Tilt Proof
Tilt shift in games
Bryce Kerr Abraham | Kathleen Ruiz | 27 April 2021
Tilt Proof is a graphical demo of the tilt-shift technique used in photography employed within a video game. In this demo, the player controls a camera that looks down on a peaceful fall cottage. The tilt shift effect is applied to the camera creating the famous miniature realism that tilt shift is known for.
Technical Setup
The demo is created in Unity 2020.2.4 with the HDR pipeline. The scene consists of a landscape populated with shrubs, grass, and trees with the house as a focal centerpiece.
The camera system is devised of two main parts. The controls and the post-processing filters. The camera controls are set up like an RTS game where the camera pivot is at the center of the world with the camera parented at an offset. This allows for rotational pivot movement and elevated translational movement along the x and z axis with a variable zoom controlling the y offset.
The tilt shift filter is implemented using Unity's shader graph. Unlike some post-processing effects, instead of using Unity's rendering buffer, I chose a more practical approach taking inspiration from actual cameras and giving Unity’s virtual cameras a “lens”. A lens is a plane in front of the camera with applied shader graph material.
The tilt shift shader graph applies a blur effect on the “lens plane” by multiplying each pixel over each other adjacent pixels. We feed the screen and color into a tile node 6 different times for an amplification effect. Our blur variable then multiplies these offsets by varying amounts blurring the pixels.
Applying this to the emission output now would burr the entire plane. Instead, we then create a mask via the sphere node along with gradient nodes to control the intensity toward the center. Applying this mask gives us our tilt shift effect where we can see through the plane in the center but the sides are blurred.
Game Practicality
The tilt-shift effect is very much a distortion of reality. Few games take this distortion and implement it digitally. Its benefits in a game could help focus one's attention, provide realism and greater depth of field, and improve look aesthetic. The negative effects within a game could comprise of a dropped frame rate, distracted player, impeded field of few, and incorrect implementation depending on the scenario.
Moving Forward
My implementation of the effect would be in a setting such as this demo. The camera height, its distance, and its focus all provide a great setup for some sort of relaxing RTS game. Building this out further would mean planning out mechanics based on this depth of field and blur style. Combined with calming world building this effect has great potential.
