In e.g. darkplaces the waterfalls are opaque, it depends how each one handles it. Some engines fail to load the key if it's not in the progs definition. 

fitzquake-based engines should all support it without mod support 

I started to wonder if there's some modified ID1 progs.dat with alpha added floating around. 

Preach is right, but the sand has shifted. Around the Quoth 2.1 days, every engine required a .alpha field or nothing would happen.

After FitzQuake 0.85, any engine without automatic .alpha support would get users complaining -- and it is universally supported in modern times (qbism, requiem, qrack, fte, etc.)

DarkPlaces has automatic .alpha and has had it not too long after Fitz 0.85, but sometimes DarkPlaces draw is not the same due to fog or skybox or depth sorting or draw order or even lighting.

[One time I thought DarkPlaces was ignoring .alpha -- it wasn't --- magnifying a screenshot showed it was transparent but the draw blended differently with the background and it was hard to notice.] 

Ah yes. Worth a try. 

Do messages from trigger_once and trigger_multiple entities have to have a sound? I'd like to make it silent but the 'sound' value 0 (which is listed as 'silent' in Trenchbroom) still causes the normal beep-boop message sound to play. 

If a message is displayed, I think it's better to leave the beep on: sometimes in the heat of battle a centerprint can go unnoticed, the beep is useful then. 

"sound" ""
maybe? 

The QuakeC looks like this:

void ()
trigger_multiple =
{

if (self.sounds == 1)
precache_noise ("misc/secret.wav");
else if (self.sounds == 2)
precache_noise ("misc/talk.wav");
else if (self.sounds == 3)
precache_noise ("misc/trigger1.wav");

if (!self.wait)
self.wait = 0.2;

...
}

"sounds" "0" // <---- notice this is plural

Would seem to work. 

Unfortunately doesn't work; I made a typo in #18793 and the default included field is actually sounds, with an s at the end. It does list 0 as 'silent' (http://i.imgur.com/knuXpZT.png) but after a bit of fiddling, apparently the sounds field is only for activating the trigger itself- leave the sounds field blank and the trigger will be silent, set it to 1, 2 or 3 and you'll get the respective secret, bleep-boop or mechanical clunk sounds. It's only when you include a message with the trigger that it forces it to play the bleep-boop even when set to silent. 

Might have to edit the QuakeC in order to do such a thing then. 

The talk sound doesn't play if you set a sound on the trigger! So what you can do is leave "sounds" at "0", then explicitly set "noise" "misc/null.wav". That way touching the trigger plays a silent sound, and the talk sound is suppressed.

Note that you will need an entity somewhere in the map that precaches the misc/null.wav sound, like a door or platform with "sounds" "0", otherwise you'll get a error message. 

What's the best way to work around the MAX_PATCHES?

I consistently hit it even though my maps aren't that big or detailed. I know it's related to the lighting quality and the size of the map, but I just wonder how far you can go and what to sacrifice etc. for a larger map to be possible. I'm all about huge and impressive maps, but I also want them to be lit too. 

The default patch size in the original utils is 64 units, try raising it a bit with "-chop 70". This will make the radiosity lighting a bit lower quality.

It should be possible to raise the limit in the light tool, the patches only exist during lighting so it won't affect engine limits. (but the more patches there are, the slower the light tool will be).

#define MAX_PATCHES 65000 // larger will cause 32 bit overflows
I'm not sure what overflows though. 

I use quality 128 for sky and 256 for water.

How would I raise the limit during the light tooling? 

Raising the limit would involve changing that #define and recompiling the light tool (and check if it breaks anything in the tools :). http://github.com/id-software/quake-2-tools

I use quality 128 for sky and 256 for water.
How about regular solid faces? The vanilla tool only seems to have one -chop option for all faces. 

I use the Arghrad. 

ah, ok. So if you're only increasing -chopsky and -chopwarp, try -chop (which will reduce the # of patches created by other types of faces).

Not sure if source code for arghrad is available so raising max_patches may not even be an option? 

Thank you for your insight, though. I guess unless I take some time to come up with a solution myself, I'll be stuck with this for now.

(Also, the 4096^2 size-limit of Quake 2 maps is pretty decent if it wasn't for MAX_PATCHES...) 

I have a serie of secret_doors that depend on health. I want them sealed to a certain stage before I want to give them access.

If I use a trigger_count to activate them all doors open, and that's what I don't want.
I want to keep them secret untill that certain stage, and then they can be used by shooting.

How should I define this? 

that blocks the secret door 

I made an example with a door and button.
When I seal the button off with a func_wall I need to give it the same texture as the button.
Then I can killtarget it so the button comes free.

What if the func_door secret is hidden in the wall in a strange 15 degree angle with another brush forming the door.
There is no place to give space to a func_wall as it betrays the door itself not only by blocking the wall surface.

I know it sounds a bit queer, but i tried different ways. Only logic way seems to add a trigger_once behind the door that opens it, in stead of shooting it in front. (what had to be the secret) 

check this demo and the example map file
http://quaketastic.com/files/demos/test.rar

is this what you wanna achieve? 

What if the func_door secret is hidden in the wall in a strange 15 degree angle with another brush forming the door.
There is no place to give space to a func_wall as it betrays the door itself not only by blocking the wall surface.  

To clarify this is the secret door. It's in a strange angle.

When a door_secret receives the health arg it opens when triggered. That is what I try to preserve.
I can't fill up the front with a func_wall as it blocks the secret.
When I use a trigger_relay the doors open and are no secret anymore.

I tried the rar files, but I have to use 7zip.
Thanks for the feedback.