Sun animation?

[MaRo]

Hi,

let's say I have a architectural scene, and would like to create an animation using geographic sun. Basically, I would like to have a sunrise, then realistic path in the sky during the day, and then sunset.

I guess it could be done in blender with IPO curve and basically setting the start and stop positions, but the reason I would like to do it based on luxblend settings is that (if I'm not mistaken) it changes the colour (sky turbidity and sun halo?) depending on the coordinates and time of the day/of the year.

Any hint would be greatly appreciated to start in the right direction
I don't know if this requires python scripting, but I would be ready to dig in too.

Thanks!

[jeanphi]

Hi,

The date/time/place only changes the position of the sun, not the turbidity (related to the pollution level or wetness of the air) nor sun halo. The position of the sun makes the color change by itself. The color is however also dependent on the turbidity.

Jeanphi

[MaRo]

Ok, thanks for this precision on the subject! So if I understand well, the color is basically automatically set by the script to simulate the influence on light of the thickness of the atmosphere, depending on the position of the sun in the sky (angular position and variation).

So, I am still looking for hints on how to proceed to prepare the animation frames. I mean, the sun trajectory is not a simple circle as seen from the ground. So how to set up a realistic path?

[jeanphi]

Hi,

The color isn't computed by the script, but by LuxRender itself depending on the sun position and the turbidity (and various other factors). To get a nice animation you should animate the day time.

Jeanphi

[SATtva]

To get a nice animation you should animate the day time.

I.e. sun lamp direction -- nothing else is needed.

[MaRo]

I.e. sun lamp direction -- nothing else is needed.

I'll try fiddling around this during the weekend. Thanks!

[Lord Crc]

I'm no blender guru but could you animate the "time" parameter of the sunsky calculator?

[dougal2]

I don't think you can animate the time parameter directly, but you can use the sun calculator to set the position of the sun and then keyframe it manually.

eg. goto frame 1, set time = 7am, IKEY insert LocRot
goto frame 10, set time = 10am, IKEY insert Loc Rot ... .etc etc...

[SATtva]

Calculator time parameters doesn't have an IPO keying (they can be modified though). The bigger problem is that the whole calculator seems a big bug to me: its geographic positioning of the sun are totally wrong (e.g. it gives sun position just above the horizon at 15:00 in Moscow -- what a hell?!).

[dougal2]

hrm...that probably goes to show just how often people use it
At the time it was implemented I was fairly certain it was correct, and I asked for feedback regarding its accuracy; nobody replied IIRC.