Cumulonimbus Antagonistic Posting
I discovered tonight that Boom's TRANMAP lumps (precalculated translucency tables) are effectively 256x256 flats, meaning they can be edited in Photoshop, Paint.NET, or any other decent image editor that supports layers. This means that they can be manually created and used for all sorts of cool things that basic translucency can't do. With it I've created Boom-compatible additive blending, grayscaling effects, color inversion, hue-shifting, and all sorts of other useful things. They work perfectly in PrBoom and Eternity, but ZDoom completely ignores the TRANMAP lumps, totally breaking the effects. (I've put in a feature request for this, since it seems most people just use ZDoom for everything regardless of intended port.)
A few examples:
http://sl4.poned.com/screens/tranmap-fx/etrn425.png Hue shift, inversion, and grayscale
http://sl4.poned.com/screens/tranmap-fx/etrn413.png Additive blending
http://sl4.poned.com/screens/tranmap-fx/etrn419.png Inverted midtextures and stuff behind them
http://sl4.poned.com/screens/tranmap-fx/etrn418.png Inverted stuff behind midtextures only
The screenshots were taken in Eternity, but this feature was in Boom itself.
I used http://sl4.poned.com/screens/tranma...ps/TRANS100.bmp as a base, a 0% opacity table.
To create a tranmap, open TRANS100.bmp in your image editor of choice, and create a new layer with those same color bars from TRANS100.bmp in it (just copy and paste, or duplicate the layer). 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 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 that sector tag, with your tranmap lump's name as its middle texture. If you've done it right and you're using a Boom-compatible port that's not ZDoom, it should work.
Here are a few sample tranmaps. They need to be converted to Doom flats in XWE before you can use them:
http://sl4.poned.com/screens/tranma...ps/TRANSB_W.png - Turns everything behind the midtexture into grayscale, without actually making the midtexture itself visible.
http://sl4.poned.com/screens/tranma...ps/TRANSBW2.png - Makes the midtexture and everything behind it grayscale.
http://sl4.poned.com/screens/tranma...ps/TRANSAD2.png - Bright additive blending.
http://sl4.poned.com/screens/tranma...ps/TRANSIN2.png - Inverts the colors of everything behind the midtexture, without displaying the midtexture itself.
http://sl4.poned.com/screens/tranma...ps/TRANSIN3.png - Inverts the colors of the midtexture and everything behind it.
http://sl4.poned.com/screens/tranma...ps/TRANSINV.png - Inverts the midtexture only, but not what's behind it.
essel.spork-chan.net - doom stuff, artwork, and music by esselfortium
Last edited by esselfortium on 09-06-08 at 06:56