Motion Smoothing

Celeste Motion Smoothing

A mod for Celeste that greatly improves the smoothness of the camera and Madeline, and also can raise the FPS above 60 without breaking physics. You do not need a high refresh rate monitor to get the vast majority of the benefit of Motion Smoothing! The higher fps options work by keeping the physics update at a fixed 60 FPS but rendering using extrapolated entity/camera/etc positions during at 120+ FPS. Motion Smoothing should work with most modded maps, but please read the Smooth Camera section for more on compatibility.

I have verified the accuracy of physics with this mod enabled by running the Any% TAS, which still finishes like normal, but at a buttery smooth 120+ FPS!

Rendering Mode

Motion Smoothing makes changes to Celeste's rendering pipeline to add its features. This setting affects how large those changes are, which has several effects.

• Fancy: [Recommended] Substantially changes the rendering pipeline to render everything at a 6x internal scale. This allows for high quality camera smoothing, smooth parallax in the background and foreground, and rendering Madeline with subpixel precision (see the following settings). This mode is the most performance-intensive, and it is incompatible with a very small number of other mods. If you encounter any visual glitches, please ping Cruz (the current maintainer) in the Celeste discord server.

• Fast: Unlocks the camera from the pixel grid, but otherwise doesn't change the rendering code. This allows for camera smoothing, but not the other features mentioned above. It also makes the background jitter while moving when camera smoothing is turned on. This mode is a degraded experience, but it should have negligible impact on performance and fewer visual glitches.

• Off: This turns Motion Smoothing off completely.

Smooth Camera

This lets the camera move continuously: that is, half of a pixel could be shown on the side of the screen while the camera is moving. This is especially noticeable when the camera is slowly catching up to the player. This works regardless of FPS, so if you only have a 60hz monitor, this option will still make the game much smoother! Like everything in this mod, this does not affect physics at all.

Render Madeline with Subpixel Precision

In Fancy mode, Madeline can be drawn at her exact, subpixel-precise position while moving, which dramatically improves the clarity of her sprite. There are many safeguards in place to prevent subpixel information from being gleanable. Turning this setting off may mildly improve performance.

Smooth Background

In Fancy mode, the background can be drawn unlocked from the pixel grid, which makes parallax backgrounds substantially smoother. Turning this setting off may mildly *reduce *performance, especially in levels with unusually complicated backgrounds.

Smooth Foreground

This is identical to the smooth background setting, but for foreground objects (for example, the snow in chapter 7 drifts smoothly when this is on, rather than being snapped to the pixel grid). Turning this setting off may mildly *reduce *performance, especially in levels with unusually complicated foregrounds.

Higher Framerates

Motion Smoothing always keeps Celeste's physics running at 60 FPS. When the framerate is increased above 60, the extra frames in between physics frames are rendered by predicting where all of the objects in the level (including Madeline) should be, based on their current positions and velocities.

Object Smoothing

There are two slightly different ways to predict where objects will be on non-physics frames.

• Extrapolate: [Recommended] Uses objects' current velocities to predict where they should be. When objects unexpectedly change velocity, this can introduce very brief visual artifacts. In practice, this is so rare and so brief that it is functionally unnoticeable.

• Interpolate: Uses the last two physics frames to calculate exactly where objects should be in between. This is more technically correct, but it adds an extra 1–2 frames of input delay.

• Off: Object smoothing can also be disabled completely. This means objects will always be drawn at their exact physics position at 60 FPS, regardless of the game's framerate. Very high level players that can react to frame-perfect lineups may be interested in this setting.

Framerate Increase Method

Raising the framerate above 60 can be accomplished in two ways:

• Interval: [Recommended] Draws one or more extra frames per physics frame. This has the best compatibility, but it restricts the FPS to increments of 60. For a 144hz monitor, you could try 120 or 180 and see which looks the

best.

• Dynamic: Decouples the physics updates from the rendering. This allows any framerate (like 144, or even below 60 for fun) but at the cost of mod compatibility: while it's unusual, any mod that tries to hook the main XNA Tick method, like TAS recorder, will not work

properly.

Stabilize Madeline's Hair

Madeline's hair is normally rendered in a way that can make its edges flicker when they should stay still, like holding left or right when falling. This fixes that flicker and makes her hair render smoothly.

For Map Makers

Motion Smoothing allows you to use high-res stylegrounds in your maps, and you can add triggers to change certain settings. See the GitHub page for details on both.