Rail Planet Performance Settings: RENDER_DIST, Glow, and Transparency Explained

Rail Planet renders large city maps with hundreds of buildings, so frame rate depends heavily on three settings: render distance, object glow, and rail transparency. This guide explains what each one costs, the platform limits, and how to tune them for your device.

The three settings that matter

RENDER_DIST (render distance)

Controls how far away terrain and buildings stay visible. Higher values look better but cost more frames, especially in dense city maps where every extra chunk means more buildings.

Platform caps:

Start low (8–12) on a mid-range device and raise the value until the frame rate dips, then back off one step.

Object glow

Glow highlights landmarks and important objects. It is visually cheap in open areas but adds cost in cities with many glowing structures. New York behaves specially:

• During the day, glow defaults to OFF.
• At night, glow switches ON automatically.
• If you toggle it manually, your choice stays in effect.

If you need frames during daytime city play, leave glow off.

Rail transparency

Transparent rails are pretty but force alpha blending over large areas of the screen. In scenes where rails cross many buildings, lowering rail transparency is one of the cheapest ways to recover FPS.

Engine Workload Analysis Across 3 Map Profiles

The table below illustrates the relative rendering workload and chunk allocation across different world types in the production WebGL engine. These ratios reflect how geometric complexity scales with view distance:

Key takeaway: In dense city maps like Manhattan, reducing RENDER_DIST from 30 to 16 significantly cuts active chunk geometries, providing an immediate reduction in frame time volatility.

Memory Recovery: Chunk Pruning & Geometry Flush

As you travel across extensive voxel terrain on rails or in high-speed flight, the engine dynamically instantiates new chunk meshes. To prevent out-of-memory crashes on mobile browsers with limited VRAM:

1. Distance-Based Chunk Pruning: Chunks exceeding RENDER_DIST + 4 radius are unmounted and transferred to an object reuse pool, avoiding repeated garbage collection pauses.
2. Destruction Voxel Flush: When large structures collapse or small nukes carve craters, debris particles are culled after 4 seconds and the underlying chunk geometry is rebuilt in a single batched buffer update.

Recommended starting profiles

Low-end mobile:   RENDER_DIST 6–8,   glow OFF, rail transparency LOW
Mid-range mobile: RENDER_DIST 10–14, glow AUTO, rail transparency MEDIUM
Desktop / PC:     RENDER_DIST 16–24, glow AUTO, rail transparency HIGH
High-end PC:      RENDER_DIST up to 30, everything high

How to tune in practice

1. Load the map you play most (Manhattan is the heaviest common case).
2. Fly to a dense area — between buildings, not above the park.
3. Watch the frame rate, then lower one setting at a time: render distance first, transparency second, glow third.
4. Stop as soon as movement feels smooth; do not chase maximum visual quality in dense zones.

Dense city scenes are the right benchmark. If the game runs smoothly between skyscrapers, it will run smoothly everywhere else.

A note on the Manhattan mobile rule

On mobile devices the Manhattan map forces RENDER_DIST=5 automatically. This is not a bug — Manhattan packs far more buildings than the other maps, and the forced value keeps the map playable. Other maps on the same device keep your normal slider range.

Frequently asked questions

Q. What is the maximum render distance on PC?

1. The settings slider is capped at 30 on PC, while mobile tops out at 20.

Q. Why does my mobile device show RENDER_DIST 5 in Manhattan?

The Manhattan map forces render distance to 5 on mobile for performance. Your setting applies normally on every other map.

Q. Does object glow hurt FPS?

Mostly in dense city scenes with many glowing landmarks, and at night when it switches on automatically in New York. Turning it off is a real FPS saving there.

Q. Which single setting gives the biggest FPS gain?

Render distance. It controls how much of the city the game keeps active at once, so lowering it helps more than any visual toggle.