Hopefully not TOO stupid a question...

[Inscrutable]

...though it probably is!

Basically I'm looking for a straight forward definition of what exactly the GI setting does.  If anyone has any examples of the same image rendered with different GI settings that would be helpful too.

I've been plugging away with TG2 since January, producing lots of picture that I'm quite happy with, but as is often the case with these things, there are a few little things that I never really bothered to develop an understanding of.  GI is one of these - my tendency has been just to increase the settigns by 1 or 2 above the default on the (admittedly flawed) assumption that more = better.  However, I've recently been getting the "red death" bug and, coupled with the fact that my renders are regularly taking 20+ hours, I think it's time for me to look at GI a little more closely!

Hopefully someone out there can shed some light on this for me (honestly no pun intended!)

Inscrutable

[Will]

Hi there!
            Here is a link to anouther GI question with an awnser, also I will try to find the thread with the pics for you.

http://forums.planetside.co.uk/index.php?topic=945.0

Regards,

Will

[rcallicotte]

The GI (Global Illumination) is useful, but can be overkill quite easily as I understand it.  Especially in certain situations, it is better to just put zero for the GI settings to keep the red out.  I think this will eventually be fixed.  Otherwise, I've been told going over 2 is hardly necessary for most scenes.

If you can't find a post on a subject by doing a search, go ahead and ask.  It would be stupid not to.   

...though it probably is!

Basically I'm looking for a straight forward definition of what exactly the GI setting does.  If anyone has any examples of the same image rendered with different GI settings that would be helpful too.

I've been plugging away with TG2 since January, producing lots of picture that I'm quite happy with, but as is often the case with these things, there are a few little things that I never really bothered to develop an understanding of.  GI is one of these - my tendency has been just to increase the settigns by 1 or 2 above the default on the (admittedly flawed) assumption that more = better.  However, I've recently been getting the "red death" bug and, coupled with the fact that my renders are regularly taking 20+ hours, I think it's time for me to look at GI a little more closely!

Hopefully someone out there can shed some light on this for me (honestly no pun intended!)

Inscrutable

[Harvey Birdman]

What's this? Someone threatening my dominance of the stupid questions?

[Oshyan]

Global Illumination is a fairly common rendering technique these days and although TG2's GI system works a bit differently and is more tuned to the needs of large-scale landscape scenes, the general principle is the same and the results often similar. Thus it can be explained with the wide range of very good existing literature on the subject. This is a good start, with illustrated examples of the difference with GI off and on: http://en.wikipedia.org/wiki/Global_illumination In short Global Illumination attempts to simulate the

The detail settings for GI available in TG2 are explained in this thread: http://forums.planetside.co.uk/index.php?topic=874.msg8495#msg8495 Suggested detail levels are covered in the thread Will linked to above, in my post at the end.

If you have any further questions not answered in those threads feel free to ask. There are no stupid questions.

- Oshyan

[Inscrutable]

Thanks everyone.  I continue to be amazed by just how responsive and helpful forum members here are.

For info, I had set off a large scale render yesterday morning (before posting the original message in this thread).  Left it over night and this morning I accidentally managed to crash my computer with the loss of around 24 hours worth of rendering.  The crash was definitely my fault and nothing to do with any TG2 bug so don't worry.  I've now restarted the render having set the GI settings to 0, hopefully the render shouldn't take as long this time (they were both set to 3 originally).

Once again, thanks for all of your advice.

[rcallicotte]

You might even try 1 in each.  A little longer, but more detail.

[Oshyan]

GI settings of 0 will turn off GI altogether. If you do that it's advised that you use an alternate method to light up the shadows realistically, such as the fill light setup I posted here: http://forums.planetside.co.uk/index.php?topic=580.0

GI settings of 1 are generally find and although it will impact render time of course, the performance loss is not bad and the results can be great. This image by Luc Bianco was made with GI of 1:1 I believe, and the lower part of the canyon is entirely lit by indirect lighting: http://www.planetside.co.uk/gallery/v/tg2gallery/7-canyon14.jpg.html

- Oshyan