Ambient Occlusion & Lighting Explained
Estimated Lesson Time: 35–45 Minutes
Lesson Overview
.
In the previous lesson, we explored how shadows affect both realism and performance in Microsoft Flight Simulator.
Now we’re going to look at another important group of graphics settings:
Lighting and Post-Processing Effects.
These settings are responsible for much of the simulator’s visual realism.
They control how light behaves.
How shadows blend together.
How sunlight interacts with objects.
How reflections appear.
How bright lights glow.
How atmospheric effects are displayed.
Individually these settings may appear subtle.
Combined together…
They dramatically improve the realism of the simulator.
Understanding each one will help you decide whether the visual improvements are worth the performance cost.
Lesson Objectives
By the end of this lesson you will understand:
What Ambient Occlusion is.
What Global Illumination does.
What Bloom is.
What Lens Correction does.
How Reflections work.
What Light Shafts are.
Which settings affect the GPU.
Which settings have the biggest visual impact.
Which settings are worth lowering if extra performance is needed.
1. Ambient Occlusion
Ambient Occlusion (AO) is a lighting technique that creates soft shadows in areas where objects naturally block light.
Rather than creating large shadows like buildings or mountains…
Ambient Occlusion focuses on the tiny areas where surfaces meet.
Examples include:
- Cockpit switches
- Instrument panels
- Seats
- Aircraft doors
- Building corners
- Wheel wells
- Landing gear
- Engine nacelles
Without Ambient Occlusion, these areas can look flat and unrealistic.
Example
Imagine looking inside an aircraft cockpit.
Without Ambient Occlusion:
Everything appears evenly lit.
Panels look flat.
Switches appear painted onto the surface.
With Ambient Occlusion:
Small shadows appear around switches and controls.
Buttons have depth.
Panels look more realistic.
The cockpit feels much more three-dimensional.
Performance Impact
Mainly GPU.
Moderate GPU workload.
Very little direct CPU impact.
Visual Comparison
Ambient Occlusion Off
Flat image.
Little depth.
Less realistic cockpit.
Ambient Occlusion On
Greater depth.
Natural shadowing.
More realistic aircraft interiors.
2. Global Illumination
Global Illumination (GI) simulates how light bounces around the environment.
In real life…
Light doesn’t simply hit an object once.
It reflects onto nearby surfaces.
This creates realistic lighting.
Microsoft Flight Simulator recreates this effect.
Example
Imagine sunlight entering a cockpit window.
Without Global Illumination:
Only the direct sunlight is visible.
With Global Illumination:
Light bounces off the dashboard.
The seats become softly illuminated.
The cockpit appears naturally lit.
Where You’ll Notice It
Cockpits.
Airport terminals.
Buildings.
Hangars.
Sunrise.
Sunset.
Night lighting.
Performance Impact
Primarily GPU.
Moderate to high GPU workload depending on scene complexity.
Visual Comparison
Global Illumination Off
Lighting appears simple.
Dark areas remain dark.
Less realistic interiors.
Global Illumination On
Natural light bounce.
More realistic colours.
Improved atmosphere.
3. Bloom
Bloom is a post-processing effect that creates a soft glow around very bright light sources.
Examples include:
Sunlight.
Landing lights.
Runway lights.
Taxiway lights.
City lights.
Cockpit displays.
Bloom makes bright objects appear more natural by allowing light to gently spread beyond its source.
Example
Think about driving at night.
Street lights don’t appear as perfectly sharp dots.
Instead…
They glow slightly.
Bloom recreates this effect.
Performance Impact
Low GPU impact.
Mostly a visual preference.
Visual Comparison
Bloom Off
Lights appear sharp.
Less cinematic.
Bloom On
Lights glow naturally.
Sunsets appear warmer.
Night lighting becomes more atmospheric.
4. Lens Correction
Lens Correction simulates the way real camera lenses affect an image.
Depending on implementation, it can subtly adjust:
Image distortion.
Perspective.
Chromatic effects.
Overall image presentation.
Its goal is to make the simulator resemble footage captured through a real camera.
Should You Use It?
This is largely a personal preference.
Some users enjoy the cinematic appearance.
Others prefer the cleanest, sharpest image possible.
Experiment to see which presentation you prefer.
Performance Impact
Very small GPU impact.
Usually negligible on modern hardware.
5. Reflections
Reflections determine how light reflects from surfaces throughout the simulator.
Examples include:
Aircraft fuselage.
Cockpit glass.
Airport windows.
Water.
Wet runways.
Vehicles.
Buildings.
Higher Reflection Quality produces:
Sharper reflections.
Greater realism.
Improved lighting effects.
However…
Every reflection must be rendered by the GPU.
Why Reflections Are Demanding
The graphics card often has to render parts of the scene again to create realistic reflections.
This increases GPU workload.
Performance Impact
Mostly GPU.
Can become demanding on higher settings, especially in wet conditions or areas with many reflective surfaces.
Visual Comparison
Low
Simple reflections.
Less realistic water.
Duller aircraft surfaces.
High
Sharper reflections.
More realistic aircraft.
Improved water quality.
Better immersion.
6. Light Shafts
Light Shafts are often called:
God Rays.
They simulate visible beams of sunlight passing through:
Clouds.
Trees.
Windows.
Fog.
Atmosphere.
This effect is most noticeable during:
Sunrise.
Sunset.
Heavy cloud.
Storms.
Mountain flying.
Example
Imagine flying through broken cloud at sunrise.
Without Light Shafts:
The sunlight simply brightens the scene.
With Light Shafts:
Visible beams of sunlight shine through the clouds.
The atmosphere becomes much more dramatic.
Performance Impact
Moderate GPU workload.
Minimal CPU impact.
7. CPU vs GPU Impact
Lighting effects are almost entirely handled by the graphics card.
The CPU prepares the scene.
The GPU calculates:
Light.
Shadows.
Reflections.
Bloom.
Ambient Occlusion.
Global Illumination.
Light Shafts.
Therefore…
Most lighting settings are primarily GPU intensive.
Performance Summary
|
Setting |
CPU Impact |
GPU Impact |
|---|---|---|
|
Ambient Occlusion |
Very Low |
Medium |
|
Global Illumination |
Very Low |
High |
|
Bloom |
Very Low |
Low |
|
Lens Correction |
Very Low |
Very Low |
|
Reflections |
Very Low |
Medium–High |
|
Light Shafts |
Very Low |
Medium |
8. When Should You Increase These Settings?
Consider increasing lighting settings if:
- You enjoy VFR flying.
- You fly during sunrise or sunset.
- You enjoy realistic weather.
- You create screenshots or videos.
- You have a powerful graphics card.
- Your GPU has spare performance.
9. When Should You Reduce Them?
Reduce these settings if:
- Your GPU is consistently near maximum utilisation.
- FPS drops during complex weather.
- You fly at 4K on a mid-range GPU.
- You need extra GPU headroom while maintaining good overall visuals.
Cloud Quality, Shadow Quality and Reflections are usually more demanding than Bloom or Lens Correction.
10. Common Myths
Myth 1
“Ambient Occlusion creates shadows.”
Not exactly.
It creates small contact shadows where light naturally becomes blocked.
Myth 2
“Bloom improves FPS.”
False.
Bloom is purely a visual effect.
Myth 3
“Reflections only affect water.”
False.
They also affect aircraft, buildings, windows, wet surfaces and more.
Myth 4
“Lighting settings mainly affect the CPU.”
False.
Lighting calculations are primarily performed by the GPU.
Student Exercise
Today we’re going to compare Lighting Quality.
Step 1
Load your Module 1 benchmark flight.
Use:
- Same airport.
- Same aircraft.
- Same resolution.
For best results, choose a flight during sunrise or sunset to make lighting differences easier to observe.
Step 2
Compare:
- Ambient Occlusion
- Reflections
- Bloom
- Light Shafts
Where possible, switch individual settings between Medium, High and Ultra.
Step 3
During each test, record:
- Average FPS.
- Lowest FPS.
- GPU utilisation.
- GPU temperature.
- Cockpit realism.
- Reflection quality.
- Lighting realism.
- Overall smoothness.
Step 4
Compare the results.
Ask yourself:
- Which lighting effect improved realism the most?
- Which setting had the greatest impact on GPU performance?
- Were any visual differences too subtle to justify the performance cost?
- Which combination provides the best balance for your hardware?
Student Checklist
Ambient Occlusion tested.
Global Illumination observed.
Bloom compared.
Lens Correction evaluated.
Reflections reviewed.
Light Shafts compared.
GPU utilisation monitored.
Best lighting settings selected.
Lesson Summary
Congratulations.
You now understand how lighting effects transform the appearance of Microsoft Flight Simulator.
Remember:
- Ambient Occlusion adds depth by creating soft shadows where surfaces meet.
- Global Illumination simulates light bouncing naturally around the environment.
- Bloom creates a soft glow around bright light sources.
- Lens Correction subtly changes the way the image is presented and is largely a matter of personal preference.
- Reflections increase realism on aircraft, water and buildings but can be GPU intensive.
- Light Shafts create dramatic beams of sunlight through clouds and atmosphere.
- Nearly all of these settings are primarily GPU limited.
- The best configuration is the one that provides convincing lighting without overloading your graphics card.
Knowledge Check
- What is Ambient Occlusion, and how does it improve realism?
- How does Global Illumination differ from standard lighting?
- What visual effect does Bloom create?
- Why are Reflections more demanding than Bloom?
- What are Light Shafts, and when are they most noticeable?
- Which hardware component is mainly responsible for these lighting effects?
- Which lighting settings would you reduce first if your GPU became the limiting factor?
- Based on your benchmark testing, which lighting settings gave you the best balance between visual quality and performance?