Spinning lights got my head spinning

[JVitale]

I'll forward your question to Dave Jerrard and see what he says...be right back with his answer

[ninjaman]

Wow! Most generous of you!
:bounce: :thumbsup:

Ninjaman

[JVitale]

here's the response from Dave

It sounds like he's making the lights too wide. He could try adding a second light, and halving the values of them. Put the second light on the same null but in a different location, like about 90-120 degress around the nmull from the first light, and about half the distance from the null. This will fill in the gaps a bit without taking as long at going up another AA setting.
Make sure Adaptive Sampling is turned off. Motion blur should be set to 50%, and the null should be spinning from 0 to 720 degrees from frame 0 to frame 1. In 8, set the pre and post behaviours for the null to linear (in the GE) as well as the incoming curve type (linear, not TCB). This should work.

[gerardo]

I just wanted to add, if you want to optimize the scene according to the quality of used Antialiasing, the rotation angle of the spinning object, depends of the lights number (or lights columns) that conform the rig. Commonly and for reasons of facilitating the understanding of the trick principle, is said that this light should rotate 720 degrees, theoretically is this way, but in the practice if we did it, we would repeat the first passing in the same place of the last one, wasting a passing that could eliminate the bands effect. (This that I am saying is a rig refinement and as I repeat is something obviated to not complicating the understanding of how work the trick)
To know the exact angle of lights rotation, you can use this formula (of Dug Stanat):

720 * (#OF AA SAMPLES - 1) / (#OF AA SAMPLES).

720 considering the motion blur is at 50% and 360 if is to 100%.

Example:
For Enhanced Medium Antialiasing (Motion Blur Dithered) we have 9 passes (Medium) but as Motion Blur is Dithered we count 18 passes, then the formula would be this way:

720 x (18-1)/18 = 720 x (17/18) = 720 x 0.9444444444444 = 680

Then for a single light we should rotate the spin object 680 degrees and not 720 as conventionally is said. If we say, you have 12 columns of lights (or 12 lights around the objects) you should divide 720 / 12 = 60, then in the formula we use 60 instead 720.

I like to think of the spinning lights as if they were paint brushes, with which you can paint shadows or to color the difuse of your objects. From the moment in that you visualize it in this way, you realize that the trick is not limited to rotate the lights, but to move them (not necessarily in a lineal way), o to change its color or its size to achieve any wanted effect.
About the stretched spotlights, this is due to these are parented at the spin_object, and if this is stretched, the lights will follow it; however this doesn't change the way in which the spotlights illuminates (the cone will always be circular).
A while ago I made these images:

http://www.geocities.com/gerardstrada/testcath2.txt
http://www.geocities.com/gerardstrada/testroom.txt

They are of this thread:
http://www.cgtalk.com/showthread.php?t=144132&page=1
http://www.cgtalk.com/showthread.php?p=1142322#post1142322

Although they aren´t fotorrealistic, I made them to demonstrate the use of Innercaster (of Ekki) in interiors, one of the most complicated aspects (at least for me) of achieving with the spinning lights trick; I hope to have time to designing a rig especially to solve the problems in interiors, however this tool (Innercaster) solves most of problems related with interiors. If you understand their operation principle, you can make some adjustments to adapt it to more complex scenes. I can´t share the Cathedral files since objects don't pertain me, but I can do it with the other scene (the objects come with LW), hope this help you :)

InnercasterTest (http://www.geocities.com/gerardstrada/Spinningtest.zip)

Besides the Jerrard Set up and Overcaster of Eki, I recommend extensively The Great Texture Area Light Hack (TGTALH) of Court Jester and the Super Spinner of Dug Stanat.

Greetings,


Gerardo

[Carm3D]

I made a spinning light rig too if you want to check it out..

Link (http://vbulletin.newtek.com/showthread.php?s=&threadid=19705)

Enjoy

[ninjaman]

Lightwavers are the kindest people! Thanks y´all for your assistance! I´l´retreat back into my chamber and try out your advice - and a big thanks for the scenes! :thumbsup:

Regards

Johan Grönwall

[nikfaulkner]

wow thanks guys,

i've just tried opening gerardo's innercaster test scene and it's looking for a couple of objects that aren't there. anybody got any ideas what they are? it looks like something to do with overcaster.

anychance we can have tham included in the zip gerardo? i'm sure there is no copyright
issue as eki has his "nagware" version of the software free for download.

nik

[gerardo]

C´mon man! install and test the free version of this excellent plug-in: :)

http://www.kolumbus.fi/erkki.halkka/plugpak/

Greetings,



Gerardo

[nikfaulkner]

hi gerado,


i have already installed the free version, it still comes up with "missing object" errors when i load your seen.

it's a shame because i really liked the quality of light in your renders and i wanted to see how you set it up with innercaster.

[gerardo]

Oh! well, that is weird; I used Overcaster 3 for that image (I think version 6 is the last) however most of the objects have the same names in any version; in any way, here I include those objects :) :

InnercasterTest (http://www.geocities.com/gerardstrada/Spinningtest.zip)


Gerardo

[nikfaulkner]

many many thanks for your patience gerado ;)


got there in the end.

n

[gerardo]

:thumbsup:

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