new light parameters

Discussion related to terrain/scenery design.
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new light parameters

Postby tonaz » Fri Feb 10, 2017 10:15 am

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?

Kevin Cartrette
Lockheed Martin
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Re: new light parameters

Postby Kevin Cartrette » Wed Feb 15, 2017 1:40 pm

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.

Prepar3D Graphics Software Engineer

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Re: new light parameters

Postby Larry_R » Wed Feb 15, 2017 4:00 pm

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.

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

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Re: new light parameters

Postby tonaz » Thu Feb 16, 2017 2:21 am

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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Re: new light parameters

Postby WarpD » Thu Feb 16, 2017 3:56 am

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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