High resolution images re-exported from old Widelands models
None of the original work is by me. All Blender models and some of the Blender Python scripts are from the Widelands Media repository on Launchpad. All image files are derived works of the Blender models.
I am to blame however for all the ugly shell and AWK scripts. I'll try to redo them in Python eventually, but that's no guarantee that they will be any less ugly.
I include the .blend models to show which version I used to render the
images. Some of them are re-saved with minor adjustments. I tried to indicate
that in the filenames. Some models have an accompanying .info file (plain
text), where I put some notes and reminders on what non-default settings I
used for rendering, or what I had to tweak.
I first try to render all models in Blender 2.79 (on Debian buster).
Blender 2.8+ dropped support for the blender_internal rendering engine, so all textures need converting, and all lights give very different results than old Blender versions, both with Eevee and with Cycles. Fixing this is way beyond my (non-existing) knowledge of Blender.
Some models are incompatible even with 2.79. The problems I saw so far:
- particle effects: this sometimes results in glowing volume regions
- displaced geometry
- weird differences in animations
Fortunately Blender has an archive of all old releases here. I found it easiest to use the w.ndows builds in wine. It even works from the console (no X running) with environment variables, e.g.:
SCALE=7 wine /path/to/blender.exe -b building.blend -P render_settings_b249.py -o building -f 1
(However Blender 2.49- didn't load scripts from other directories, like
-P ../script.py, not even the official Debian build in a squeeze chroot.)
As opposed to wl_create_spritesheet, my scaling scripts keep the cropping
of all the scaled mipmaps in sync, and always leave an empty border of
1 pixel at the lowest scale to prevent bleeding over of scaling artifacts.
(EXAMPLE SCREENSHOT NEEDED HERE)
I have found that using more columns than rows of the animation steps improves PNG compression by a lot. (EXAMPLE SIZE COMPARISON NEEDED HERE)
I try to use filters that cause minimal blurring. I have found that it gives better results to use antialiasing in Blender too for creating the initial high resolution rendered images. This could probably be disabled if I used at least 12x scaled "originals" (3x scale, ie. 9x oversampling at the max in-game scale of 4), but Blender has more information internally, and uses higher quality sampling. See: https://docs.blender.org/manual/ja/2.79/render/blender_render/settings/antialiasing.html
Now I aim for about 6x (1.5x 4), so I use 1000x1000 pixels for big buildings, 800x800 for medium and 600x600 for small. I expect that the original 400x400 will be fine for workers and animals.
I use the Mitchell-Netravali filter in Blender (see above link for a demonstration of various filters) when I can, but I couldn't figure out how to choose it in 2.49- from Python. It's there in the dialog, but the API reference doesn't mention it, and I can't see console output like in 2.79. Any help would be kindly appreciated.
For the in-game mipmap scales I use the Catmull-Rom (catrom) filter in
GraphicsMagick, to minimise further blurring. The resulting images at scale
1 are slightly more blurred than the old ones, but the old ones sometimes
have aliasing issues or stepped edges. Scales 2 and 4 are nice, sharp and
still antialiased with this process. (Scale 0.5 looks good too, but that's
so small that almost anything goes for it.)