Particle system fog

Greedo

<div class="IPBDescription">Yes, it's possible</div>I've spent the last few hours trying to get this fog just right.  Right about now, I think the only thing that really needs to be changed is probably the sprite.  With the sprite a bit darker, and possibly more consistent in transparency throughout (rather than circular and fading towards the edges) this might be an even sweeter effect.  I don't know the first thing about sprite creation or editing, otherwise I would have made one myself.  Anyways, here's a four picture series showing the progression through the hallway, and I've also included the .rmf and the .bsp.  Please note: the pictures hardly do this any justice at all.

Greedo

It's the fog.  I can't see through the fog.

pielemuis

wow i'm gonna test that baby when i get home!
It would be great if they foudn a work-around for the fog probs.

realityisdead

Looks great Greedo. My only suggestion would be to lower the max alpha on the system, and add a few more particles. That would make it feel a bit more like fog rather than mist. Or maybe you are aiming for the lighter feel.

Anyway, it's a great effect! There sure is a lot of creativity coming from this community. <!--emo&:)--><img src="http://www.natural-selection.org/iB_html/non-cgi/emoticons/smile.gif" border="0" valign="absmiddle" alt=':)'><!--endemo-->

Moleculor

Go to <a href="http://www.valve-erc.com" target="_blank">www.valve-erc.com</a>. Go to the Utilities section. Look under 'Sprites' or something like that. There's a program that will extract sprites to a bmp, and a program that will put a bmp (or series of them, for animations) into a sprite.



<!--EDIT|Moleculor|Mar. 05 2002,02:03-->

Flayra

Nice work Greeds.  This way of creating sprite fog quite a bit more efficient and elegant then the typical (env_sprite) way of doing things.  The really nice thing is that these don't count as entities, so that's significantly less network traffic and overhead.  It also means you can easily tweak the effect in one place.  Also, it allows you to check the "high-detail only" flag, so this effect won't slow down people with slow systems.  I would categorize this effect as essentially non-gameplay altering, so it should be fine.

Oh, one last thing.  You see how the fog doesn't appear immediately?  It can take a few seconds for all the particle data to be sent down to each client at the beginning of the game, this is why you'll sometimes see particle systems be created.  This must be done to avoid sending too much data too quickly and overflowing the player.  The presence of the ready room should prevent particles from appearing in front of you in practice though.

I hope more mappers use this!

CyonPro

Mmmmmm.....tasty!

I can think of one place where I might use this in my map, so your work will not have been in vain, Greedo.

Jedisar

I'd gladly use this in one of my maps..if one of my maps were good enough to actually be worthy of it.

Greedo

I would have lowered the alpha and added particles, except that the ps only works in eighths, so it's already at .125.  Unless this has been changed?  And I think that the drop in fps (I was getting around 40.  So yes, high detail only particle system, but imagine the drop on a lower end machine than my own?) would have really tended to preclude the addition of excess particles.

And I must say that this should probably not be used in any large rooms, except maybe above or below the players.  I don't know how well it would perform there, though.

nrby

i'm assuming the NS fog is volumetric, within a brush based limnit? or is it radius of an entity?

realityisdead

Are you talking about the env_fog, n@rby?

I'm not 100% on the technical details, but it is basically a brush based entity that when walked into creates a simulated volumetric fogging effect. Somewhat similar to halflife's underwater fogging. It's density can be adjusted by determining the "Fog Start" and "Fog End". Last I heard it is probably going to be taken out due to problems with the sprites (it starts and ends too apbruptly too.)

Greedo's fog is done using the particle system.

Merkaba, an official NS mapper, created an awesome fog effect using simple env_sprites.

Moleculor

Nah. (They're working on volumetricizing some stuff, like the flamethrower (that will probably only make it in if they get it to 'volumize&#39<!--emo&;)--><img src="http://www.natural-selection.org/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'><!--endemo--> and (possibly) grenades.

The two fog effects that are possible with HL right now are either sprite based, where you have a bunch of those sprite entities, one every 64 or 128 units or so and very low transparency.

Particle fog can be either stationary or moving, but if it's stationary, it's just the same thing as above, and moving will typically be along the floor only.

The env_fog is a special case. What -it- does, is while you are touching the env_fog (just like a trigger) it draws (only in OpenGL) a fog that starts <X> distance away from you and ends <Y> distance away (the difference between the two values being inversely related to the thickness). Since you can only see the fog where there isn't a wall (since you can't look through walls) you see a nice little fog effect.