How Rain Works in Starfield And In Most Other Games

How Rain Works in Starfield

Starfield players had a fascinating revelation this week regarding their in-game characters and the weather systems within the game. It turns out that their characters are seemingly accompanied by personalized rain clouds that follow them around planets, much like the famous scene in “The Truman Show.” Unlike typical games where rain falls uniformly across a given area, in Starfield, rain appears exclusively where the player’s character roams. This phenomenon was shared by a Starfield player on Reddit, who posted a screenshot from the game’s photo mode, displaying a distinct block of rain encircling their character while the rest of the environment remained dry.

Although this discovery was surprising to players, it’s not exclusive to Starfield. Game developers reveal that this technique is a common practice in the gaming industry. Thomas Francis, the lead visual effects artist at Red Hook, known for developing Darkest Dungeon, shed light on the practice. He explained that attaching rain visual effects to the game’s camera is a performance optimization strategy. This method avoids rendering every raindrop in the game but focuses on what is directly in front of the camera.

However, what makes the Starfield situation unique is that the grid or block of rain appears to be connected to the character rather than the camera. Some players were unable to replicate this effect, as the rain seemed to deactivate when they entered the game’s photo mode.

Karl Schecht, a 3D environment artist, emphasized that many games employ such “clever trickery” as a standard practice. Even when everything on the screen looks real, there’s often a significant difference beneath the surface. Schecht explained that everything in a video game, including lighting, reflections, weather effects, and scenery, is part of a carefully crafted system designed to look and feel realistic while running smoothly on gaming consoles or PCs.

In Starfield, rain only exists in a small area around the player.
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He used the rain in Starfield as an example, noting that it appears solid whether the player is in first-person or third-person mode. However, when you switch to photo mode and zoom out, you can observe that the rain is actually a small particle system, typically about 3×3 meters in size, hovering above your character.

David Szymanski, the creator of Iron Lung, provided more insight into the effect. Rain in games is usually generated with a particle system, which efficiently renders numerous similar raindrops in motion. However, rendering hundreds of thousands of raindrops on the screen, especially if they have transparency, can be demanding on processing power. To optimize this, developers can reduce the size and number of raindrops, linking them to either the player or the camera to create the appearance of a substantial downpour from the player’s perspective while keeping resource usage in check.

In the world of video game development, optimization is crucial. It prevents unnecessary overhead, which can strain the CPU and GPU. Reducing this overhead helps ensure smooth gameplay. The “cost” mentioned here isn’t financial but refers to resource usage. Developers must manage resources efficiently, like in a resource management game, to maintain a balanced and enjoyable gaming experience.

These techniques, while common knowledge among developers, are so effective that players typically don’t notice them in games like Starfield. This insight offers a rare glimpse into the behind-the-scenes work of game development and the creative tricks used to make games both visually stunning and performant. As Thomas Francis put it, it’s like showing players the “wizard behind the curtain” and seeing their reactions to the secrets of game development.