Raytracing, FSR and DLSS under the magnifying glass

The interesting mix of action, stealth and sandbox puzzles about the bald contract killer based on the Glacier engine has received a graphic update from developer IO Interactive. The chic, often very bright presentation and the technical progress constantly pushed by the developers through updates are part of the Hitman tradition, at least since the 2016 reboot. The first part of the newly started trilogy was one of the early titles with Direct-X-12 -Support, the second part shone in particular with its fine planar reflections, which almost gave the impression that the game was already using ray tracing. Now the already very respectable graphics with Hitman 3 have also taken this step and integrated chic real-time ray tracing.

The effects are limited to the shadows cast by the sun (or the moon) and reflections. As in the predecessor, these ensure the greatest visual ecstasy. So far, the assassin has not used global lighting based on real-time ray tracing, but the pre-calculated GI is one of the more impressive light shows. The reflections, however, provide a lot of flair and a much more organic presentation primarily on large, transparent glass surfaces – where they replace ugly pixelated cube maps – as well as on some water surfaces and reflective materials, while the ray-traced shadows leave a rather mixed impression.

Hitman 3 with ray tracing – light and shadow

The fine raytracing reflections help Hitman 3 (buy now )(as well as the levels of the predecessor, should you own the corresponding trilogy edition or the two access passes) to a significant graphic boost, which also makes the visual impression appear much more natural. Many, if not all, of the nearly ubiquitous reflective surfaces are now being ray traced, including larger bodies of water that are now much more detailed than before thanks to ray tracing. Many smaller details, including metal taps, shiny golden chandeliers or fine marble decorations, also receive chic ray tracing reflections. The very pretty transparency reflections, which refine shop windows, vehicle windows and other glass surfaces, bring a particularly impressive gain – and replace the often ugly and pixelated veil of the previously used cube map reflections.

Many of the former planar reflections that Hitman uses for mirrors, for example, are also replaced when the raytracing reflections are switched on. This improvement is one of the more inconspicuous innovations, because the planar reflections are already very convincing (with maximum details). With ray tracing, the resolution increases a little and the reflection is again a little more accurate, but this is often only noticeable on closer inspection. This is a good thing, because for some large, vertical, reflective surfaces – such as the huge windows of the skyscraper in the Dubai mission of the first part, planar reflections are still used in some cases, since ray tracing would obviously be too demanding for these large surfaces.

Other, large, reflective surfaces, such as wet asphalt or puddles, are only partially raytraced and show some imperfections. In puddles, for example, reflections of nearby objects are displayed with ray tracing, at greater distances screen space reflections fade in as a fallback – apart from the typical dropouts when covered, this is still relatively unobtrusive, but there is another fallback for the screen space reflections. reflections In the form of pixelated cube maps. This mixture of different reflection techniques, which is probably necessary for performance reasons, means that in the relevant reflections two distinctly different reflections are often visible at the same time.

The accurate ray tracing reflections, which are partly supported in the distance and relatively unobtrusively by screen space reflections, as well as a second, definitely inaccurate and often ugly pixelated cube map reflection, which due to the technical limitations of the technology often also has to do with the raytraced mirroring bites. Notice the two different reflections of the red gas station lights in this puddle. The sharp, clear reflection is the ray-traced reflection, the second perspective of this crossing, pixelated red outline in the puddle is the cube-map reflection. However, this problem also occurs without ray tracing, in fact the limited ray tracing display is the reason why this puddle, like many other shiny surfaces, shows these dropouts – since the reflections are not fully displayed with RT, this fallback is necessary. The RT representation in the puddles also has a sharp LoD, especially regarding vegetation.

Aside from the very chic transparency reflections, the occasionally convincing reflections on wet and glossy surfaces, there are a few other, smaller and larger, anomalies. However, these primarily affect the shadow display, which leaves a rather mixed impression. For one – you can already see this in the image comparisons above: If you disable raytracing shadows, the LoD or MIP level of the textures decreases. Notice the wall in the gas station example above, or the wall, balcony, and signs in the comparison below. The level of detail on the wall drops, the signs lose their visual coherence and the balcony now shows a flickering moiré pattern. This circumstance only occurs when disabling raytraced sun shadows, not when disabling RT reflections. Why this occurs is a mystery. Basically, nothing serious about the remaining level of detail should change as a result of ray tracing. And an increased MIP level is basically only necessary when using upsampling such as DLSS or FSR in order to preserve the level of detail despite the reduced original resolution.

However, that’s not the only mystery revealed when looking at the ray-traced shadows. The fact that these are only cast by the sun (or moon or more precisely: the skylight), i.e. all lamps, spotlights, candles and similar “artificial” light sources continue to cast shadow maps and, on top of that, a screen space surrounding occlusion is still used still technically understandable, after all the raytracing shadows are limited to this option. On top of that, many of the raytracing shadows are nicely filtered and, of course, typical shadow mapping weaknesses such as Peter panning, scaling or banding artifacts are eliminated.

Some shadows, such as those of the character and some objects in general, appear unnaturally sharp in some situations, and the visual gain is rather subtle. And that’s only until the ray-traced shadows show one of their many dropouts, including violent flickering, partial fading, missing on some objects, or general incompleteness. These errors occur with graphics cards from both manufacturers, so the problem obviously lies elsewhere. Here’s a negative example that we were confronted with almost constantly during testing – it’s our benchmark scene. The problems mentioned can also be observed in other environments, but here they are concentrated: the shadow of the dancers is incomplete or even depicts their skeleton. The shadows cast by the parasols are missing, only those of the spokes are drawn. When moving, many of these ray tracing shadows also flicker conspicuously and are extremely annoying.

DLSS 2.3.2 vs FSR 1.0

Hitman 3 supports both AMD’s open-platform upscaling algorithm FSR 1.0 and Nvidia’s proprietary AI upsampling DLSS (here in version 2.3.2). Both methods prove to be of great help with performance problems in our tests – but what about the quality? In order to evaluate these, we looked at various levels and would like to show you an example below that basically says it all. For optimal visibility, please click on “Full screen comparison”. The images were created in WQHD/1440p resolution, of course with lossless compression. We’re doing without zooms this time, because the effects of the performance modes in particular are striking.

Hitman 3 Upscaling Comparison: DLSS vs FSR

If you switch from native display to an upscaling process, the same things always happen, only the extent of them varies. If we first compare the best FSR 1.0 mode, Ultra Quality, with the native image, one thing becomes immediately clear: All types of aliasing increase due to the internally reduced resolution. What’s more, the unchangeable sharpening using rCAS (a modification of Contrast Adaptive Sharpening, CAS) further reinforces the crumbly impression. So it happens that not only subtleties such as the neon light kite and the cranes in the background are lost, but also that the noise (noise) from reflections becomes coarser. The reason for this is the reduced spatial resolution, which means fewer rays for ray tracing – this form of aliasing is difficult to compensate even for temporal supersampling.

The change to FSR 1.0 Quality amplifies all problems and also reduces, for example, the texture resolution by using a different MIP map on the delivery truck on the right in the picture. A comparison with DLSS Quality, which works with the same spatial resolution, reveals huge differences. The Nvidia process draws a completely different picture and proves to be effective anti-aliasing in the classic sense in comparison: pixel-fine details are not only preserved in comparison with the native display together with TAA, but are better reconstructed in an impressive way; All types of aliasing are decreasing. The latter includes the “filtering out” of high-frequency details, for example in puddles – DLSS Quality, just like FSR, reduces the amount of radiation, does without resharpening and therefore lacks sharpness of detail here.

Comparing FSR 1.0 performance and DLSS 2.3.2 performance in Hitman 3 reveals significant differences. Although both upscalers in the example work internally with 1,280 × 720 pixels, DLSS plays in a reconstruction league of its own. FSR swallows everything that makes Hitman 3 pretty and makes calls for FSR 2.0 ever louder – we hope to see it implemented soon, alongside Intel’s XeSS for the ultimate comparison. But even DLSS is far from perfect: Modes other than Quality tend to have severe aliasing/flickering within puddles – so severe that it looks like a bug. The annoying smearing, which is always found in the DLSS context, falls into a similar category: some objects, in Hitman 3 it’s mostly people, trail behind them a conspicuous tail, which is reminiscent of shooting stars. We’re excited to see when Nvidia gets this side effect of DLSS, which is found in almost every game, under control. Until then, however, DLSS Quality is a nice compromise.

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