Simheaven OSM = frame drain?

[deetee 164]

I have come to the conclusion that although the Simheaven OSM sceneries are the bees knees visually, in proximity of big cities they just kill my frames. Overflying Boston MA looking down at the city, my fps goes down to 12 - I have to set object rendering to "default" (2nd lowest) to get my frames back over 20. Same for Paris, France! On the other hand with the default scenery I get well over 20 with my object rendering set at "mega-tons" (2nd highest).

 

Is it worth using this otherwise fine OSM if the hit is going to be so bad? Most of my airliner flights start and finish near big cities so smoothness is the key here. Is SH OSM at low settings still better than default at high settings ...? Your thoughts?

[jcomm 5,890]

I don't recall what LOD values are used by default, but there was an hint sometime ago about how to reduce the LOD on simheaven sceneries, to, say, a default of 15NM, which would help softening the impact of this sceneries.

[tonywob 4,768]

The LOD distance is quite high on these sceneries, in my program I've reduced it to 13KM for small buildings and 15KM for tall buildings (Although this is configurable)

 

You can do this manually, although it might take you a few minutes.

 

If you open up the simheaven OSM scenery, open up the folder called facades, and open each .fac file up in a text editor, if you then change the line than reads something line

LOD 0 20000, to LOD 0 15000 for 15KM, then this will do the trick. 

[jcomm 5,890]

Yes, thanks Tony!

 

If you're on Linux, then it's terribly easy :-)

 

I recommend, on Windowze... the use of something like "FAR"

 

http://findandreplace.sourceforge.net/

 

a very useful tool for finding and replacing string occurrences inside files. Here's an example:

 

[tonywob 4,768]

Cool program :-). BTW, if 25000 is the default LOD, then I'm not surprised it struggles in big cities and slower computers

[jcomm 5,890]

if 25000 is the default LOD

 

it is indeed Tony :-/. Reducing to 12000.000000 makes a difference !

 

In FAC you can also use regula expressions for the file names. Here I just looked for the ".fac" files, but we can make a more restrictive search.

[deetee 164]

 

 

I'm not surprised it struggles in big cities and slower computers

If only that were the case Tony, but what bites is that I have a pretty decent new rig!    ^_^

[tonywob 4,768]

Same here, I have to reduce the LOD right down to get it work. In my test scenery for Berlin, I have reduced residential buildings to 12000 and the taller city buildings and factories to 14000. It isn't perfect, but gives a good performance balance. You can do something similar in the LODs, and I would suggest altering all the .fac files ending in house to 12000, and the others to 14000. You should see a big performance boost by doing so.

 

Also, forests are a killer as well, even on powerful machines, so might need to tune that down a notch.

[jcomm 5,890]

One issue that I still hate to see are the street and highway lights popping on / off... Looks awful on the otherwise very nice night scenery rendering of X-Plane ...

[tonywob 4,768]

Yes I know exactly what you mean. (Going off topic) One idea which might get round this, is to actually place 3D light objects onto the facade wall, which has a much higher LOD than the actual facade file and only viewable from a distance, but this is quite difficuilt (as I don't have any lights to use). In effect, you would just see the lights in the far distance, and not the actual object, which maybe OK at night and good for framerates. As you got close enough, the light would switch over to the default facade one and disappear, so that it doesn't look like it's floating in midair.

[deetee 164]

 

 

I have reduced residential buildings to 12000 and the taller city buildings and factories to 14000

This solution is starting to bear fruit! How does one differentiate between the taller and smaller objects in the SH scenery; can we consider the taller buildings to be the "simHeavenB*.fac" variety, and the other "simHeavenH*.fac" the smaller houses?

 

Thanks.

[tonywob 4,768]

Yes, I'd imagine so. The sloped ones should all be reduced as well.

[ryanbatc 12,784]

Oh? This has got to be my problem then. I run OSM (not photorealistic) when flying on pilot edge in the SoCal area, and fps just tank... 15 is about average. And that's with HDR off.

[Anxu00 176]

Interesting read, I disabled OSM to remove unwanted building showing up in my airport (CYOW) and noticed a huge performance gain.  I left it off ever since.  The default is pretty good for me, but I will try the LOD trick later.  I also run at 2560x1600 as well, so I may just leave OSM off.  We 'll see.

[tonywob 4,768]

Seems this is quite a common problem, and I'm trying to think up a solution. In my sceneries (http://forum.avsim.net/topic/433700-introducing-x-plane-scenery-tool), cities even on a low LOD setting (12000) can bring slower computers to their knees. This is because it is treating little buildings such as a garage or shed the same as a highrise block of apartments.

 

I see a simple way around this:

1. Create multiple copies of the facades, each with different LOD settings, e.g.  8000, 12000, 13000, 14000, 15000. 
2. When generating the scenery, calculate the area of each object, and use a simple score based on height and area to calculate the LOD to use. For example, a little garage in a residential area should probably be given 8000, but a block of apartments in the town centre should be given 15,000.
3. Building parts are tricky, as many landmarks in cities are mapped using multiple parts with different heights and areas. It would look odd if some parts of the building disappeared and others stayed. Not sure how to do this one :-)