Shader requests

Please post your shader requests here, so that other people can more easily track what's going on, hopefully avoiding duplicate efforts.

Currently work in progress

Water shader by gral (11/2010)

Please see: http://flightgear.org/forums/viewtopic.php?f=47&t=938

Open shader requests

Flags

is it possible to simulate the fluttering of flags in the wind using a shader? I'd like to place some flags in the scenery for our FSWeekend presentation showing the logo of our sponsor. But attaching a flat surface to a a flagpole looks just to cheap.

See: http://flightgear.org/forums/viewtopic.php?f=47&t=9789

Contaminated runways and taxiways (10/2010)

Ok I have no idea if this is possible, but this idea just came up in my mind: wouldn't it be very cool to apply this shader (actually a similar version of it) to runways and taxiways when it's raining? I know there's not much sunshine when it's raining, but I mean just the light-reflecting idea.

And you could get the visual effect of a wet runway or snow based on weather settings. (http://flightgear.org/forums/viewtopic.php?f=6&t=7383&p=70239#p70254)

To clearify the aspect/feature override part mentioned above here's a different use case I have in mind. 
In a scene where it is raining you typically would want to show all material as being wet. 
This can be implemented at several levels of realism. For a quick start I would increase specular reflection 
and maybe darken diffuse in the top level StateSet. The darkening of materials could be made different for 
several materials in the scene simply by setting a different uniform darkening value. Some objects in the scene 
might implement wetness with a specular cubemap. In case of a road it might even contain puddles and use a planar
reflection of the scene. All these shader pieces implement the aspect "wetness" in different ways, where higher 
fidelity implementations lower in the scene tree override the default implementation in the top level stateset. 
And in case you want to disable "wetness" for the whole scene it should be possible to do so at the top level 
stateset similar to how we are used to disable texturing, lighting etc. [1]

See: http://flightgear.org/forums/viewtopic.php?f=47&t=9386&start=120#p1005044

Runway skid marks

It would be interesting to see if and how this mechanism could possibly be used to dynamically place skid marks on runways at runtime, so that landing aircraft can cause their own, new skid marks during touchdown.

See:

• http://flightgear.org/forums/viewtopic.php?f=5&t=2258&hilit=skid+marks&start=15#p30741
• http://flightgear.org/forums/viewtopic.php?f=6&t=7383&p=70239

Precipitation effects for cockpit windows

Something like this could be very useful for my idea to get a decent rain / snow / ice effect to the cockpit glass with working wipers by simply changing the textures of an overlaying model.

See: http://flightgear.org/forums/viewtopic.php?f=6&t=7383&p=70239

Ideas

sky / atmosphere scattering

has implication on other shaders, and as far as I know, the sky dome can't have effects for the moment [2]

other material types

not all the world should have the "plastic" look of the OpenGL default shading equation ). Crops should have a fur-like lighting response. A first step has already occurred in the reflection shader that should have a metallic look. Research Cook-Torrance (should tell something to blender users) and Fresnel if you want references. First step here : http://wiki.gamedev.net/index.php/D3DBook:Lighting . Oren-Nayar should be perfect for seat fabric. [3]

geometry shader for transforming to billboarded trees

geometry shader to transform points into huge number of billboarded trees (a la Outerra). The code should be modified to generate the set of points following the terrain in the first place, but something similar already exists to create night point lights. [4]

procedural runway markings

set on top a dumb concrete/asphalt/whatever texture/material

post-processing effects

(glow, motion blur, depth of field ) We already have redout/blackout, but could be enhanced by having a circular fading shape (you know when your field of view begins to shrink and you are not able to see on your sides) instead of a constant one [5]