Microsoft Flight Sim: Fixing Photogrammetry Lag via Config

The primary bottleneck for Photogrammetry is not just your internet speed, but the Data Threading within the engine. When the “MainThread” is overwhelmed, the engine prioritizes flight physics over texture streaming, leading to blurry cities. Modifying the configuration file allows us to force a higher TerrainLoDFactor, which tells the simulator to request high-resolution assets much further in advance, effectively pre-loading the city before you arrive.

Hardware Compatibility & Expectations

• Storage Speed: An NVMe SSD is mandatory for these tweaks. A “Rolling Cache” on a slow HDD will actually cause more stuttering.
• VRAM Requirements: Increasing LOD factors pushes more geometry into the VRAM. 10GB+ is recommended for a Terrain LOD of 4.0 or higher.
• Network Stability: While we can optimize the engine, a stable 50Mbps+ connection is required to feed the Photogrammetry data.

Backup and Preparation

The UserCfg.opt file contains your core rendering flags. Errors here can cause the “Blue Bar” loading screen to hang indefinitely.

1. Completely exit Microsoft Flight Simulator.
2. Navigate to your local AppData or Steam folder (path below).
3. Copy UserCfg.opt, right-click, and save a backup copy on your desktop.
4. Open the original file with Notepad++.

File Location

The location varies based on your version (Microsoft Store vs. Steam):

MS Store: %LocalAppData%\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\UserCfg.opt Steam: %AppData%\Microsoft Flight Simulator\UserCfg.opt

Best Config Settings for Photogrammetry

Search for the Graphics and Terrain sections. Update these specific values to stabilize asset streaming:

{Terrain
	LoDFactor 4.000000
}
{ObjectsLoD
	LoDFactor 2.000000
}
{PostProcess
	Sharpen 1.000000
	Fringe 0.000000
	FilmGrain 0.000000
}

Pro Tip: Changing LoDFactor to 4.000000 (equivalent to 400 in-game) is the “sweet spot” for high-end PCs. It significantly reduces the “melted building” look by loading the 3D geometry from a much greater distance.

Key Parameters Explained

Parameter	Recommended Value	Impact
Terrain LoDFactor	4.000000	Forces the engine to load 3D buildings from 4x the standard distance.
Objects LoD	2.000000	Keeps airport ground equipment and static planes detailed at a distance.
Fringe	0.000000	Disables Chromatic Aberration, which often makes photogrammetry look “blurry” at the edges.
Sharpen	1.000000	Adds a necessary layer of clarity to the satellite-derived textures.

In-Game Settings vs. Config

To complement your config tweaks, match these in-game Data and Graphics settings:

• Rolling Cache: Set to ON with a size of at least 32GB on an SSD. This saves previously visited cities, preventing the engine from re-downloading them.
• Off-Screen Terrain Pre-Caching: Set to Ultra. This reduces stuttering when you pan the camera quickly.
• Photogrammetry: Set to ON (obviously), but ensure Bing Data World Graphics is also enabled.
• Texture Synthesis: Set to Ultra. This helps the engine “fill in the gaps” when photogrammetry data is slightly corrupted.

Troubleshooting & Common Fixes

• Infinite Loading Screen: This usually means the LoDFactor is set too high for your RAM/VRAM. Revert it to 2.000000.
• Stuttering in Big Cities: This is a CPU bottleneck. Lower your Traffic settings (Airliners, Ships, Road Vehicles) to 20% to free up threads for the streaming data.
• Settings Resetting: MSFS often resets this file after a “World Update.” Once satisfied, right-click UserCfg.opt, select Properties, and check Read-only.

Frequently Asked Questions (FAQ)

Conclusion and Expected Results

By manually refining your UserCfg.opt, you are pushing the Asobo Engine beyond its conservative UI limits. You can expect sharper city skylines, reduced texture popping during low-level flight, and a more consistent visual experience when flying over densely populated areas.