I think I found the cause of the disappearing cloud shadows

[OliverDK 0]

It seems that only the clouds in frame have their shadows rendered.
 
Couldn't find any references to this. Let me know if it has been posted before, and I'll take it down.
 

[mwilk 1,104]

I think there are a lot of methods employed to squeeze the last bit of performance out of P3D. This may be one of them. Another is that AI traffic is rarely ever visible in P3D unless you're right on top of it.

[OliverDK 0]

Maybe. But the consequence of this is that when the sun is low on the horizon you won't see cloud shadows when looking to the side or not travelling towards the sun. I'm not sure why those situations would be particularly hard on your frames.

[jabloomf1230 2,445]

Another is that AI traffic is rarely ever visible in P3D unless you're right on top of it.

 

 

The visibility of AI traffic labels in P3d is supposedly 10 nm. When using Tacpack, it seems to corroborate that oft-repeated statement. One thing that controls the visibility of unlabeled distant AI aircraft is whether they contain the minimum number of pixels to be visible. I've read conflicting reports of what the default value for:

 

[sCENERY]

…

SmallPartRejectRadius=n

 

is in FSX. Some say it is 1, but others say it is 2. Further, there is another school that says using 0 gives the maximum visibility of AI aircraft. And what's the default value in P3d? Maybe Rob A. knows. The V2 SDK docs say the default is 1, but the V3 SDK doesn't say anything that I could find easily.

 

EDIT:

 

I did want to add something that I forgot initially. Models in FSX/P3d commonly have multiple levels of detail (LOD). As the object is further away from the viewer, the models become more and more simplified, in terms of the numbers of vertices and faces. For example, the FAIB Airbus 320 model has 6 LODs (5, 15,35,75,150 and 400). Although one would think that the size of the object would not change with LOD, it in fact does, as the 2nd lowest LOD of the A320 consists of a 2D fuselage glued to 2 2D wings. The LOD5 model consists of only light effects.

[aeronauta 66]

Jay V3 says also 1...(from the learning center)

 

In Prepar3D.cfg, in the [Graphics] section, the following two settings can affect performance:

SmallPartRejectRadius=N (default is 1) which determines the radius in pixels that an object has to be in order to be rendered. Increasing this size will cull more objects from the rendering pipeline.

 

Jorge

[jabloomf1230 2,445]

Thanks Jorge. They must have moved where the entry was located in the V3 SDK and it is supposedly now in the [GRAPHICS] section, unlike FSX.