing. It is neither a sub nor a superset of ray tracing.