Pragmata Ray Tracing Path Tracing Artifacts | Ghosting Boiling & Noise | DLSS Ray Reconstruction

Added: 2026-05-04

[00:00:00]Pragmata uses relatively low-resolution ray trace reflections so much so that there is heavy temporal reuse to stabilize them. So, when you're moving from one scene to another or if the screen is snapping from one surface to another, you'll see a lot of blurring.

[00:00:16]Like in this case, the wet road here gets heavy blurring when the door closes and opens.

[00:00:37]Something similar happens when something on screen is blocking the reflective surfaces. You get this heavy noise and artifacting because all the reflective data on screen reflective data isn't really able to temporarily reuse it from the previous frames as the previous frame the surfaces are being blocked by these barricades.

[00:00:57]And this pretty much wrecks the ray trace reflections.

[00:01:03]When there's limited light or the surfaces reflecting are relatively dark, this also has a terrible impact on the reflections as seen here.

[00:01:11]The temporal reuse isn't quite working as intended here because the light is less and there aren't enough samples to render decent reflections even with temporal reuse.

[00:01:35]When the reflecting source is too far from the camera or the player character, most of the reflective detail is lost when they're moved or removed from the screen.

[00:01:46]But even when they're on the screen, the reflections are often blurry, noisy, and tend to artifact a lot.

[00:01:57]The ray trace reflection related artifacts occur even in regular scenes.

[00:02:01]Even if you're not moving that fast, the area around the player character's body tends to artifact a lot producing this noisiness.

[00:02:10]This is once again due to the denoiser failing to properly reuse and reject the previous frame. This particular artifact is fortunately fixed by path tracing and ray reconstruction.

[00:02:50]Similar boiling artifacts are also seen with the color bleeding and global illumination with ray tracing.

[00:03:02]Fortunately, once again, path tracing fixes it well.

[00:03:11]Reflections when in motion, particularly uh it's unstable with ray tracing as seen here. This goes for both static as well as the player character's reflections. You can see that they're noisy as well as kind of ghosting around here and there.

[00:03:27]Furthermore, you can see that the player character's reflection seems to lack color. It's just essentially a shadow.

[00:03:37]Here's another example where ray tracing causes ghosting. In this case, you can see that the light here, the light samples from this light here are transferred over to future frames and aren't rejected quickly enough when you're moving the camera fast. As a result, you see that the light isn't reactive and takes a while to be completely eliminated from the frames when you move the camera around. This case, you can see that the ray tracing isn't casting a player character's reflection in the mirror behind.

[00:04:05]Furthermore, there's a lot of noise associated with specular global illumination, which is global illumination on semi-specular, semi-glossy surfaces. This once again is likely on fault of the denoiser, which isn't able to clean up these uh global illumination with the relatively low amount of samples, good samples available. Path tracing, even though it uses the more complex ray reconstruction denoiser, comes with its own share of faults. For example, the reflection rays are often too short and tend to miss out on the reflections that are just off the screen. Here, for example, you can see that the lights on the pillar are covered, but the pillar itself, which is due to the reflection ray being too short, is omitted as soon as you move just farther away from the railing.

[00:04:53]There's a substantial loss in color detail for path traced reflections even when the light casting them are on screen. Here, for example, when you see when the player character is near that light bulb, Diana's hair is blond and yellow in the reflection. But as soon as you move away from that light, the color is lost.

[00:05:20]Here once again, the color retention with the reflections in path tracing is a little off. Diana's hair, instead of being light brown blond, turns whitish with a strange glow even when you're close to this particular light source. I believe the game is treating her hair as a reflective or semi-glossy object.

[00:05:40]In this example, you can clearly see that the building up top is lit with a white colored diffuse bounce lighting as well as direct lighting. But in the reflection here, it often disappears. This happens when you move away from the building or if the camera is tilted farther away from it. Now, I know I'm probably nitpicking here, but it's worth noting that path tracing is extremely expensive in this game and you'd expect at least a building that's a few uh dozen meters away from you to be reflected properly with its colors and lighting.

[00:06:13]In this example, even though path tracing substantially improves the quality of bounce lighting including the colored light bleeding effect, the DLSS ray reconstruction denoiser completely annihilates the detail, the terrain detail, the detail on the road here.

[00:06:36]As mentioned earlier, the player character's reflection here seems static even though he's moving from time to time. This is once again a fault of being cached or temporal overuse and not on time rejection of samples.

[00:06:51]Here's another example where even though there's ample diffuse light in the scene, the reflection lacks any color detail and that doesn't change even if you move around in the scene and move closer to these light sources. The reflection of the player character is completely colorless.

[00:07:10]Here's an example where path tracing and ray reconstruction also produces those boiling artifacts. Here you can see that when you're at an intermediate distance from a light source, particularly with the camera close to the light source, the boiling intensifies. But as you move it away, it gradually reduces and it eventually disappears if you move it farther away from the light source.

[00:07:37]This hints at there being a limit from the player character or the screen at which there is the distance to which rays travel. When you move it farther away from the light source, the rays don't account for that light at all. But when you include it in the screen, there are light samples, but not enough to cast a decent uh bounce lighting or bounced shadows effect.