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REQ>Sun Position-Time of Day and Geographic Data

Posted: Fri Aug 10, 2007 4:57 pm
by joegiampaoli
I'm not sure if this has been requested before or not, also I think it's more of an exporter thing than indigo core system.

Is there a way to precisely know what my sun position and angle in blender for example could represent an exact time of day and geographical place?

Posted: Fri Aug 10, 2007 11:50 pm
by Kram1032
hum...

hard...

1) north south east west isn't defined - you can't make it 100% accurate
2) at the same time in the same timezone, the sun stands differently, 'cause of the north-south cordinates... (and the season)

you might find sort of a calculator, for that, or simmilar, dunno.
Or if you (or someone else) finds a formula, you can use that, yourself, then. ;)

...definately possible, if you do it correctly

Posted: Fri Aug 10, 2007 11:57 pm
by suvakas
This is implemented in 3ds Max (don't know how acurately Indigo renders it though)

Posted: Fri Aug 10, 2007 11:59 pm
by mrCarnivore
I think that should be part of the 3d-prog or the exporter...

you would have to define GPS coordinates, the exact date and time and the direction where north is in your render (or default that to the poitive x-axis or something else). The rest should be pretty easily calculatable.

Haven't found a formula, though. (Haven't looked for it tbh. :-) )

Posted: Sat Aug 11, 2007 12:02 am
by Caronte
Kram1032 wrote:you can't make it 100% accurate
Wrong.
Several softwares have that (Max, Cinema4D, Terragen, Carrara...) and you can determine the position like in a global map (latitud&longitud).

Posted: Sat Aug 11, 2007 12:03 am
by Kram1032
He asked for blender

Posted: Sat Aug 11, 2007 12:16 am
by Caronte
Kram1032 wrote:He asked for blender
We only need some maths and a coder ;)

Posted: Sat Aug 11, 2007 12:19 am
by Kram1032
yes...
that's what I meant with the rest of my post...
you might find sort of a calculator, for that, or simmilar, dunno.
Or if you (or someone else) finds a formula, you can use that, yourself, then.
:wink:
:wink:

Posted: Sat Aug 11, 2007 12:57 am
by Caronte
Making a quick search on google seems there is enough info to do it, but the coder is more dificult :P

Posted: Sat Aug 11, 2007 2:46 am
by filippo
only for max user ...you can see http://www.indigorenderer.com/joomla/fo ... php?t=1241
this tutorial it is write in italian, but the setting is very easy..
filippo

Posted: Sat Aug 11, 2007 3:31 am
by zsouthboy
Maxwell actually made you do this information to set the sun position (last I used it - might be different now).

Personally, I *don't* see the value in it. Calculate it yourself, if needed.

Posted: Sat Aug 11, 2007 4:20 am
by Headroom
I believe there is a script for Blender that helps you do that.
I remember that I read a post in respect to this on the Blender artists forum, so you may search the forum there for a solution.

For the Radiance lighting analysis software such a solution already exists and I think it is called "gensky". As radiance is open software a skilled programmer (which unfortunately excludes me :( should be able to interpret that source code and replicate something similar for Blender or Indigo. That however really should not be part of Indigo as a render engine.

Posted: Sat Aug 11, 2007 4:21 am
by Headroom
I forgot to add the link to the Radiance website:

http://radsite.lbl.gov/

Posted: Sat Aug 11, 2007 5:17 am
by crsrma
Something like this has been in Lightwave, for god knows how long... It'd be sweet if it were part of Blender itself. I suggest making a feature request on the blender.org site. ;)

Posted: Sat Aug 11, 2007 6:07 am
by neepneep
http://www.stellarium.org/

Maybe Ono can copy and paste some of this into Indigo? :D :? :D

edit: I just noticed that they also have an API under development :twisted: hmmm?