Sunrises (version 1.3 available)

[Michat]

Lets count the lot of thanks thorsten received, lets divided it by number of code lines, posts, answers, reportages and screenies, IRC relays he made.

If my account is true, we are on debt with him. About 1 million of thanks deficit.

Same with all developers, I have no thanks to fill the hole.

All stars that can be observed on FG's are you, the development team.
I feel I standing in front of the cosmos. You scripts code shape the constellations.

Alpha centaury, M80, what is the galaxy your coming from?.

You the talibans of software (taliban means master) very thanks to show me on first person where is the way to the stars.

Hhehehe lol time.

[Thorsten]

Some tweaking to Advanced Weather to give the thunderstorms a more usable framerate - after reducing the cloud density in the surrounding layer and cutting the amount of textures in the smaller Cb clouds by 75%, I end up with a scenario which runs just fine at vsync 60 fps (used to be 15 fps).

So... Cb towers look exceptionally impressive at dusk, since the 10 km altitude difference from top to bottom means that the cloudtop can still be in sunlight whereas the base is already in shader. Here are some Caribbean adventures in thunderstorm conditions:









One problem is that rain textures are currently orphaned once clouds drift in wind. They used to be Nasal moved before complaints about framerate, but then the C++ code moving them which Vivian devised wasn't accepted either, so now there's nothing moving them. I need to discuss this on the mailing list before the next release...

[Thorsten]

Who can spot the new graphical goodie soon to arrive (hint: it's not on the island...)

[Soitanen]

Procedural texturing on water?

[Trez]

Oh my,

that's what allot of us have been waiting for any info for when it will be on git?

[Thorsten]

Procedural texturing on water?

Well, the water shader used to be procedural to begin with (it sums sine waves), but yes - Perlin noise modulation of water color and surface ripples. It is, however, in essence a cheat - it does not know about real depth distribution of the water.

[Thorsten]

Anyone wants... surf?



I've figured out by accident how to get this - it appears the non-upward normal from the terrain is bleeding into the sea if the terrain is steep enough, and this can be used to single out areas of surf. Works only for cliffs, but you can't have everything...

[f-ojac]

Great, thanks a lot again.
Maybe "beach" detection is something achievable? I mean a beach can have a proper landcover type.

[Michat]

1. Procedural water: Have you tried same effects on rivers?

2. I wonder if same kind of effects can be used to express the deep water versus no so deep, around some coast lines shape files. Also the shader, could be used like a sandy button effects. i.e over delta's rivers.

3. About stormy weather, what about to use some flash light in order to represent some kind of action. i.e daylight when lightning, or something like that....

4. Thanks IncrediMan.

[Thorsten]

Maybe "beach" detection is something achievable? I mean a beach can have a proper landcover type.

If we had a beach landclass, we could probably do some interaction with water if the height mesh of the terrain is good. But it often isn't that great, I've tried some strategies alreay.

1. Procedural water: Have you tried same effects on rivers?

Actually, I discovered the surf effect by trying to get fast-running (=steep) rivers to foam a lot more - sadly it looks a lot better on water than on rivers now, but I'll probably deal with that.

2. I wonder if same kind of effects can be used to express the deep water versus no so deep, around some coast lines shape files. Also the shader, could be used like a sandy button effects. i.e over delta's rivers.

No. The effect uses a rather peculiar thing (the fact that the normal is interpolated across triangles means that it's not technically 'up' immediately where the water starts) to tag the coast - and this isn't well controllable.

3. About stormy weather, what about to use some flash light in order to represent some kind of action. i.e daylight when lightning, or something like that....

We used to have a thunderstorm with lightning long ago. I guess in principle this can be done, but it's tricky. i've been toying with Cb clouds at night being illuminated by lightning, but it doesn't have priority.

[f-ojac]

If we had a beach landclass, we could probably do some interaction with water if the height mesh of the terrain is good. But it often isn't that great, I've tried some strategies alreay.

Have you tried cs_sand we have in CLC (try France850 for instance)?

[Thorsten]

It's a very tricky problem because you have so little information in the shader.

Suppose I want to add waves rolling out on the sand. This should happen if (and only if) water is adjacent, it doesn't do to have waves everywhere in a desert - but I don't have adjacency information of landclasses in the shader.

So we need to guess what is beach and what is other sand, perhaps based on absolute altitude, if it's close to zero altitude it is assumed beach, otherwise just sand.

Then we need to know from which direction the waves come - but again, there is no adjacency or directional information in the shader, so we could only use the terrain slope and draw waves coming from zero altitude up to where the sand landclass is, say, 2-3 m altitude.

However, in practice, in most places the terrain mesh way isn't good enough - there are large parts of land which are drawn at exactly zero altitude, so if I try this, substantial parts of the coast suddenly appear flooded. In other parts the land is even lower than the ocean.

So using an ideal mesh and a dedicated 'beach' landclass, one could do something, but with the terrain we have it doesn't look good in many places. It works perhaps 50% of the time, and that's not good enough, the perception keys on the 50% where it doesn't work. I think one would really need to attach vertex attributes which provide the adjacency information - which requires changes to the way we generate and store terrain.

[Thorsten]

Some more work done - the wake shader is now working under ALS



and the rather sharp horizon line seen from high altitude is now blurred dependent on the value of the aloft visibility. I'm also experimenting with adding some noise to the horizon line as well as subtle lightness variations of the horizon fog to make things look a bit more realistic.

[Thorsten]

Some illustration of the new horizon effects:

Morning scene with 120 km visibility from just above the lowest haze layer - pretty sharp horizon:



Same scene with 20 km aloft visibility - the horizon blurs.



Same scene with 120 km visibility, but uneven surface of the haze later - the horizon is blurred in some places, sharply defined in others:



As one increases the altitude above the haze layer, the unevenness gets smaller and the horizon gets back to sharply defined as the geometry from high above dictates. I've been using a 2d noise field where one component is the angle, the second component can then be time, so the structures would slowly but smoothly change as time passes.

[Michat]

Congratulations and thanks for your work.

The horizon effect is pretty cool. I wish to see in Africa were moisture is very elevated, but unfortunately I don't have PC to run FG.

Is a good way to control the effect with time, due that horizon effect changes in the early morning with the first sunrise-hot gradient and makes the oppossite gradient when sunset. I wonder is there is a way to interpolate some kind of variable relative to the position of the sun, in that way that horizon effects will not the same for East and West.



Have a good summer.