| Peh said: Ok, I understand where you are coming from and please don't do that. You are interchanging terms and methods. |
No I'm not.
When I talk about Ray Casting, Path Tracing, Photon Mapping... I am talking about Ray Tracing.
There is not an interchanging of terms there... If I use "Ray Tracing" instead of one of the above, then I mean Ray Tracing in a broad and generic term... Because that is what it is.
| Peh said: Yes, Raytracing is an umbrella term, but it is also a method -> algorithm. Raycasting is a method which falls under the umbrella term, but it is NOT Raytracing (Raytracing algorithm). |
I don't think I need to point out the conflict here.
So "Ray Casting" falls under the Ray Tracing "Umbrella" term, but it's not Ray Tracing? Righteo then. No sense to be made out of that logic.
| Peh said: That's like saying that Half Life 1 is using the Quake engine. This is simply incorrect. If you say that Doom or in my example Wolfenstein 3D is using Raytracing, because it uses a method which just belongs under the umbrella term, then you end up confusing everyone. When I refer to Raytracing, I'm always speaking of the algorithm. |
You are delving into the false equivalency logical fallacy.
A game engine is not a rendering methodology.
A game engine is a "collection" of technologies/modules/systems all coming together in a complete and cohesive (for the most part) package which is the necessary foundation to operate a game. - Some engines will leverage "middleware" such as Havok or Speed Tree to do things like Physics or Tree Rendering.
Half Life 1 is using GoldSrc which is... Like you stated, based on the Quake and Quake 2 engines which is entirely iD Tech.
But it's also been heavily rebuilt/enhanced in various ways... I.E. Valve completely stripped out the A.I and rebuilt the A.I system completely from scratch.
It's essentially a "Fork" of iDTech that goes in a different direction entirely... And this actually happens all the time in the software industry.
But that cannot happen with Ray Tracing. They are set Algorithms, not something that gets "thrown away" and rebuilt from the ground up, mathematics and physics is the basis of Ray Tracing and there are only a finite amount of ways to realistically approach that problem which tends to be dictated by the levels of performance the hardware offers.
| Peh said: And here also: "And Again... Conker used a Hemisphere lighting model which shoots a single ray of light. A single Ray. That is still Ray Tracing." No, please be more specific which algorithm is used. Using one ray, does not equal to it being the raytracing algorithm. Let's follow your logic like that: Global Illumination is an umbrella term for several algorithms including Ambient occlusion. That would mean that games that are using Ambient Occlusion are using a method of Global Illumination which is correct, but could be also labeled (by you) as using Raytracing (Because you consider GI is Raytracing) which is wrong. Do you see where I am going with this? |
It is literally shooting a "Ray of Light". - It's the very definition of Ray Tracing.
How many Rays of light, under your very narrow definition does it eventually become Ray Tracing?
5? 10? 100? 1,000?
As for Ambient Occlusion... You need to understand how that works.
Ambient Occlusion works by having "rays" that are cast from each geometric surface.
When those rays come into contact with another surface, they will become darker. - If not, they retain their degree of brightness.
And by it's very definition means it is also Ray Tracing.
But there are multiple ways of doing Ambient Occlusion... Which results in it not being Ray Tracing.
Some developers will "bake" the detailing into the texture maps (I.E. No hardware overhead).
Fun fact... With the inclusion of Ray Tracing cores in modern GPU's, we now hardware accelerate Ambient Occlusion on the Ray Tracing cores (Which thus gets renamed to RTAO), I don't need to explain why though. (Because maybe it's a Ray Tracing operation perhaps?)
During the 7th gen console generation, developers would pre-calculate Global Illumination light bounces into various maps and layered them on top of assets as it requires a significant degree of computational capacity.
But during the 8th gen with dynamic lighting and global illumination being the key buzz word and the hardware now caught up to low-end PC's, light bounces with full dynamic lighting are being used, which is Ray Tracing.
| Peh said: Beam Tracing and Cone Tracing are derivatives of the raytracing algorithm. It says so in the very first beginning of your links. Thus they cannot be a Raytracing algorithm. They are their own algorithms called Beam Tracing and Cone Tracing. Path tracing is the closest that comes to the Raytracing algorithm, but still does something else. Otherwise it would be called Raytracing algorithm 2.0. And that's the point. |
It's all Ray Tracing. Shifting the goal post doesn't really change that.
Path Tracing isn't even the best form of Ray Tracing. There is no "Closest" that comes to Ray Tracing. It either is Ray Tracing or it isn't.
There is no set-requirement for what Ray Tracing functionally is other than it uses light bounces and it interacts with surfaces... And that could be light bounces to simulate shadows rather than lighting.
| Peh said: If I read that someone added Raytracing to a game (Quake3), by unifying 20 AMD-XP1800-CPU's, than I doubt he used something different than the actual Raytracing algorithm. |
What is the "actual" Ray Tracing algorithm in your strange definition? How many light bounces? Does it use Voxels or Cones? Does it use Beams? Does it use Screen-space data to sample geometry surfaces? Does it use de-noising? Does it interact with surfaces?
Quake 3 however used a direct lighting model, it didn't propagate light. And it was achieved with light maps or vertex. (I.E. 3dfx Voodoo.)
By leveraging 20x AMD Palomino/Thoroughbred chips, they would have been able to do a very slow software Ray Traced render.
Just because it's Ray Tracing, doesn't mean it's going to be photo-realistic and pixel-perfect, so doing it on a CPU-farm like that individual would have been a far higher quality implementation than something that is using a single light bounce entirely on the GPU back then.
| Peh said: When the industry speaks about Raytracing, they will refer by 99% to the raytracing algorithm and not a derivative or any other method under the umbrella term. And so do I. |
What Ray Tracing algorithm? Many games use Path Tracing which is Ray Tracing.
But many future games will use Voxel Cone Tracing. (I.E. Unreal Engine 5 games.) Which is also Ray Tracing.
So which is the industry actually talking about? Unless... If your prior comment is anything to gauge by, Path Tracing is the "Closest" thing we have to Ray Tracing, so it must be superior to Voxel Cone Tracing, which in turn makes the Unreal Engine 5 demonstration absolute horse shit from a technical perspective then, meaning it's lighting graphics is crap?
| Peh said: When I ask "Since when did consoles rendered scenes with Raytracing in realtime?" I am referring to the raytracing algorithm. Hope I could clear this up. |
Conker. It used a single ray of light in real time. I provided the evidence for that prior.
And it was a stunning looking game in it's day.
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