Invert Height map?

[TorQueMoD]

Hey guys!
I tried searching around the forums here for the answer to my subject but wasn't able to find anything.

Does the program have a feature to invert the current height map? I tried exporting a bitmap, inverting it in Photoshop and then re-importing but after PS saves the file it won't import back into L3DT anymore.

Thanks!

[Aaron]

Hi TorQueMoD,

The traditional way to invert the heightfield in L3DT is to select the 'Operations->Heightfield->Change vertical range' menu option, and swap the values in the min. alt. and max. alt. fields.

I've added a script to the the next developmental build to invert the heightfield via a couple of mouse clicks.

By the way, can you tell me what error L3DT threw when you tried to load the bitmap from PS? I'm not aware of any incompatibilities with the bitmap plugin, so it would be useful to see the error log from this event.

Best regards,
Aaron.

[Telarus]

I get the .bmp error as well (I've taken to using png for import, mostly).

A 24bit rgb .bmp (256 * 256px... I rendered 'clouds' in PS with full black and full white, so it's just shades of grey) gives this error:

Code: Select all

L3DTio_BigBitmap::LoadMapFile error:
 - bitmap data size mismatch (196610 reported, 196608 expected)

CMapGroup::LoadMapFile2 error
 - error loading file

After converting to 8bit greyscale .bmp, I get this error:

Code: Select all

L3DTio_BigBitmap::LoadMapFile error:
 - bitmap data size mismatch (65538 reported, 65536 expected)

CMapGroup::LoadMapFile2 error
 - error loading file

[TorQueMoD]

Yes, that's the same error I got but the numbers were obviously different. I'll try a PNG next time.

Thanks Aaron.

[Aaron]

Hi Guys,

Thanks for the bug report. I tested the bitmap importer/exporter against 8- and 24-bit bitmaps from the GIMP, Paint.NET and MS Paint, and it worked in each case. However, I don't use don't use PhotoShop, so I've not had the opportunity to test the bitmap plugin against PS exports. From the error log it looks like Photoshop is padding with an additional two bytes. By pulling apart the example file I should be able to work out what they're doing differently and update the importer accordingly. Could I ask you to please send me an example PS bitmap for testing? Preferably a small one that won't load in L3DT. Zipped, if you please, and sent to aaron@bundysoft.com. Ta.

Best regards,
Aaron.

PS: As a general rule, I strongly recommend against using image formats to store heightfield data. In particular, 8-bit and 24/32-bit images have only 256 possible greyscale values, and this quantisation will introduce nasty terraces in your map. 16-bit greyscale formats are better (PNG, RAW), and if you must use an image format then these are the ones to go for, but they nonetheless drop the altitude & horizontal scaling data out of the file (as all image formats do, except GeoTIFF). Furthermore, editing these images in an image editor in 8- or 24/32-bit modes will also bake the terraces into the heightmap, regardless of what file formats you use. Ah, but now I'm sounding like a broken record.

[Telarus]

Send you the 2 files I used for the above errors.

[Aaron]

Hi Telarus,

Thanks for the files. PhotoShop was padding the end of the data section with zeros, so I've modified the plugin to accept files that have such padding. The updated plugin will be included in the next developmental build, and I'll post back here when it's available.

Thanks again for reporting this bug.

Cheers,
Aaron.

[Aaron]

Hi Telarus,

The updated bitmap plugin has been included with L3DT v2.9 build 11, which is on the downloads page now. Please let me know if you find any problems with it.

Oh yes, and as to inverting the heightfield, this latest build also includes a nice new 'Operations->Heightfield' menu option.

Best regards,
Aaron.