More and more we hear about ray tracing in games, and more and more new projects are getting support for this technology. The latest major tracing game was Remedy Entertainment’s action-adventure Control. And this game is an excellent demonstration of the new technology, so we will look at the nuances of tracing in this review. Let’s compare the image quality in normal mode and with tracing, simultaneously evaluating the changes in performance. We will also talk about NVIDIA DLSS technology and its impact on this game.
Control can run on DirectX 11 and DirectX 12. Ray tracing is only available on DirectX 12 and requires Windows 10 version 1809 or later. At the moment, the optimal solution for tracing games is the GeForce RTX series of graphics cards, although in theory you can enable new effects on GeForce GTX, but with very low performance. GeForce RTX has the best performance in ray tracing processing thanks to hardware acceleration and the presence of special RT blocks in GPU Turing.
In this game, ray tracing is used to build realistic reflections and reliable shading, taking into account direct and reflected light. In the graphics settings, there are five separate options for tracing and two preset quality profiles. High quality tracing offers all five options, with medium quality only two are enabled. The description of these settings is below:
- Reflected ray tracing. For realistic detail, consistency and off-screen reflections.
- Ray tracing of transparent reflections. For transparent objects such as glass.
- Ray tracing of indirect diffuse lighting. To improve the rendering of indirect lighting.
- Ray tracing of contact shadows. To improve the detail and accuracy of shadows.
- Debris tracing. Enables tracing for debris from destroyed objects.
The first two points can be considered the most important, since they provide the most obvious changes in graphics, adding reflections to most surrounding surfaces and improving reflections where they are and in normal mode. Indirect lighting tracing better takes into account the influence of reflected light, it will add color highlights from bright objects, affect the illumination of objects, taking into account reflected light. Contact shadow tracing will provide realistic shadow areas where objects touch. The last item activates all the complex tracing mechanisms for fragments that are formed after the destruction of objects. And since the game has a high destructibility of the environment, there are a lot of such fragments and this parameter can significantly affect performance in action scenes.
Let’s evaluate the visual changes on several examples. Initially, we ran the game at 4K resolution at maximum graphics settings with MSAA 2x anti-aliasing. For convenience, comparison screenshots are reduced to a resolution of 2560×1440, the comparison video is available in 4K.
In normal mode, glass has no reflections, but tracing immediately adds them. Moreover, in the reflection, the entire interior is visible behind the back of the heroine and another character located to her left. The area under the glass becomes lighter. And even on the costume of the heroine, glare appears, which makes its surface more textured.
There is a big difference between normal mode and simple tracing. But the improvement in the quality of RTX no longer affects the overall impression so clearly, although there are changes in the shadows and small nuances. Let’s try to understand these nuances on other examples.
Turn on tracing and get reflections on the glass. Also note that there are reflections on the metal parts of the red cylinders, and even the metal frame of the trolley changes its texture — instead of a plain material, there is a shiny surface with highlights from the light floor. Increasing the quality of the tracing affects the shadows, which is clearly visible from the flag and the far one on the right side of the frame. They are all out of direct light and are darker at high tracing than at medium.
For clarity, we will present some changes in the form of animated illustrations. First, a comparison of the reflections on the glass.
Now let’s look at the shadows at medium and high tracing quality.
There is a change in the shadow area under the cart and on items. Darker is the area behind the glass on the left side of the fragment.
There are really a lot of glasses in the game. But how does tracing affect other surfaces? Answer below.
Tracing changes reflections on the floor and highlights on the steps. Instead of blurry patches from pine trees, we get more detailed contours with green fragments. Glare appears on the railing at the edges of the frame. Medium tracing quality darkens the underside of the branches, high quality enhances this differentiation, helping to better emphasize the shape of the branches. Also, at high quality, the shadows from the railings on the sides are sharply reduced, which is more natural.
The following is another illustrative example. Let’s compare normal quality with the maximum tracing level.
The effect of dense light behind the heroine’s back is enhanced. There are new highlights on the sofa, boxes and other interior elements. Combining these highlights with changes in the shadows creates a distinct sense of directional light.
Below, these frames are presented in the form of an animated comparison.
The structure of reflections on the floor is changing — more details, brighter light spots from the lamps. This better emphasizes the texture of the surface and enhances the depth of the frame. Tracing changes the color and lightness of the shiny elements on the central column. There is a slight sheen from the lamps even on red surfaces.
Let’s compare a small fragment with medium and high tracing quality.
The main change at high quality is the red tint on the objects, which forms the light reflected from the floor. In the second mode, the shadows from the urn and under the chairs are darker, and the plants are lighter.
The following example will only show changes in object shading. The peculiarity of the scene is the presence of several lamps on the ceiling and many objects in the frame.
Tracing adds uneven illumination to many objects. Glare appears on the fan, boxes and some equipment, and the shadows at the points of contact become more intense. The large shadow on the left side of the frame is a little lighter, but there is also a «noise» effect, and this graininess looks unpleasant.
The appearance of a clearly defined light and dark side allows you to better highlight different objects.
NVIDIA DLSS Antialiasing
Now let’s look at the features of DLSS. DLSS (Deep Learning Super Sampling) technology uses deep learning to intelligently scale and smooth, replacing other anti-aliasing options and speeding up performance. Allows you to compensate for the drop in performance after turning on the tracing, but the detail of the picture may suffer.
Initially, DLSS anti-aliasing is focused on high-definition 4K. In Control, after activating this technology, you can adjust the input resolution. The best option is to select the maximum available input resolution of 2560×1440 for the resulting 4K DLSS (3840×2160). With these settings, we made a comparison. Below are full size images in native resolution 3840×2160.
Even with a detailed comparison, we noticed obvious changes only in the texture of the floor and the figure of the heroine — without DLSS they are a little clearer.
Next, a comparison of identical fragments.
Everything looks very positive for DLSS. The difference with the original 4K is hard to notice even with a detailed comparison. And the outlines of some objects with DLSS are smoother than in normal mode with MSAA 2x (pay attention to the back of the chair).
Let’s look at another comparison.
No noticeable changes! Even the fringe on the flag does not lose its shape.
Let’s supplement the given screenshots with comparison in video format.
The video is available in 4K. Recorded on NVIDIA GeForce RTX 2080 Ti.
Now let’s look at performance.
The test bench configuration is as follows:
- processor: Intel Core i7-6950X (firstname.lastname@example.org GHz);
- cooler: Noctua NH-D15 (two NF-A15 PWM fans, 140 mm, 1300 rpm);
- Video: NVIDIA GeForce RTX 2080 Ti Founders Edition;
- motherboard: MSI X99S MPower;
- memory: G.Skill F4-3200C14Q-32GTZ (4×8 GB, DDR4-3200, CL14-14-14-35);
- system disk: Kingston SSDNow KC400 (512 GB, SATA 6Gb/s);
- secondary drive: WD Red 3TB WD30EFRX (3 TB, SATA 6Gb/s, 5400 rpm);
- power supply: Raidmax Cobra RX-800AE;
- operating system: Windows 10 Pro x64;
- GeForce driver: NVIDIA GeForce 436.30.
The location «Research Center» was chosen for testing, as it had the lowest performance. A run from the elevator to the stairs was performed with a shootout and throwing objects at enemies. The tests were carried out at 2560×1440 and 3840×2160 resolutions.
The GeForce RTX 2080 Ti does well at 2560×1440, delivering over 60 fps with average tracing quality, but increasing settings further reduces performance to 50 fps and below. The performance drop from the entry level is 35% with medium quality RTX and up to 80% with high quality. Activating DLSS provides a 45-62% speedup.
In 4K resolution, the situation is more sad. Even with an average tracing quality, the average performance barely exceeds 30 fps, and with a high quality it is less than 24 fps. But DLSS provides an acceleration of about 80% in the most difficult mode. And with DLSS in 4K we get quite acceptable results.
Below is a 4K DLSS game demo with mid-range tracing effects.
Control is one of the best ray tracing demos in games right now. This technology adds detailed reflections where they weren’t there and improves where they were. Tracing changes the texture of some objects, adding reflective properties to them. Therefore, metal elements look more realistic. The overall shading changes. Depending on the illumination and the influence of reflected light, we see additional highlights and shadows on objects, which better emphasizes their volume and structure. There is a color effect of some surfaces on others. All this enhances the feeling of directional volumetric light and enhances the realism of the picture. And it fits perfectly into the overall style of the game with an abundance of shiny interiors and sophisticated lighting. New reflections and shadow nuances make the picture richer and more beautiful. After you play with tracing, you don’t want to return to simple mode at all.
The main problem of tracing is a strong drop in performance. The flagship GeForce RTX 2080 Ti video adapter allows you to play with tracing at a resolution of 2560×1440, but as the resolution increases further, the frame rate drops to an unacceptable level. NVIDIA DLSS technology comes to the rescue. If in some games this blurs the picture, then in Contrrol the image in 4K DLSS is minimally different from the original 4K. Therefore, feel free to turn on this mode for maximum resolution. And while someone is arguing about the appropriateness of tracing in games, happy owners of the GeForce RTX 2080 Ti can already play Control at 4K resolution with maximum graphics levels that are not available on older generation graphics cards.
As far as the difference between medium and high tracing quality is concerned, the first option is more practical — you get nice reflections and changes in shading at a more gentle performance drop. Further improvement of the tracing quality affects only shading and fragments, which is not so striking, but it hits the performance very hard.