How do I fix jagged lines and edges in FS2004?

To fix jagged lines and edges in FS2004, run the simulator at your monitor’s native resolution, enable anti-aliasing, and, if FS2004’s own option is too weak, override it in the graphics driver for fs9.exe. Use anisotropic filtering for blurry ground textures; it does not replace anti-aliasing.

What causes jagged lines in FS2004?

In Microsoft Flight Simulator 2004 (FS9), different visual artefacts require different settings, even when they are all described as jagged edges or shimmer.

Our explanation of how anti-aliasing works in older flight simulators covers the distinction between geometry, texture and transparency aliasing in more detail.

How do I remove stair-step edges?

Use this order: native resolution first, FS2004 anti-aliasing second, then a per-program graphics-driver override if required.

1. Select the monitor’s native resolution. Open FS2004’s Display settings, choose the Hardware tab and select a resolution matching the display, with 32-bit colour. Stretching a low-resolution full-screen image makes every diagonal edge more obvious.
2. Enable FS2004 anti-aliasing. Tick the simulator’s anti-aliasing option, exit FS2004 fully and relaunch it. If aircraft wings and building outlines become smooth, leave the graphics driver set to application-controlled.
3. Create a profile for FS2004. If the built-in option is inadequate, add fs9.exe to the graphics driver’s per-program settings. Do not change the global profile, as that can affect every other simulator and application.
4. Try a multisample override. Where the driver offers an Override application setting mode, start with 4x multisampling. Clear FS2004’s own anti-aliasing box when using a true override. If the override has no visible effect, return the driver to application-controlled mode and re-enable anti-aliasing inside FS2004; some modern drivers do not reliably force every legacy Direct3D mode.
5. Add anisotropic filtering separately. An 8x or 16x setting improves runway and ground-texture clarity at shallow viewing angles, but it will not smooth an aircraft’s silhouette.
6. Compare one change at a time. Use the same aircraft, airport, view angle and time of day. Check a wing edge against the sky and runway markings in the distance before increasing another setting.

If several display options have already been changed, our balanced FS2004 graphics and frame-rate baseline provides a cleaner starting point.

Why do runway and taxiway lines still shimmer?

Runway and taxiway markings can shimmer after aircraft edges are smooth because they are often texture detail rather than polygon silhouette edges.

• Adjust mipmap quality: Lower FS2004’s MIP mapping quality by one step if distant markings crawl or sparkle. Do not immediately move it to the minimum, which can make runways and terrain unnecessarily muddy.
• Keep anisotropic filtering enabled: It preserves texture detail viewed at an angle. Avoid forcing a negative texture LOD bias or aggressive driver sharpening, both of which can bring shimmer back.
• Try transparency multisampling: This can improve fences and vegetation. It may not affect painted runway markings.
• Recognise z-fighting: If entire ground layers flash or alternate rather than merely looking jagged, anti-aliasing is not the answer. Follow our steps for diagnosing FS2004 ground-scenery flicker and check for overlapping add-on scenery.

Should I use multisampling, supersampling or FXAA?

Multisampling is normally the best first choice for FS2004 because it smooths geometry without noticeably softening gauges and panel text.

• MSAA: Use for aircraft, buildings and other hard polygon edges.
• Transparency anti-aliasing: Add it when trees, fences or other cut-out textures remain jagged. Multisample transparency modes cost less performance than supersample modes.
• Supersampling or downsampling: Use only when texture shimmer remains and the computer has ample graphics headroom. These methods process more samples and can reduce performance sharply at high resolutions.
• FXAA: Treat it as a fallback. Its whole-image smoothing can blur FS2004’s small 2D gauge labels and menu text.

Do not stack every available method at once. Combining in-game anti-aliasing, a driver override, supersampling and post-process smoothing makes faults harder to identify and can produce a softer image rather than a cleaner one.

What if anti-aliasing has no effect?

If anti-aliasing changes nothing, the driver profile is probably attached to the wrong executable, the override is unsupported, or FS2004 is retaining a stale display configuration.

• Check the executable: The driver profile must target fs9.exe, not a desktop shortcut or add-on launcher.
• Check dual-GPU systems: Make sure FS2004 is using the same graphics processor whose profile you edited.
• Remove conflicting enhancements: Temporarily return added graphics wrappers, injectors and global driver sharpening to their defaults.
• Test one default aircraft and airport: If only a particular add-on remains jagged, the add-on’s model or textures are the likely cause.
• Rebuild the configuration: Back up and rename %APPDATA%\Microsoft\FS9\FS9.cfg, then start FS2004 so it creates a fresh file. This resets simulator preferences, so reselect the display resolution and other custom settings afterwards.

Will an FS9.cfg tweak fix jagged edges?

An FS9.cfg edit does not create anti-aliasing that the simulator or graphics driver cannot provide. Rebuilding the file is useful only when display settings fail to save, appear corrupted or no longer match the active graphics hardware.