Control Review: Ray Tracing Features Put You In Control
Ray-Traced Translucent Reflections
Most reflections in traditionally-rendered games can only reflect what's on the screen, since many performance optimization techniques discard pixels that aren't visible in the current scene. On the other hand, Control's reflections take the whole room into account. Control uses NVIDIA's RTX technology to trace light rays from the area around you to cast reflections. When Jesse looks through a window, for example, objects outside the camera view behind her are visible in her reflection.
Without ray tracing, you can see through the glass into the next room and the glass reflects some light. It looks good, but it's not anything we haven't seen before. The paneling farther down the hall reflects some light, but the next room looks insanely bright and there's very little of that reflected on the wall. The graphics of this scene are nice, but let's turn on ray tracing.
First of all, the reflections in the glass are gorgeous, especially in motion. You can see the cart in the window, but also the wall across the hallway. The ray tracing effects on display here give the scene a whole lot of extra realism.
In this area, all the architecture consists of glossy, glassy cubes. Without ray tracing, the lighting appears to come from directly above Jesse. The scenery just reflects a lot of light, and it looks good, but it just feels like something is missing.
With ray tracing enabled, nearby architecture appears in reflections. This adds to the immersion, and we found ourselves just standing in a room or area and looking around. Fortunately, the early sections of Control present enough breaks between enemies that you can treat it as a sort of playground.
Ray-Traced Indirect Diffuse Lighting"Ray-traced indirect diffuse lighting" is a lot of opaque words to describe light rays traced between surfaces that aren't perfectly glossy or reflective. Light bouncing off a matte surface is diffused, or scattered, in a way that doesn't create a bright glare. The result is that you can see the light in the room. For nearby surfaces, the game traces one bounce of diffuse reflection. When there isn't an available surface nearby, the game falls back to the typical pre-computed global illumination map, as if there was no ray tracing support.
This very official-looking office building has wood paneling and marble floor decor with a long red carpet that seemingly leads you from room to room. With no ray tracing, there's definitely some haze in the air and an indistinct glare coming off the wall at the end of the hallway. The lighting looks kind of flat and we don't really feel a lot of depth.
With ray tracing, that haze now it feels like it's hanging in the air. It's applied a little too thickly for our tastes, since it makes us think more of the fog on a mountain top than an otherwise-sterile office building. Fortunately it's not so heavy-handed even just a couple of minutes farther into the game.
Ray-Traced Contact ShadowsEveryone is familiar with the detail deficit in shadow mapping. Sometimes it appears as a coarse aliasing effect around the shadow, such as high-detail shadows in Grand Theft Auto V, or as a "freckling" shadows in GTA IV, where the shadows are created as a series of dots. Control uses RTX to avoid that kind of obvious flaw in its shadows by tracing shadows in real-time in areas where shadows are close to the caster. As the shadow gets farther away from whatever caused it, the game blends traditional soft shadows using shadow maps.
With no ray tracing effects applied, the sunlight beaming into this office looks nice enough, and Jesse's shadow looks good. It's hard to tell in this screenshot, but her shadow overlaps a nearby desk's shadow. Let's see if turning on ray tracing makes it more obvious.
There's a lot going on here, and most of Control's ray tracing effects appear in subtle ways. The legs of Jesse's shadow are lighter, since there is a lamp on the desk just out of frame. Higher up, the shadow darkens because the desk obfuscates the lamp's light and Jesse's shadow merges with the desk's, which is cast by an entirely different light source. Not only are the shadows impressive, but at the same time you can see reflections in the glossy floor. The cabinet and shelving unit are mostly out of view, but they make their presence known by their reflections through ray tracing.
Control: DLSS Anti-AliasingWith the GeForce RTX series, NVIDIA promoted a new anti-aliasing technique: Deep Learning Super Sampling. DLSS improves performance by rendering the game at a lower resolution and then upscaling it, complete with anti-aliasing, to your display's native resolution. Control renders the game at one of two resolutions (720p or 960p) and then DLSS upscales the image to your display's native resolution. Let's take a peek at the difference between no anti-aliasing at 1440p, 4x multi-sampled anti-aliasing, and DLSS upscaling from 960p. When we get to the performance section, you can decide if it's worth the trade off.
First up is our baseline image, which we took at 2560x1440 with both the ray tracing and traditional graphics settings High preset, but with 4x Multi-Sampled Anti-Aliasing (4x MSAA is standard on the Medium and High graphical presets) disabled. The result looks nice and all, but thanks to the high contrast levels of our test scene, aliasing is apparent throughout. In Jesse's hair, one little strand sticks out of the top of her noggin, and it's aliased to the point that it's no longer connected to her scalp.
When we turn the MSAA back on, many of the aliasing artifacts disappear entirely. That little loopy strand of hair is thin, but well-defined. Also, the stairstep effect on the railing and in the ceiling is significantly lessened. This is what we expect from MSAA, and NVIDIA's implementation of the algorithm looks really nice in Control.
960p DLSS doesn't look quite as nice as 1440p MSAA. When you're standing still, it's not up to the standard set by 1440p MSAA. DLSS isn't magic—because the source image still has less detail at 960p than it does at 1440p; there's only so much post-processing can do. However, when the game is in motion and not zoomed way in like it is above, we're very hard-pressed to tell a difference. When we get to the performance section, we'll talk turkey about what kind of performance gains you can expect.