Hey there, let’s dive into why your map fits perfectly in the Unity Editor but leaves vertical blank space on mobile—this is a super common gotcha with Unity’s UI scaling, so I’ll walk you through the most likely fixes based on my experience:

1. Safe Area is Restricting Your Map #

Modern phones have notches, rounded corners, or punch-hole cameras, and Unity’s Safe Area component automatically shrinks UI content to avoid these areas. If your map is attached to a Canvas with a Safe Area component, that’s probably why you’re seeing vertical gaps.

• Fix: Either remove the Safe Area component from your Canvas, or adjust your map’s Rect Transform anchors to stretch beyond the safe area (set anchors to (0,0) and (1,1) so it fills the entire screen).

2. Aspect Ratio Mismatch with Your Reference Resolution #

Your reference resolution is 1080×1920 (16:9), but many modern phones use taller aspect ratios like 19.5:9 or 20:9. When using Scale With Screen Size, Unity preserves the reference aspect ratio, so taller screens will leave vertical blank space if your match settings aren’t tuned right.

• Fix: Go to your Canvas’s UI Scale Mode settings, and adjust the Match slider. If you want the map to fill the vertical space first, set Match to 1 (Height). This will scale the UI to fit the screen’s height, and let the width adjust accordingly instead of leaving vertical gaps.

3. Incorrect Rect Transform Anchors/Pivot for the Map #

If your map is a UI element (like an Image), its Rect Transform settings might be preventing it from stretching to the screen edges.

• Fix: Select your map object, open the Rect Transform inspector, and set the anchors to stretch from (0,0) (bottom-left) to (1,1) (top-right). Make sure the Left, Right, Top, and Bottom values are all 0 so there’s no padding. Double-check the pivot is set to (0.5, 0.5) (or whatever makes sense for your map) to avoid alignment issues.

4. Camera Settings (If Your Map is in World Space) #

If your map is a 3D/2D world object (not a UI element), your camera’s orthographic size or aspect ratio might not be adapting to the mobile screen.

• Fix: For an orthographic camera, calculate the correct orthographic size dynamically at runtime with code:

  void Start()
  {
      float pixelsPerUnit = 100; // Replace with your map's texture pixels per unit
      Camera.main.orthographicSize = Screen.height / 2 / pixelsPerUnit;
  }
  

  Also, ensure the camera’s aspect ratio is set to auto-adjust (Unity usually handles this by default, but it’s worth checking in the Camera inspector).

5. Player Settings Hiding System Bars #

If your mobile device’s status bar or navigation bar is visible, it takes up screen space that your map isn’t accounting for.

• Fix: In Unity’s Player Settings > Resolution and Presentation, check the boxes for Hide Status Bar and Hide Navigation Bar. This forces the game to run in fullscreen mode, so your map can use the entire screen real estate.

Start with the first two fixes—Safe Area and Canvas Match settings—since those are the most common causes of this exact issue. Test on your target device after each change to see which one resolves the vertical blank space.

内容的提问来源于stack exchange，提问作者Cagri