Simulating atmospheric perspective

[Springheel]

What does the above do?

[grayman]

Looks like it creates a foglight, attaches it to the player, gives it a light value and an opaque distance of 250. If it basically works, you'll want to bump up the opaque distance.

[SteveL]

Is the $ throughout a typo? Or does it relate somehow to the (unused?) entity variable declared on line 3?

Edited January 26, 2014 by SteveL

[grayman]

Is the $ throughout a typo? Or does it relate somehow to the (unused?) entity variable declared on line 3?

 

Yes. The $ should be removed. Should just be 'foglight'.

[Springheel]

Looks like it creates a foglight, attaches it to the player, gives it a light value and an opaque distance of 250. If it basically works, you'll want to bump up the opaque distance.

 

I'm not sure what would make it work differently than a regular foglight; unless the "fogs/blendlight" shader does something.

 

How do I bind a custom light to the player?

[grayman]

If the custom light already exists, I assume it's:

 

$<NameOfLight>.bindPosition( $player1 );

[Springheel]

Hmm, I tried that script xcen, but I didn't really notice it doing anything.

[Xcen]

Forgot something important.

 

Fixed and tested.

 

Should be working now.

[Springheel]

Ok, it's definitely doing something now...gigantic shadows are being cast as I move around. But I don't see anything that looks clearly like fog. What exactly is is supposed to do?

 

edit: didn't notice the "replace" comment, will test that...

 

edit: ok, that seems to be working, thanks.

[Bikerdude]

Got a basic map so we can see how its done Springs?

[Springheel]

I'm going to test it right now and if it works then post some pics.

[Springheel]

Well...it's close, but has problems. First, since it's an additive blend, it makes everything lighter, which looks a bit artificial (click image to see animated comparison). Secondly, there is noticable banding as you run around--that might be solvable by smoothing out the light texture, but it already looks pretty smooth to me. Meh, I think I'm going to give up on this for now...it's already taken me all day.

[Diego]

At these small distances the effect should be really small. Also, notice that light plays a role in the formation of this "fog", after all we only see the sky as blue during the day. At night the atmosphere becomes much more transparent.

[Arcturus]

One way of removing banding is adding noise.

[Springheel]

At these small distances the effect should be really small.

 

With regular fog you can make the effect quite subtle. It just looks like the night is a bit hazy, with is ideal. But it has that caulk problem. Using a blendlight might work okay for really thick fog, but it's not so good for the subtle kind. Although with a blend filter you could create a neat effect where things in the distance look pitch black, and the ambient world light only lights up an area in the player's immediate vicinity. That could be useful for horror maps or where you want things to look very dark artistically, without the player being unable to see anything close up.

[rebb]

Regarding the problem you were having with fogged caulk-brushes, maybe you could just apply the portalSky material to them instead because the portalSky material itself is also map-sealing.

[Bikerdude]

Well...it's close, but has problems.

And one of those is the way the top edge of the building contrast against the sky, I dont beleive TDS does that.

[Springheel]

Regarding the problem you were having with fogged caulk-brushes, maybe you could just apply the portalSky material to them instead because the portalSky material itself is also map-sealing.

 

That would require rebuilding parts of the map, unforunately. Caulk brushes have a huge benefit--they seal the map, but you can still see func_statics through them. So you can put a caulk brush right through the middle of a func_static building, and the entire building will still be visible regardless of what leaf you're in. If you use a portalsky brush, then the building would always look like it's cut in half.

 

What is it about portalsky that allows it to ignore fog, that caulk lacks?

 

And one of those is the way the top edge of the building contrast against the sky, I dont beleive TDS does that.

 

Yes, that's because it's an additive blend. All it can do is make things lighter, so it looks bad against a dark sky.

[RJFerret]

Or vice-versa, could/should PortalSky gain the secret ability Caulk has to reveal func_statics from other leafs? (And where might that tidbit of info be best conveyed to mappers, I don't recall where I stumbled upon it in the past, but wasn't via mainstream sources.)

[Bikerdude]

Yes, that's because it's an additive blend. All it can do is make things lighter, so it looks bad against a dark sky.

I suppose you could put a blend/fog light in the skybox so you don't see the stark divide etc.

[Springheel]

(And where might that tidbit of info be best conveyed to mappers, I don't recall where I stumbled upon it in the past, but wasn't via mainstream sources.)

 

Good question. Maybe in a section on visportals in the wiki?

[rebb]

I sort of got it working in a test-map by essentially just putting a very thin and simple func_static textured with skyPortal with an offset over the areas where the caulk showed white spots.

 

Since func_statics are not cut / overwritten by caulk they are drawing over the "caulked-away" parts of the sky.

Not exactly sure if this might cause z-fighting though if those "sky sheets" are too thin.

 

Seems hacky but yeah.

[Springheel]

Can you explain that more rebb? If the portalsky func_static is in front of the caulk brush, how do the func_statics further behind show through?

[SteveL]

(And where might that tidbit of info be best conveyed to mappers, I don't recall where I stumbled upon it in the past, but wasn't via mainstream sources.)

 

It's well covered in the City Street Visportal Tutorial which is where I learned about it.

[rebb]

Can you explain that more rebb? If the portalsky func_static is in front of the caulk brush, how do the func_statics further behind show through?

 

If you have func_statics that physically intersect the sky then that could potentially be a problem with this approach.

 

Small example-map ( it's very artsy ) in the attachments. It has 2 sides of map with the same setup, but one side uses func_static over the skybox.

 

It's just a fast example, this can probably be done much cleaner, possibly by turning the sky behind the func_static skybrushes into caulk.

sky_fog_caulk.map.txt