Cool, apologies if *I've* come across a bit defensive then. I think you're doing fine work, as I'm sure many other players agree.

No need to delete anything grim, lots of good information from you in here. Rather technical points as I just needed you to say you love it and thanks for creating it, we're all human :) - but very interesting - thanks!

If you want to actually have a reasonable discussion about it, that's fine too. I can see that there is *some* peaking around certain histogram values in the raw images from terrain.party, so presumably there is some form of up-conversion from lower precision data going on with the underlying DEM data sets. It appears to be non-linear (bands seem slightly logarithmically distributed), so it still wouldn't be a good idea to store it in an 8-bit integer file as that would cause quantization artifacts. But anyway, I presume that may be what you were referring to regarding the ~100 level observation.
My point was only ever that whatever the source, 8-bit greyscale is inadequate to represent final terrain inside Transport Fever, which your mod demonstrates perfectly as it *is* 16-bit and clearly wasn't down-sampled to 8-bit during processing.

I'm not sure one of my maps will be much use, as I generated them both from scratch in full 32-bit floating point, ran them through World Machine's erosion modelling, and down-converted them to 16-bit integer.

Look, it's clear you're annoyed. I presume you don't appreciate this discussion thread spilling over the comments section of your own mod.
When all said and done, I was only attempting to offer some clear advice to someone who asked, advice that didn't implicate you in any bad practice, given your mod follows that advice.
It was you who chose to openly disagree with my advice, to take offense where none was intended when I disagreed in turn, and to then continue to fight me on it.

At this point, the user asking the initial question has surely read the answer, so I'm happy to delete my comments from your page if you would prefer me to.

Thank you for checking my own map and suggesting that I may be giving incorrect information and don't know what I'm doing. Now can I see one of your maps please, I have much to learn apparently

@Bresslaw
Nothing of the sort, I was just trying to give advice to jo3do88y below, and suggest that you may be giving incorrect information yourself.

I just checked your own map... the heightmap.png included is a 16-bit integer greyscale image, and it contains values from ~2100 to ~34000... so it's employing around 32000 unique shades.
- That's why it looks smooth.

256 shades would be completely inadequate to depict the map you have here... and that is specifically why some other maps appear obviously divided into discrete terraces.


Perhaps check the facts before getting too defensive.

Grimfandango you said "256 levels is absolutely inadequate" but I already told you that terrain.party's images are around 100 levels. Are you saying that you don't like my work? It's inadequate? Very odd comments in a free map mod comments section

Interpolation...

Hmm, no... I just went at checked a terrain.party download, for some random spot in central USA, with Houdini (a package with a fully 16-bit aware compositor, not to mention ). The files are all 16-bit integer, values ranging from 0 to 65535, and a histogram clearly shows that values are spread across that range, not banded.
Easy test - try loading one of the png files in Windows Paint (definitely a non-16-bit-aware package), then re-saving without altering anything. The resulting file will be considerably smaller than the original, as it compresses the bit depth down to 8-bit.

256 levels is absolutely inadequate. Transport Fever works with a height range of 1000m or more - which means each height level would be around 4m - ie, half the height of a house! The stepping is very noticable when you use an 8-bit heightmap, especially on any map with significant hills/mountains... it'll end up looking like Machu Picchu.

The only thing I find with terrain party's maps is they're quite small in TPF, is there any way to make them bigger without using a image editing programme?

Fantastic thanks Bresslaw!

8bit is 256 greyscale levels, not too bad with intelligent software processing grim. terrain.party returns 8bit terrain elevation levels. I'm pretty sure that 16bit terrain is a dream for now - although did you see Colonel Failure's theme park broadcasts? In the background is very beautiful terrain, cross fingers in a future TS :)

Out of interest I checked the returned images from terrain.data grim, and most have around 100 grey-scale levels. This will probably be a limitation of the satellite's hardware as it appears to be raw data, can be quite noisy and even obviously blurry as if something hit the satellite at the moment of shutter release, meteor-jog maybe :)

256 levels for terrain would be delicious. USGS images btw I haven't checked but they too are variable, see the Gold Mountains

@Bresslaw
I thought terrain.party exported 16-bit integer greyscale? It says that's the format that Cities Skylines uses, in the readme.txt included with downloads.

I figured the problem is that a lot of basic/freeware image editing packages will load those files, but only output an 8-bit result, so you end up losing all that detail.

16bit terrain - we wish grim :)

terrain.data's downloads are intrinsically smooth jo, but you must work with the source material unedited to get the best out it. Paint apps tend to operate on the loaded image without being invited

@jo3do88y
The stepping effect is because you're using maps with 8-bit colour data... which at most gives 256 discrete heights, if it uses the full black-to-white range.
You need to use 16-bit data, which will have up to 65536 height values to work with instead. You have to make sure the source, and any editing steps all work in 16-bit. If at any stage it gets compressed down to 8-bit, you'll lose the smooth detail.

Ah yes, Minekopf

Fantastic map! Just one question, How do you get your maps so smooth? Whenever I use terrain party they're all... step like :D Thanks!