Tranmap-FX

Tranmap-FX is a collection of unusual graphical effects, created by modifying the resources that utilize the TRANMAP lump from the Boom source port. It comes along with a example WAD called TRANMAPS.WAD. The package demonstrates various new effects achieved through manipulation of the TRANMAP lump, a 256x256 flat.

It was created on September 6, 2008 in a Doomworld thread titled: "TRANMAP abuse in Boom: additive blending, inversion, grayscale, and more!" by Sarah Mancuso (esselfortium).

Details
Tranmap-FX includes various TRANMAP lumps describing several effects. These are all made from a base file, called. To create a modified TRANMAP, open in your image editor of choice, and create a new layer with those same color bars from  in it (just copy and paste, or duplicate the layer). You will import these in XWE or SLADE as a flat.

Then rotate it 90 degrees counter-clockwise (putting the purples on the right), and set its opacity to the amount of translucency you want. Changing the brightness or coloring of the horizontal bars will affect what's behind the midtexture, and changing the vertical bars in the transparent layer will affect the transparent midtexture itself.

Now import it into your wad with whatever lump name you want, and use the Save As Doom Flat menu item in XWE or SLADE to put it into the correct format.

To use it in a map, tag all the lines you want to make translucent, but do not set special 260 (translucent line) on them. Put a line in a dummy sector somewhere that has special 260 and this sector tag, with your TRANMAP lump's name as its middle texture.

Then to actually use it ingame, make a dummy line somewhere with the translucentline special, give the dummy line a tag, and set its frontside middle texture to the name of your desired tranmap lump. Now, for all the lines you want to use that tranmap on, all you have to do is give them that tag. (No translucentline special is needed on them.)

Demonstrated features
Included in Tranmap-FX is a WAD called. It shows multiple effects achieved by modifying the TRANMAP lump. Demonstrated are the following:
 * Black and white fades/blending
 * Additive blending (of colors, they exhibit transparency and color blending in full dark and fullbright areas. In fullbright, additive blending also takes note of wall textures and blends those aswell)
 * Grayscaling effects
 * Inversion blending. One color inverses in another within the main colors
 * Reversed inversion blending. Pitch black and full whites blend and produce a silhouette effect
 * Color inversion blending. Blue/white blends into the next tile, which blends into the next, producing all colors
 * Hue-shifting

Supported ports
Tranmap-FX generally should be compatible with any Boom-compatible port that supports TRANMAP lumps. It does not run with any based port because these are rendering effects whose concepts vaguely resembles, but done in software. Tested are:
 * PrBoom
 * PrBoom+
 * Eternity
 * ZDoom (Supports partial loading, but does not support all advanced effects)