Hi Melchior,
that was a good thread for me :-)
I've come to a good result finally. Now I have a Space Needle which lights
on when sun-angle-rad > 1.57 (dusk) and switches off when sun-angle-rad <
1.57 (during the day). And it does it gradually.
I have another simple question anyway. Do I brake something if I set
emission values higher then 1 or lessere then 0 for red,green and blue? It
works to me without problem but I don't like non compliant hacks if it may
be standardized by doing it in a good way.
My current solution is:
<animation>
<type>material</type>
<object-name>pCylinder1_group5.0</object-name>
<emission>
<red>5.56</red>
<green>0.0</green>
<blue>0.0</blue>
<offset>-8.72</offset>
<factor-prop>/sim/time/sun-angle-rad</factor-prop>
</emission>
</animation>
I got those numbers by building a simple math function for Emission.
Let's say:
sun-angle-rad is x
emission is f(x)
I want the emission to be a linear function of x so that emission is a
positive value between 0 and 1 when the sun goes down the horizon.
Then the function describing the emission variation is:
f(x) = x * red + offset
I want:
f(1.57) = 0 (no emission when sun is still on the horizon)
f(1.75) = 1 (full red emission when sun is a few degree under the horizon)
Solving the math problem I get
red = 5.56
offset = -8.72
Now I come to my previous question.
By using such values I get
f(x) > 1 when x > 1.75
f(x) < 0 when x < 1.57
Are those values acceptable to flightgear? Even if it makes no sense to have
the red component of the emission color >1 or <0 (which are max and min
value)?
Roberto
--
Telefonieren Sie schon oder sparen Sie noch?
NEU: GMX Phone_Flat http://www.gmx.net/de/go/telefonie
-------------------------------------------------------
This SF.Net email is sponsored by xPML, a groundbreaking scripting language
that extends applications into web and mobile media. Attend the live webcast
and join the prime developer group breaking into this new coding territory!
http://sel.as-us.falkag.net/sel?cmd=lnk&kid=110944&bid=241720&dat=121642
_______________________________________________
Flightgear-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/flightgear-devel
