Birds

[wkitty42]

hahahahahaha! the ufo doesn't crash, though

[Thorsten]

i'm still looking for my first siting of the birds... are there any notable triggers?

Technically the bird swarms are quads put into the scenery by the random objects code, which are then textured using a shader effect.

So, to see birds, you technically need to:

* have a recent FG with a working random objects code (there was a bugfix just a few days ago, even a week-old binary will not work)
* have random objects on
* run ALS
* fly in a region where they are defined

(Just south-west of Barcelona airport at the river delta is a good place - but it's of course the whole landclass).

They're low - some 100-200 m above ground. They're difficult to spot against bright background, but in the morning hours usually appear bright against the dark ocean. And they're small - so you need to get close to resolve them as birds, from the distance they look like dancing sparks or so.

[someguy]

So, to see birds, you technically need to:

* have a recent FG with a working random objects code (there was a bugfix just a few days ago, even a week-old binary will not work)

Ah. I guess I'll have to wait until the Mac nightly build issue is resolved.

[wkitty42]

they must be skittish of my UFO but i'll keep trying

[wlbragg]

The dawn/dusk picture makes those birds look a lot like Geese. Any chance we might see a line or two of Geese show up in the future?



canadiangeese1
canadiangeese2
canadiangeese4

[someguy]

"Canadian geese?" Are those the really polite ones that go "Honk, eh?"

[Thorsten]

Yes and no - in theory you need to change the noise function against something that prefers a v-shape, which won't play nice with the perpetual motion illusion automatically... (the v may become broken at times) so it's not trivial to do this. I can point you at the right bits of the code if you want to give it a try.

[wlbragg]

Sure, I'll look at it!

[Thorsten]

If you look into birds-ALS.frag, there's this couple of lines

Code: Select all

float domain_size = 0.05;
float r = length(vertex);

float domain_noise = VoronoiNoise2D(lookup_coords, domain_size, 0.0, 0.0);
domain_noise = domain_noise * (1.0- smoothstep(0.5, 1.0, r));

if (domain_noise < 0.9) {discard;}

They determine whether a cell (that's why we call Voronoi-noise) is empty or bird-filled - if empty we discard the pixel, if bird-filled we use a bird texture vignette (chosen by a technique similar to the trees from a texture strip). Currently the random pattern gets modified by

Code: Select all

(1.0- smoothstep(0.5, 1.0, r))

which makes it fade out at the edges. The key is to rig this piece of code such that it fills cells in a v-shape. I have no good idea offhand what would work best for this - whether to simply tabulate it, or use closest distance of cell center to two lines, or something else. But that's the idea to get the V-shape.

As for geese colors, the effect takes two colors as input and uses the black-white on the bird texture to assign them, so there's limited control even without changing textures.

[J Maverick 16]

Someone will come up with a shotgun pretending to be a birdwatcher
Anyway, really nice addition Thorsten!
Cheers, Mav

[someguy]

Someone will come up with a shotgun pretending to be a birdwatcher

Bombable geese, just what we need.

[Johan G]

Hmm, those specific land classes could be of interest for aircraft developers.

[VicMar]

Nothing like the epic Thorsten is working on, but I've been having SeaGulls flying around seaside objects like Lighthouses for a long time.

As I said, my effort is a simple .xml job, but maybe someone could extrapolate from that without too much usage expense.

Example: https://scenery.flightgear.org/app.php? ... ew&id=4803

Cheers,

Vic

[Hooray]

those are actual models, right ?

[VicMar]

Yes, it's like a cascade.
The sub-models point to the .xml for the place where they are put,
Those .exmls point to sets of SeaGull models which are held with them in the data/Models/Fauna folder (or TerraSync/Models/Fauna).

I set them up like that to facilitate the different frequencies of wing beats and heights and distances. The 'Origin' .xmls dictate the height of the placement.

If anyone wants all the files just ask and I'll make them a download on my Weebly web site.