A Brief History of Twister
Twister is a program that generates a displacement that would usually take an extremely long time, or just be impossible to do in Hammer.
v1 VMF generation
Twister started out as a program with the single purpose of generating a displacement that twisted 90 degrees along the central axis, to give the result of a lookalike of the twisted corridor from 'The Legend of Zelda: Ocarina of Time'.
After this was achieved, I was encouraged to put in more options and release the program. Curved ramp generation was added and the first version was released on December 29, 2006. Two days later, the option to change displacement power was added, and the nasty text files used to generate the text files were embedded.
The first few days of 2007 resulted in more features for twist and curve generation, and a preview option for curve. (Please note, the preview option is just a gimmick, and i have no intention at all to add any kind of 3D preview.)
Also added were noise and corner generation, where a problem was found.
v2 VMF generation
The corner generation called for a displacement on its side, and my current, inefficient VMF generation 'algorithm', which used a series of 8 or so embedded text files to make the VMF, was insufficient.
I wrote a new, better, algorithm, which, even though it still uses some text files, uses less, and can use all different sides for the displacement, not just the top.
Unfortunately, I didn't convert all the tabs to v2 generation, just the ones that needed it (only corner at this point).
A few weeks after, domes, cones, and circles were all implemented, all with v1 VMF generation.
v2.5 VMF generation
v2.5 is the last version of generation to be used in Twister v0.2. v2.5 adds support for multiple displacements to be generated at once. It is a modified version of v2, hence v2.5. At the moment, it is only used for heightmap generation.
v3 VMF generation
This version of VMF generation was released with Twister v0.3 on Feburary 12th, 2007. v3 generation, while being about twice as long as v2 generation, it replaces v1 and v2 with 2 lines of code, compared to 36.
v3 also negates the need for embedded text files. The only algorithm in Twister 3 not to use v3 was Heightmaps.
v5 VMF generation
Yes, I skipped a number. But Twister 5 is too big of an update to be just one number, so it got two. Twister 5 was rewritten from the ground up in C# (instead of Visual Basic like previous versions). It introduced brushwork and Goldsource 'displacement' generation, as well as sphere displacement generation.
The algorithm for Twister 5 is significantly improved on previous versions, and even though it added three times the generation functionality, it acutally uses less code than the last build of Twister 3. All modes use this method of generation.