Balearic Islands Prof - Stutters in v4/v5 over water caused by legacy waterpolys

[Yves77 2]

Hi,

 

I have been experiencing heavy stutters in the sense of high frame variations (within a second) in P3D v4 and v5 in Mallorca, Menorca and Ibiza. They only happen when (any) airplane is flying over the water around the islands (e.g on final LEPA RWY 06). Over land the performance is smooth. The transition is always exactly over the coastline. I could trace the issue down to the three files LEPA_CVX-Terrain.BGL, LEMH_CVX-Terrain.BGL and LEIB_CVX-Terrain.BGL. If you disable them, the stutters are gone.

 

I then had a look at them with TMFviewer (s. picture). The stutters appear when the aircraft is over the blue area, which defines the water polygons of each island (there are also exclusion areas and airport bounds in the files). The water poly used is of old FS2004 type (LWM) and it seems that P3D is not efficient in rendering these. For FSX/P3D there exists a different type of water poly which does not induce stutters. Sim-wings (and most other developers) have already used this type e.g. in the Gran Canaria Prof and La Palma Prof sceneries.

 

Is it possible to get an updated version of the three files? I am not sure if they even are required as I have not seen yet a visual problem with water or exclusion. Without the files, there are now waves at the beaches.

 

Regards,

Yves

 

 

Technical info:

The water poly GUID in the three CVX-files refers to the following entry in terrain.cfg (default and ORBX):

 

// Legacy_LandWaterMask_Water_NoFlatten
[Texture.381]
Name=Legacy_LandWaterMask_Water_NoFlatten
Color=FF638AC2
guid={5835459A-4B8B-41F2-ADC1-DEE721573B28}
Textures=OCEAN_SEA_LARGE_LAKE_0
FlattenMode=none
LandClassRemapType=none
ExcludeAutogen=Yes
RenderToTexture=Yes
RenderPriority=80000
Water=Yes

 

In Sim-wings Gran Canaria Prof the file GC_CVX-Terrain.bgl uses the newer FSX/P3D entry:

// Hydro Polygons - Generic Ocean - Perennial
[Texture.199]
Name=Hydro_Polygons_Generic_Ocean_Perennial
Color=FF2938FF
guid={2D103429-89EB-4CB3-A61E-E188E79C77E7}
Textures=OCEAN_SEA_LARGE_LAKE_0
FlattenMode=slope
FlattenPriority=41000
ExcludeAutogen=Yes
RenderToTexture=Yes
RenderPriority=81000
Water=Yes

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[OPabst 2091]

I will have a look into it.

[OPabst 2091]

First, I could not reproduce any performance differences, when I change the Waterclass here.

And that is what is to be expected. The name of the classdefinition is not relevant for anything within the Sim. And he don't render this class with "older" code. It is only a different parameter, based on the definition existing since long time.

When you check the entries in the terrain.cfg you will see, that the only difference between the "Hydro_Polygons_Generic_Ocean_Perennial" named entry and the "Legacy_LandWaterMask_Water_NoFlatten" is the parameter

""FlattenMode=", which is in the Hydro_.... definition set to slope and in the Legacy... set to none

The difference is only the the "Legacy_LandWaterMask_Water_NoFlatten" class, as the name says, don't flatten the mesh below the poly. Visual is no difference. So I don't see any reason, why this class should result in slow frames here.

 

But, you can check it yourself. Make a backup of the LEPA_CVX-Terrain.bgl and replace it with the file in the attached zip. There I have change the class to Hydro_Polygons_Generic_Ocean_Perennial

The file is not usable, as it flatten the cost, but to check if the frames are different, what I don't see here, you can make the test.

 

When you remove the file, you will may not see the difference, as long as you don't go in detail. Without the file, the landclass of the island below the Photoreal ground of the scenery will be visable at some areas of the cost. The Waves are visable, but with the high resolution mesh it looks not very nice, if the waves will climb up the costline.

You could not place the shoreline so exacly along the mesh of the cost, that it is looking good.

 

So, I would not expect a differnce with the changed file, but as you seams not to use the default terrain.cfg (the texturenames are different to the original once), I could not say what changes on you system may be the reason for frame issues over the sea.

Test Waterclass for LEPA.zip

[Yves77 2]

Thank you very much for looking into this issue. I have been testing your new file in v5.0 HF2 also with focus on the order it may be read in P3D by renaming and moving files between disks, but I have not a clear result yet. So far, it does not look to improve the situation. Only disabling it helped.

When I fly from Palma Airport to the main cruise harbour in Palma and then continue along the coastline the frame variations are very noticable. I also set all sliders to the left and disabled any option in the menu. My RTX2080 Super had almost nothing to render with 200-300 fps, but the stutters remained whenever the plane was over the waterpoly. Even when slewing up to 20K feet they stayed. I use ORBX with LC Europe (no VECTOR).

 

It is fully reproducible and I will continue testing and report here.

Yves

[Yves77 2]

I did some further testing with the old and new CVX file in v5, but the stutters happen with both of them. I disabled all other Mallorca files and just kept the CVX Terrain file and even then the stutters remained. To see the large frame variations you need to set Texture Resolution slider to 30, 15 or 7 cm (at 60 cm and higher they are barely noticable). Then fly in the Bay of Palma, heading from LEPA to the cruise ships and then along the coast to SW. Even in slew mode I can see the extreme

jerky movement in spot view. They are less pronounced in Menorca and Ibiza.

 

Then I did some more analysis. When looking at the three Balearic CVX Terrain files in TmfViewer, I see that the water polys were designed with a different drawing technique than other CVX files (default and addons). In other sceneries (e.g. Sim-wings Gran Canaria) a water polygon always covers a full QMID 11, 12 or 13 cell (except for the coastline) along the cell borders. In the Balearic files the polys stretch across multiple cells and some are overlapping each other (see comparison screenshot).

I could only find one other addon (Madeira Evolution) where a water poly does not fully cover a QMID 11 cell and only in this specifc cells there are the same stutters. In Madeira it is the most outbound line of polys about 100 km from the island, clearly visible as diagonal lines at the top and sides in the second screenshot.

 

This is my best guess. P3D seems to struggle with cross-bordering and overlapping polys.

 

Yves

 

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