32bpp - HowTo

[planetmaker]

How can I play with 32bpp?
Currently there is no fully finished baseset, but zBase is close to finished. A more or less maintained list of base sets and NewGRFs along with their download locations can be found in the wiki.
There's work in progress to support these large files also on the online content system.

How can I use the old 32bpp?
Short answer: difficult.
Long answer: OpenTTD 1.2.0 unified the way sprites can be provided to OpenTTD, thus 32bpp graphics now can be supplied via base grf or NewGRFs. The old way to just provide 32bit png files was removed. Due to the difficulty to determine the license for all sprites, no package has been released, but you can use this script on the old png package to transform them into a newgrf - but be sure to fulfill all the licenses, if you consider publishing the result.

How can I create 32bpp sprites?
Most people use blender. There's a couple of good tutorials in the webs.
Not really final specs (rather look at zBase for examples):
Light settings: http://www.tt-forums.net/viewtopic.php?f=36&t=59654
3Dmax templates: http://www.tt-forums.net/viewtopic.php?f=36&t=47654