Height of heightmap changed on import?

[Krileon]

I'm importing a heightmap from WorldPainter which is a heightmap painting tool for Minecraft, which uses 8bit BMP for its 256 height range (1m is 1 block so 256 block height). I'm wanting to use this tool to import a heightmap from L3DT, but my problem is that L3DT always has a much much higher height range than 256. My guess is it's always exporting as 16bit. Is there anyway I can limit the height range properly? I've tried various parameters like vertical range and horizontal scale (believe this needs to be 1m). Below is an example of what happens when I import from WorldPainter and what it turns into.

Original BMP before import:

original.jpg (39.84 KiB) Viewed 15091 times

After import into L3DT:

l3dt.jpg (192.34 KiB) Viewed 15091 times

As you can see the height range changes drastically so something is clearly changing the grayscale range or something of the sort.

[Aaron]

Hi Krileon,

The bitmap exporter is automatically rescaling the heightfield such that the heights in the map span the 8-bit colour range from black to white, for maximum precision. This means that the lowest height will be written to the file as 0, and the highest as 255. This will occur even if the highest point in your heightmap is only, say, 127m (as seems to be the case in your 'original' map).

It is not converting to 16-bit, as this is not supported for the bitmap format exporter (unless you select the G16-BMP format, which I assume you didn't).

I'll modify the bitmap exporter to give you control over the output height range, including disabling the auto-scaling. I'll post back here when the update is available.

Best regards,
Aaron.

[Krileon]

Absolutely awesome! I'm still on free trial, but give it a few minutes and my purchase will come through. Wonderful software.

[Krileon]

Any sort of ETA on this feature if you don't mind me asking?

[Aaron]

Hi Krileon,

I apologise for the delay in my reply. It's very difficult to give a meaningful ETA, but were I forced to guess, I'd say January, plus or minus three months (mostly plus).

Best regards,
Aaron.

[Krileon]

Ok, thank you; no worries as I've another project am working on first before the project that'd need this.

[Aaron]

Hi Krileon,

I apologise for the delay. In the latest build of L3DT (v13.10.0.1, on the downloads page now), you can now set the output greyscale range so that L3DT doesn't always make your bitmap span from 0-255.To use this feature, open the export wizard, select the bitmap format, then select the 'Options...' button. In the options window, edit the Export->MinGreyscale and Export->MaxGreyscale values (double-click to edit, -1 = default value).

Please let me know if you find any problems.

Best regards,
Aaron.