Object Level of Detail (Object LOD)
Estimated Lesson Time: 30–40 Minutes
Lesson Overview
In the previous lesson, we explored Terrain Level of Detail (Terrain LOD), one of the most important CPU settings in Microsoft Flight Simulator.
Now we’re going to look at another setting that is often confused with Terrain LOD:
Object Level of Detail, commonly known as Object LOD.
While Terrain LOD controls how far detailed terrain is generated, Object LOD controls how far away detailed 3D objects remain visible.
These include:
- Buildings
- Trees
- Airport structures
- Bridges
- Towers
- Street furniture
- Wind turbines
- Industrial buildings
- Hangars
- Other scenery objects
Increasing Object LOD can make the world appear richer and more realistic by allowing detailed objects to remain visible much further into the distance.
However…
Just like Terrain LOD…
This comes at a performance cost.
Understanding how Object LOD works will help you build a simulator that looks detailed while maintaining smooth performance.
Lesson Objectives
By the end of this lesson you will understand:
What Object Level of Detail is.
How it affects buildings.
How it affects trees.
How it affects airport objects.
What draw distance means for scenery objects.
How Object LOD affects CPU workload.
How it changes the appearance of the world.
How to choose the correct Object LOD for your PC.
1. What Is Object Level of Detail?
Object Level of Detail determines how far away detailed 3D objects remain visible.
Unlike Terrain LOD…
Object LOD focuses on everything placed on top of the terrain.
Think of the world around your aircraft.
The ground itself is only one part of the scenery.
On top of that ground are thousands of individual objects.
Every one of those objects must be:
Loaded.
Positioned.
Managed.
Rendered.
Object LOD controls how much of that work is performed around your aircraft.
Think Of It Like Looking Across A City
Imagine you’re approaching London at 5,000 feet.
With a low Object LOD…
Only the buildings close to your aircraft remain fully detailed.
Further away…
Buildings may become simplified or disappear.
With a high Object LOD…
Large parts of the city remain detailed all the way toward the horizon.
The skyline looks much more realistic.
2. Buildings
Buildings are one of the biggest areas affected by Object LOD.
Examples include:
- Houses
- Skyscrapers
- Warehouses
- Office buildings
- Factories
- Shopping centres
- Apartment blocks
As Object LOD increases…
Buildings remain detailed much further away.
Instead of suddenly appearing close to the aircraft, they gradually become visible over a greater distance.
Low Object LOD
Buildings appear later.
City skylines may look sparse.
Objects can “pop in” as you approach.
High Object LOD
Buildings remain visible for much longer distances.
Cities appear fuller.
The skyline looks more natural.
Pop-in is reduced.
3. Trees
Trees are another major part of Object LOD.
Forests contain thousands of individual tree models.
Each tree is an object.
Higher Object LOD allows forests to remain dense further into the distance.
Low Object LOD
Forests thin out earlier.
Tree lines appear shorter.
Individual trees become simplified quickly.
High Object LOD
Large forests remain visible.
Mountain forests look more realistic.
The landscape appears richer during VFR flying.
4. Airport Objects
Object LOD has a significant effect on airports.
Examples include:
- Hangars
- Jetways
- Light poles
- Fuel tanks
- Service vehicles
- Terminal buildings
- Cargo facilities
- Static aircraft (where applicable)
- Airport signage
Busy airports already place heavy demands on the simulator.
Increasing Object LOD means these objects remain detailed over a larger area.
This improves immersion but increases the amount of work required.
Example
Imagine flying into Frankfurt Airport.
With a low Object LOD…
Some airport structures may only appear as you get closer.
With a high Object LOD…
The airport environment becomes visible much earlier, making the arrival feel more realistic.
5. Draw Distance
Draw distance refers to how far from your aircraft the simulator continues to display detailed objects.
Object LOD directly affects this distance.
Low Draw Distance
Objects appear later.
Buildings disappear sooner.
Forests become less dense in the distance.
Large cities appear emptier.
High Draw Distance
Buildings remain visible.
Forests extend further.
Airports remain detailed from greater distances.
The world feels larger and more alive.
6. CPU Load
Object LOD is primarily a CPU-heavy setting, although the GPU also has work to do when rendering the additional objects.
Before the graphics card can draw a building or tree…
The CPU must:
Load it.
Position it.
Manage it.
Determine when it becomes visible.
Handle LOD transitions.
The more objects the simulator prepares…
The more work the CPU performs.
Why Does CPU Usage Increase?
Imagine organising a football tournament.
Managing:
20 players
is easy.
Managing:
2,000 players
takes much more organisation.
Object LOD works the same way.
The more objects the CPU has to manage…
The greater the workload.
7. Visual Differences
Object LOD has one of the biggest visual impacts during low-level flying.
Examples include:
VFR sightseeing.
Helicopter operations.
Bush flying.
General Aviation.
You may notice:
More complete city skylines.
Larger forests.
Reduced object pop-in.
More realistic approaches.
Greater immersion.
At higher cruising altitudes, the visual difference may be less noticeable than during low-level flight.
8. Object LOD Values
Microsoft Flight Simulator allows you to adjust Object LOD using a slider.
Object LOD 50
Lowest CPU workload.
Reduced draw distance.
More noticeable object pop-in.
Suitable for lower-end systems.
Object LOD 100
Balanced.
Good performance.
Recommended starting point.
Object LOD 150
Improved city detail.
Longer draw distances.
Moderate increase in CPU workload.
Suitable for many modern gaming PCs.
Object LOD 200
Excellent visual quality.
Large draw distance.
Higher CPU demand.
Ideal for more powerful processors.
Object LOD 300+
Maximum object visibility.
Outstanding immersion.
Very demanding on the CPU.
Recommended only for high-end systems that maintain smooth performance.
9. When Should You Increase Object LOD?
Increase Object LOD if:
- You mainly fly VFR.
- You enjoy sightseeing.
- You fly helicopters.
- You have a powerful CPU.
- You have spare CPU headroom.
- You want richer city environments.
10. When Should You Reduce Object LOD?
Reduce Object LOD if:
- You are MainThread limited.
- Busy airports stutter.
- Large cities reduce performance.
- You experience inconsistent frame pacing.
- Your CPU is already under heavy load.
Lowering Object LOD can reduce CPU workload while still maintaining good visual quality in many situations.
11. Terrain LOD vs Object LOD
Many users confuse these settings.
Here’s the difference:
Terrain LOD
Controls:
- Terrain
- Mountains
- Hills
- Ground detail
- Terrain mesh
- Distant landscape
Object LOD
Controls:
- Buildings
- Trees
- Airports
- Bridges
- Towers
- Scenery objects
- Forest density
- City skylines
Together, these two settings define how detailed the world appears.
Finding the right balance between them is one of the most effective ways to optimise Microsoft Flight Simulator.
Student Exercise
Today we’re going to compare Object LOD values.
Step 1
Load your Module 1 benchmark flight.
Use the same:
- Airport
- Aircraft
- Weather
- Resolution
- Graphics settings
Step 2
Test:
Object LOD:
- 100
- 150
- 200
If your system has sufficient CPU performance, you may also test 300.
Step 3
During each flight, record:
- Average FPS
- Lowest FPS
- MainThread status
- CPU utilisation
- Building detail
- Tree draw distance
- Airport object detail
- Overall smoothness
Step 4
Compare your results.
Ask yourself:
- Did buildings remain visible further away?
- Were forests noticeably denser?
- Did airport environments appear more realistic?
- Did increasing Object LOD reduce performance?
- Which setting offered the best balance for your PC?
Student Checklist
Object LOD tested.
CPU usage monitored.
MainThread status recorded.
Building draw distance compared.
Tree density evaluated.
Airport object detail reviewed.
Best Object LOD selected.
Lesson Summary
Congratulations.
You now understand the purpose of Object Level of Detail.
Remember:
- Object LOD controls how far away detailed 3D objects remain visible.
- It affects buildings, trees, airports and many other scenery objects.
- Increasing Object LOD improves immersion by reducing object pop-in and extending draw distance.
- It primarily increases CPU workload because the processor must manage more scenery objects.
- Terrain LOD and Object LOD work together but control different parts of the simulator.
- The best Object LOD setting is the one that provides rich scenery while maintaining stable frame pacing and smooth performance.
Knowledge Check
- What does Object Level of Detail control?
- How is Object LOD different from Terrain LOD?
- Why does increasing Object LOD increase CPU workload?
- How does Object LOD affect buildings and city skylines?
- What effect does Object LOD have on trees and forests?
- Why are busy airports more demanding when Object LOD is increased?
- When should you consider reducing Object LOD?
- Based on your benchmark testing, which Object LOD setting provided the best balance between visual quality and performance?