ALPHA.WAD
---------

This tiny PWAD example demonstrates the special QuickAlpha effect currently
assigned to all 'middle' textures named 'sky1'. This name was chosen because
it is always available in IWADs, and it is (almost) never used on middle textures.

Eventually, this will be changed to a unique name, but it will be left this way
for now due to the difficulty of adding new texture names to PWAD files. This
is currently the simplest solution for demonstrating the effect.

The ALPHA.WAD demo uses QuickAlpha to simulate torchbeams shining down from the
roof onto the floor. The texture is only applied to the 1st (outer) sidedef of
each face in order to avoid slow overprinting & unnecessary buildup. This looks
good here because the torch beams are too thin to get 'inside', and they are
supposed to be volumetric or solid - rather than just 4 flat surfaces joined in
a ring. QuickAlpha could also be used to create glass windows, but this must be
done with care, as it takes much longer to render than a normal wall texture. It's
best to keep these effects out of the player's immediate reach to prevent situations
where the QuickAlpha texture covers a large percentage of the screen (i.e. don't
get too close or the framerate will go through the floor).

Additional effects similar to QuickAlpha are planned for future releases.

To view this PWAD you will need a copy of a Doom IWAD file. Both shareware and
commercial versions of Doom will do for this demo.

Syntax:

	bm.ttp -i doom1.wad -p alpha.wad


Have fun...

Doug.
