IMAGE_COMPLEXITY – scenery complexity setting

IMAGE_COMPLEXITY setting in fsx.cfg and scenery complexity slider in FSX settings. How to set it for the best performance and quality?

High setting at Phoenix Airport

High setting at Phoenix Airport

FSX tweak guide

Difficulty: difficult

Effect on performance: possibly

Effects on quality: yes

Good for: I suggest you just set it once and forget about it

Recommended setting (all users): far right slider position / IMAGE_COMPLEXITY=5


IMAGE_COMPLEXITY vs Scenery complexity slider

IMAGE_COMPLEXITY code in fsx.cfg shows the position of the Scenery complexity slider in FSX settings.

IMAGE_COMPLEXITY=5 – Extremely Dense


How it works?

How it should work?

The main reason for this setting was to allow scenery developers to build sceneries with adjustable complexity. Each object would appear only if required level of complexity was set. In theory – a scenery would be scalable and user would be able to adjust it’s complexity and it’s load on his PC.

How it actually works?

If you test a default scenery at various Scenery complexity setting – you will see a difference.

Not so much with payware sceneries. I tested several and I never noticed more than three levels of complexity. Take a look at this examples.

Scenery complexity at TNCM – St. Maarten (FlyTampa scenery – read my review)

Spot the difference

Spot the difference

To spare your time I’ll share my observations. There is no difference between 2 (Normal) and 5 (Extremely dense). If you set Scenery complexity slider to Sparse (IMAGE_COMPLEXITY=1) 3d lights and 3d grass will disappear. Set it to Very Sparse (IMAGE_COMPLEXITY=0) and parts of the jetways will disappear too. In terms of scenery performance and load – there is not much of a difference between 1 and 2 and I could not see a slightest difference in performance between 0 and 1.

Scenery complexity at EPLL – Łódź (Drzewiecki Design)



As you can clearly see – the difference is huge! It’s just an empty scenery with only ground textures left at Very sparse and Sparse settings (IMAGE_COMPLEXITY=0 and =1). At or above 2 (slider position between Normal and Extremely Dense) there is a complete scenery.

Effects on performance

It depends on the scenery you use. There may be some sceneries that actually use this setting to improve performance in the way it was intended. Further test would be necessary.


Look for scenery configurator

What Microsoft tried to achieve with this setting is usually realized with scenery configurator tool that allows to turn on or off the features that cause excessive load.

Use “far right” slider position (Extremely dense / IMAGE_COMPLEXITY=5)

Until you encounter problems with a scenery that actually use all this levels and includes some heavy objects at Extremely dense setting – you should stick with it just to make sure that you see all the objects in the scenery.


IMAGE_COMPLEXITY - scenery complexity setting
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IMAGE_COMPLEXITY - scenery complexity setting
IMAGE_COMPLEXITY setting in fsx.cfg and scenery complexity slider in FSX settings. How to set it for the best performance and quality?