@hariseldon please add the homepage to your OP:
http://brechpunkt.de/q2vkpt/ and the Github:
https://github.com/cschied/q2vkpt/
My biggest issue with ray tracing is that a lot of it looks similar to effects already in use right now. I know they're faked, but they're faked quite well with a much lower gpu cost. The beginning of that first video for example looks like they added screen space reflections to Quake 2, instead of ray tracing. I know ray tracing is more accurate, but the final results still looks fairly similar.
Pathtracing is more about subtle details that you should not notice.
For instance, i was initially surprised that the grunt's laser beams weren't reflecting, but i realized later they are indeed doing that, but much more subdued. Because i am so used to the original release having a light casted when it shoots a beam, you are met back when you aren't seeing that effect as exaggerated as it really is.
The realistic approach here is a much more subdued light, which makes sense.
Even so, their custom made denoising filter still is not perfect as this shot shows: (Actually i can't show it right now since the site seems to be under heavy traffic, yay)
If existing RTX stuff is anything to go by it's probably a hybrid technique that combines rasterized base geometry with raytraced lighting, shadows and reflections. If it was pure raytracing then it'd probably be as noisy as q2pt / Raylgun.
Its a full path tracer.
Does Q2VKPT use the original light maps?
The original Quake 2 engine uses precomputed light maps that contain soft shadows and diffuse indirect illumination. In contrast, Q2VKPT entirely replaces the static illumination using a fully dynamic simulation that unifies both the static and dynamic light sources.
How many rays does Q2VKPT cast per pixel?
The number of rays that are cast are dependent on the first visible surface. For opaque surfaces Q2VKPT uses one ray each to find the direct and indirectly visible surface. Additionally, for both surfaces Q2VKPT casts one ray each towards randomly chosen light sources. Therefore Q2VKPT will cast at least 4 rays for each pixel.
Does Q2VKPT rely on rasterization?
Traditionally, games use the rasterizer to find the surfaces visible from the camera. Q2VKPT is fully raytraced and does not rely on the rasterizer (except for the 2D user interface elements).
Same here, save for the accurate water reflections and a subtle effect with the those skirting board floor lights. They should have done a side-by-side comparison.
On the homepage:
http://brechpunkt.de/q2vkpt/#media
I feel like this could be faked
Still cool demo tho
You can only reach approximations and achieve a
similar look but you will miss the details, which is what this project is all about.