Fix jagged lines and edges in FS2004 with the right resolution, anti-aliasing, driver profile and shimmer settings without blurring gauges.
To fix jagged lines and edges in Microsoft Flight Simulator 2004 (FS9), select your monitor’s native resolution with 32-bit colour, then enable the simulator’s anti-aliasing. If that remains weak, create a graphics-driver profile for fs9.exe and test a multisample override. Use anisotropic filtering separately for texture clarity and distant shimmer.
What causes jagged lines in FS2004?
Stair-stepped edges, shimmering textures and flickering scenery have different causes, so increasing anti-aliasing will not fix all of them.
| What you see | Likely cause | Best first adjustment |
|---|---|---|
| Steps along aircraft wings, buildings or 3D cockpit frames | Insufficient resolution or geometry anti-aliasing | Native resolution and multisample anti-aliasing |
| Runway markings or distant roofs that crawl as the view moves | Texture and mipmap aliasing | Mipmap tuning, trilinear or anisotropic filtering, and less sharpening |
| Jagged trees, fences or other cut-out textures | Alpha-tested transparency | Transparency anti-aliasing or supersampling, if available |
| Whole ground surfaces that flash between two images | Overlapping scenery or z-fighting | Correct the scenery layers |
| Rough or blurred artwork on one 2D panel | Low-resolution source artwork | Replace or repair the affected add-on |
| A horizontal split that appears only while panning | Screen tearing | Vertical synchronisation rather than anti-aliasing |
A mistake we see repeatedly is treating every moving line as an anti-aliasing fault. Freeze the view and inspect an aircraft edge against the sky: geometry aliasing remains as visible steps, while texture shimmer changes or disappears as the camera stops moving.
How do I smooth stair-step edges in FS2004?
Use native resolution first, FS2004’s own anti-aliasing second, and a per-program driver override only if the built-in result is inadequate.
- Select the native display mode. Open FS2004’s Display settings, choose the Hardware tab and select the resolution that matches the monitor, with 32-bit colour. A low-resolution full-screen image stretched across a modern panel makes diagonal lines visibly coarser.
- Enable anti-aliasing in FS2004. Tick the simulator’s anti-aliasing option, apply the change and restart FS2004 before judging it. Our step-by-step FS2004 anti-aliasing and driver-override instructions cover the setting in more detail.
- Check the correct details. Look at a wingtip, tailplane, building roof or 3D cockpit frame. Anti-aliasing should smooth these polygon edges; it will not repair a low-resolution panel bitmap.
- Create a profile for
fs9.exe. Close the simulator, open the graphics driver’s per-program settings and target the actual executable in the FS2004 installation folder. Avoid changing the global graphics profile, which can affect other games and simulators. - Test a modest multisample setting. Start with 2x or 4x MSAA rather than the most demanding option. If a true override produces no visible difference, the installed driver may no longer force that mode reliably for this legacy Direct3D application.
- Add anisotropic filtering separately. An 8x or 16x setting can sharpen runways and terrain viewed at a shallow angle, but it does not smooth the outline of an aircraft.
- Change one setting at a time. Compare the same aircraft, airport, view angle, weather and time of day. This prevents a sharper texture setting from being mistaken for better edge smoothing.
| Driver mode | FS2004 anti-aliasing box | When to use it |
|---|---|---|
| Application-controlled | Enabled | Best starting point and least likely to cause conflicts |
| Enhance application setting | Enabled | Use only if the driver offers it and the result visibly improves |
| Override application setting | Disabled | Use when FS2004’s own anti-aliasing is weak and the driver can force MSAA |
Do not choose an enhancement mode and then disable anti-aliasing inside FS2004; an enhancement normally needs the application’s own AA request to be active. If you have altered many options already, return to a known-good FS2004 graphics baseline before testing further.
Why do runway and taxiway lines still shimmer?
Runway markings can continue to shimmer after aircraft edges are smooth because they are texture detail, not polygon silhouettes.
- Lower MIP mapping quality one step: Very sharp distant mip levels can sparkle as the viewpoint moves. Avoid dropping the setting straight to its minimum, which can make terrain and runways unnecessarily muddy.
- Use suitable texture filtering: Trilinear filtering softens transitions between mip levels, while anisotropic filtering preserves detail on surfaces viewed at an angle.
- Remove excessive sharpening: Negative texture LOD bias and aggressive driver sharpening can bring distant crawling back even when filtering is enabled.
- Try transparency anti-aliasing: If the driver offers it, this may help fences, trees and other cut-out textures. It generally has little effect on ordinary painted runway markings.
- Inspect the affected add-on: Shimmer confined to one aircraft or airport often indicates textures without suitable mipmaps rather than a global FS2004 setting.
For persistent crawling on terrain, roofs and runway textures, use our focused FS2004 texture-shimmer troubleshooting steps rather than continually increasing geometry anti-aliasing.
Should I use MSAA, supersampling or FXAA?
MSAA is normally the best first choice for FS2004 because it smooths hard geometry edges without applying a blur filter to the entire image.
- Multisample anti-aliasing: Choose this for aircraft outlines, buildings and 3D cockpit structures. Start at 2x or 4x and increase it only if the improvement is visible.
- Transparency anti-aliasing: Add this when vegetation, railings or fences remain rough. Multisample transparency modes usually cost less performance than supersample modes.
- Supersampling or downsampling: Consider these when thin transparent details and texture shimmer remain and the graphics card has spare capacity. They can reduce performance sharply at high rendering resolutions.
- FXAA or another whole-image filter: Treat it as a fallback. It can soften small 2D gauge labels, menu text and fine cockpit markings along with the unwanted edges.
Avoid stacking FS2004 anti-aliasing, a driver override, supersampling and whole-image smoothing at the same time. The result is often softer rather than cleaner, and it becomes difficult to identify which setting is responsible.
What if anti-aliasing has no effect?
If anti-aliasing changes nothing, the profile is usually targeting the wrong executable, the selected override is unsupported, or the visible fault is not geometry aliasing.
- Confirm the executable: The driver profile must point to
fs9.exe, not a desktop shortcut, configuration utility or add-on launcher. - Check which GPU runs FS2004: On systems with integrated and dedicated graphics, edit the profile for the processor actually rendering the simulator.
- Reset conflicting additions: Temporarily disable graphics wrappers, post-processing injectors, global sharpening and global anti-aliasing overrides before testing the standard renderer.
- Compare full-screen and windowed modes: Some legacy driver overrides behave differently between them. If only one mode responds, use application-controlled AA in the other.
- Test a default aircraft and airport: If the problem affects only one add-on, its geometry, transparency or texture mipmaps are the likely cause.
- Rebuild the configuration only as a last step: Close FS2004, back up and rename
%APPDATA%\Microsoft\FS9\FS9.cfg, then launch the simulator to create a fresh file. This resets many preferences, so reselect the resolution and graphics options afterwards.
An FS9.cfg tweak cannot add an anti-aliasing mode that the simulator or driver does not support. Rebuilding the file helps only when display settings are corrupted, fail to save or refer to graphics hardware that is no longer installed.
How can I tell if the problem is scenery flicker instead?
Scenery flicker affects overlapping surfaces or objects, whereas aliasing produces stable stair steps or fine crawling detail.
If a runway, apron or building surface alternates between two textures as the viewpoint changes, increasing MSAA will not solve it. Check for duplicate airports, overlapping scenery layers and conflicting ground polygons using our scenery-layer and z-fighting checks for FS2004.