#2625 LOD slider buggy for AI/MP interior (probably degrading performance heavily!)

[Benedikt Hallinger]

Hello,
today Marius found an interesting issue with the LOD settings, which may also explain some strange phenomena we had the last weeks flying on our wednesday GA trips.

In short:
We believe the "AI/MP interior" slider is behaving the wrong way around.
It seems, that the setting results in the detailed cockpit being rendered when the plane is further away than the setting in meters.
I think that the setting should define, what is the maximum distance the detailed interior will be rendered.

There is a detailed report at github, please read it, there is everything there with screenshots etc, explaining the issue.

Consequences:
This means that nearly every AI/MP plane will command the detailed interior to be rendered, maybe partly explaining the performance hits we see when flying with several pilots, and also why some models are worse then others. This is hard to see in the sim, however, because at 200 meters away (the default setting!), the interior is not really properly visible anymore, so the issue is not easily uncovered

For the C182s this is a prominent bug, because the default low poly core model has a different offset than the detailed one.
The low poly core model sinks into the ground, making the (wrongly) displayed detailed interior stand out at the roof.

Proposed solutions:

1. Fix the behaviour of the LOD calculator:reverse the interpretation of the "AI/MP interior" sliders value, so it hides detailed interiors further away then x meters
2. Make the default settings of the slider agree to the Low-resolution MP models distance, so both disappear at the same distance (or detailed interior even earlier)
3. Also adjust the core C182 low poly MP model Z origin, so it does not sink into the ground anymore

---

References:

• Details, screenshots, analysis etc: https://github.com/HHS81/c182s/issues/428
• maybe related to: https://sourceforge.net/p/flightgear/codetickets/2411/
• maybe related to: https://sourceforge.net/p/flightgear/codetickets/235/

[Benedikt Hallinger]

The c182 detailed model references "3" as fallback model in its set file:
<fallback-model-index>3</fallback-model-index>

[Benedikt Hallinger]

To make the solution-part "2." more clear, I wanted to also imply:
When Flightgear decides to render the low-poly fallback, never render the detailed interiour model too.
The slider should therefore be some kind of "render detailed interior up to that distance, but never further away than the detailed exteriour is shown"

[James Turner]

Pining Stuart about this one.

[Benedikt Hallinger]

Hi, not sure if this is still open.
AFAIK Mariusz did work on this issue and probably fixed it already.

[James Turner]

It's still open: Benedikt does this mean we can definitely close the ticket, or you prefer someone checks a bit more?

[Benedikt Hallinger]

I think Mariusz should be able to tell us - i ask him on the forums.

[Benedikt Hallinger]

Mariusz said, its all in next.
We can close this one here :)

[Mariusz Matuszek]

Yesterday, during our MP event I had a deja'vu feeling.
Either there is a regression, or there is another issue with the model, showing the same behaviour.
Screenshots and version details are in a forum post here https://forum.flightgear.org/viewtopic.php?f=10&t=39025&p=411663#p411663