Surface light shaders

[curt]

I didn't think any of my original light code still existed, but originally I drew a triangle in GL_POINT mode so only the vertices were shown, and 2 of the vertices were underground so not visible. Then I used the triangle 'face' normal to feed into an environment map that controlled the color/intensity of the light based on it's ideal alignment and the relative view angle. This way approach lighting could be brightest when you were flying down the pipe, and much dimmer when you were at a right angle to the runway, and not visible when you looked from behind. Similarly, taxiway lights were most visible from the surface and less visible from above (as if the light had a cap on it shielding some of the light from shining up.) I was under the assumption most of this code went away during the grand plib->OSG migration (all the special runway lighting effects were lost at that time.)

[ot-666]

I wonder where all the extra lights are coming from?
But it looks like you have at least the rwy-stop lights facing in the opposite direction!
What is the name of the airport are you testing this on? I would love to have a look at it with the help of my script to figure out what points really are in the btg file.
But on the airports i've tested since scenery 2.xx i#ve only seen a couple of doubled up light points in the btg. Usually there are 2 on ony position for each direction.

Oliver

[Thorsten]

That's KINS, but I've seen the same thing on TNCM - they seem to be everywhere. So they are _generated_ somewhere in the light setup process - there's no geometry shader running, thus in order to see a point coming out, there needs to be a point coming in.

[Johan G]

I didn't think any of my original light code still existed, but originally I drew a triangle in GL_POINT mode so only the vertices were shown, and 2 of the vertices were underground so not visible. Then I used the triangle 'face' normal to feed into an environment map that controlled the color/intensity of the light based on it's ideal alignment and the relative view angle.

I wonder where all the extra lights are coming from?
But it looks like you have at least the rwy-stop lights facing in the opposite direction!
...
I would love to have a look at it with the help of my script to figure out what points really are in the btg file.
But on the airports i've tested since scenery 2.xx i#ve only seen a couple of doubled up light points in the btg. Usually there are 2 on ony position for each direction.

...they seem to be everywhere. So they are _generated_ somewhere in the light setup process - there's no geometry shader running...

I guess it is deep, deep down in the abyss of the source...

[papillon81]

Hi,

Emilian and me identified the root of the issue and I'll push a fix to SG soon, along with some cleanups.

Chris

[f-ojac]

Excellent! Thanks Chris and Emilian and Thorsten, this will be a really nice update.

[Thorsten]

Emilian and me identified the root of the issue and I'll push a fix to SG soon, along with some cleanups.

Ah, very good Do we want to know the reason? Probably not...

[Zan]

Hi!

I have to chime in now that there is shader support for lights. Because one of the things that annoyed me was the feature curt mentioned that was lost during transition to osg: light direction. All lights in the c++ code have the direction (normal) but it is not binded, I assume due to some issue in the fixed rendering pipeline? Anyways, with shaders the normal should be binded, and it's length could represent the intensity if needed. Thus runway lights would dim when looked from the side and be very bright when straight in front of them etc...

I assume the right place would be the pt_lights.cxx function getLightDrawable, where there is a BIND_OFF currnetly for normal? Any opposition to enabling normals?

BTW does rabbit lights or other blinking lights work? I don't remember ever seeing them in operation...

Best regards, Zan

[curt]

Rabbit lights and REIL lights worked in the original light implementation and I believe survived the OSG migration. However, I think there might be an issue with intensity/size of the flash which can make these very hard to actually see.