new light parameters

Discussion related to terrain/scenery design.
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tonaz
Posts: 53
Joined: Fri Jan 16, 2015 12:28 am

new light parameters

Post by tonaz »

Hi,
in Pepar3D v3 i've noticed that there are 2 new paramenters in lights FX files:

Light Coefficients = n1, n2, n3, n4
Light Attenuation Range = n1, n2

As always happens, there is no documentation about these parameters in the SDK manual.
Do anyone knows how this parameters work and what they do?
Thanks!
Kevin Cartrette
Lockheed Martin
Posts: 1111
Joined: Tue Aug 14, 2012 6:47 pm

Re: new light parameters

Post by Kevin Cartrette »

Hey Tonaz,

These values are not documented because they have been depreciated. They were used for controlling attenuation of the light emitted by the effect, similar to older OpenGL and DirectX fixed function params.

The attenuation is linear now without those params and is based on the size of the light.

Thanks,
-Kevin.
Prepar3D Graphics Software Engineer
Larry_R
Posts: 510
Joined: Sat Mar 31, 2012 10:05 pm

Re: new light parameters

Post by Larry_R »

Hi Kevin,
This is very useful information. Could you expand a little more on how this works? I’m wondering if you scale area with distance or linear dimensions with distance or something else. Say at distance x, I see an 8 x 8 pixel light. Say it’s a square for convenience. At 2x, what is the size of the light in pixels? Also, do you change the color (lightness) with distance?

These things would be handy to know because editing individual mipmaps is a useful way of adjusting apparent luminosity vs distance. It might take some of the trial and error out of sizing the light in each mipmap.

Larry
Orbx Developer
Gigabyte GA z270x-ud5 mobo, Intel i7 7700k 4.2GHz, Corsair DDR4 3866 16 gig, Gigabyte Raedon VII, Win 10, Evo 960 NvMe 2TB FSX, P3D v3.4, v4.x, v5.x
tonaz
Posts: 53
Joined: Fri Jan 16, 2015 12:28 am

Re: new light parameters

Post by tonaz »

i dont think it is deprecated, couse changing values makes big difference in light power, fade, attenuation, ecc... while i think it is deprecated to use light size, it does not change nothing, or at least it is me not understandig. that' why we need some more in depth documentation about lighting in any case. would be very appreciated!
however, how can it be deprecared since i noticed those parameters from p3d v3 and above only? in p3d v2 and fsx they do not exist.
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WarpD
Posts: 1469
Joined: Mon Feb 14, 2011 5:29 am

Re: new light parameters

Post by WarpD »

Deprecated means they have ceased any support of the parameters and they will most likely disappear without notice.

Time to not use them.
Ed Wilson
Senior Developer
Mindstar Aviation
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