Geographic Sun on LuxBlend2.5?

[MaRo]

Do you mind if I make a post on BlenderArtists about this addon?.

Of course not!
Bear in mind though, that the addon is largely the work of other people (with respect to the actual sun calculations), I've only re-packaged it in Blender-2.5 form

Brilliant!
Working fine with latest build from graphicall.

[b.!!]

Erm well..(hi) I'm pretty new to Blender 2.5 and I dunno how to install that py file (seems to be a problem for no one else ?)...The best I've done so far is to save the code indicated in a .py file I named Sun_orientation.py...But after that I just dunno what to do

[MaRo]

Hi,

here's where I have put it in my installation:
blender/2.56/scripts/addons/lamp_geographical_sun.py

and then I have actived it in the user preferences, addons panel, objects section:

user preferences, activate addon

I will then appear in the lamp panel when you select a sun lamp:

Lamp settings

Capture2.PNG (28.74 KiB) Viewed 238 times

Hope it helps.

[b.!!]

Hi Maro,

Thanks a lot for that very clear reply !
I was lost about the name of the add on inside blender and the tab I would find it in. For example, you know for sure that when you install Lux or SLG you will find them in "Render" but how do you know you'll find the Geographical sun in "Object" ?

Thanks again for the nice answer !

[27trowels]

Been waiting for this to be implemented before I attempt to make the switch to blender 2.5. Thanks a lot! Also the installation instructions in this thread were very helpful.

I have a related question which you may be able to help with -- I notice that the year you can select only goes as far back as 1800 does anyone know how hard/ if it is even possible to push this date further back into the past? I think I remember reading that it is based on NASA calculations so I'm guessing it may depend on how far back they go. I am hoping to create some natural light visualisations for reconstructed Roman buildings and would ideally like the lighting to be as real as possible.

Also if anyone could point me in the direction of any literature on how Luxrender implements the geographic sun or any literature on simulating natural light I would be interested in reading anything you can think of.

Cheers

Dan

[b.!!]

Hi guys,

I wanted to show you some strange issues with the geographic sun script. As you can see on the series below (a front orthogonal view, with the blue Z axis and the red X axis...) the sun is shooting night during the day and day during the night. What I mean is that its angle (trigononomectric) should not belong to the 0-180 range during the day like it actually does, but to the 180-360 range and vice versa with the night.

In simple terms, during the day hours the sun should be shooting to the bottom of the image, not to the top and vice versa for the night.



Here a screen taken at 2 PM which is quite odd, since it should be night black according to the geographic sun script...

[dougal2]

I think the timezone adjustment might be wrong. I see you've set -13hrs, which would in effect reverse night/day. Can you test again with a 0 timezone offset?

[b.!!]

Ok It seems I messed it without paying attention, since when I change the location it doesn't change the timezone adjustment...so it should normally stay on 0 right ?

I can't recall when I tweaked it lol...
Thanks anyway it works ok now !

By the way, there is a function the plugin really needs, it's a north parameter, like in sketchup for example : when you click on it it gives you a little compass to tell it where the north is, rather than rotating the whole model and loosing ortho etc...

[dougal2]

North is always +Y

[Abel]

North is always +Y

Ideally, yes!

But I would like to second b.!!'s request. I usually model buildings based on CAD drawings. Typically, those are oriented in such a way that the main walls follow the x and y directions, with the direction being closest to north facing up. However, only rarely are buildings oriented exactly straight in the north-south direction, so typically the north direction is somewhere between -22.5 and +22.5 degrees from the y axis when importing the drawings. Of course one can rotate the building, but then one would always need to use local coordinates instead of global ones. Also when importing additional drawings (facades, sections or other floor plans) that would mean that those have to be rotated at non-straight angles which increases chances of something going wrong or being imprecise.