P3D v4 Water blend mask - Gradient issues

[dgpilot1]

Hi all,

Has anyone had this issue before? I'm making a simply blend mask for PR water. The mask works... but shows this awful gradient. In TMFviewer, the gradient is perfectly smooth.
(ignore the red - testing purposes only)



Things I've tried:

- Tiff image compression, LZW and none
- BMP
- Increased compression quality in INF
- Disabled any graphical tweaks such as PTA/Reshade

 

[GaryGB]

Hello:

IIUC, what we see in your screenshot is "banding" in the gradient steps of a 8-Bit gray-scale *.Tif Blend Mask.

That file format yields a smaller source data contribution to output BGL size, but in water areas may show 'banding' ...unless it is modified.


IIRC, the best method to minimize this 'banding' is to modify the 8-Bit gray-scale *.Tif Blend Mask by using a graphics application to apply Floyd-Steinberg dithering to a copy of the original, and using the resulting file instead of the original.

https://en.wikipedia.org/wiki/Floyd–Steinberg_dithering


Alternatively, you may try a 24-Bit RGB Blend Mask format with- or without- applying Floyd-Steinberg dithering,

GaryGB

 

[HolgerSandmann]

Hi there,

how high did you go with the compression value? In my experience it needs to be at least 90 for PR water to avoid visible banding.

Cheers, Holger

 

[dgpilot1]

Thanks for the replies. I've tried all these solutions but there is still visible banding. It seems this has always been an issue, if you look at default TNCM there is massive banding as well.. so I suppose it's a sim limitation.
The interesting thing is the SDK documentation shows an example where there's a perfectly smooth gradient. I tried to even replicate this and doesn't seem possible. Wonder how they managed that?

 

[HolgerSandmann]

Hi again,

see my banding-free examples below. The first two screenshots show 10-m Sentinel2 imagery, upsampled to 5m (needs to be compiled at LOD14 anyway) and the third 1-m USGS imagery compiled at LOD16.

I'm not doing anything special with the blendmask. I select the desired outer extent with the lasso tool in Photoshop and then use a suitable feathering value, for water areas usually 40 to 200, prior to filling the blendmask.

I prefer to have both watermask and blendmask directly in my Photoshop tiff as Alpha1 and Alpha2 channels, respectively, though external masking files should work just as well. Obviously, the watermask is fully black.

CompressionQuality is set to 90 for PR areas with water.

Cheers, Holger

 

[FrancisJohannes]

Hi guys,

What happens if I forget to make the masks from FS EARTH Tiles and I've worked hours on beautifying my future ground poly, Is there a work-around ?

Thanks.