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new light parameters

Posted: Fri Feb 10, 2017 10:15 am
by tonaz
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?

Re: new light parameters

Posted: Wed Feb 15, 2017 1:40 pm
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.


Re: new light parameters

Posted: Wed Feb 15, 2017 4:00 pm
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.


Re: new light parameters

Posted: Thu Feb 16, 2017 2:21 am
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.

Re: new light parameters

Posted: Thu Feb 16, 2017 3:56 am
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.