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Global Illumination and rendering issue
Posted: 02 March 2012 02:22 PM   [ Ignore ]  
Total Posts:  9
Joined  2011-09-28

Hello,
i just started a new project. Basiccaly i have to recreate a studio enveironmnet wich is gonna be very stylized.
I created my scene.
-a studio
-a logo in the middle
-few light(left, right, overhead)
-some video production 3d objects i bought online
-and some graphic elements.
I rendered a frame using AO, GI and Antialias 2.
I really like the look of it.
The only problem is that to render a frame it takes 10 minutes.
my prjects is gonna be 30 second long and normally i work always in very tight deadlines.
Plus I hear global animation creates flickering when you animate objects.
Any suggestions of alternative way of illuminate the scene and make the render faster and at the same time achieve a great look?
Cheers Marsio

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Posted: 02 March 2012 02:50 PM   [ Ignore ]   [ # 1 ]  
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I can’t make any comments on a scene without seeing it, especially when it comes to something complex or adding in something like GI.
If you are using the standard GI then your settings have to be adjust for your scene specifically…there is no golden rule.

Render optimization is a pretty huge field in it’s own right and you also need to really consider if the benefit outweighs the result.
This is very true for GI…how much of the effect of your GI could be recreated with lighting.
What other considerations do you need to make for the GI?
Are there transparent objects?
Do some objects need the same number of samples as others?
Are objects animated or just the camera?
Do you need details in the GI or general light info?

As for flickering, it is avoidable with standard GI but generally at the expense of render time.
There is the option of using QMC or II, both of these options will produce flicker free results but can be slower.

Again, there are so many factors that go into the speed of a render it is impossible to say exactly what must change.

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Posted: 02 March 2012 02:59 PM   [ Ignore ]   [ # 2 ]  
Total Posts:  9
Joined  2011-09-28

Hello I just tryed to attach a scene but when i c;lick “submit post” it dont works

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Posted: 02 March 2012 03:33 PM   [ Ignore ]   [ # 3 ]  
Total Posts:  9
Joined  2011-09-28

By the way i just did a test rendr on the picture viewer with and without Gi and the result is
6.50 min with Gi
6.05 minutes without Gi
So i dont think is the question of Gi.
And if I render with Gi on but with antialias setted to geometry the render time beame 1.20 min
and if IO set antialias to Best 1/1 it takes 2 minutes to render a rame wich is not bad

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Posted: 02 March 2012 03:52 PM   [ Ignore ]   [ # 4 ]  
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I’ll look into an option.
In the mean time What are your computer specs?
I could give you times…but they may not matter if my comp is faster or slower.

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Posted: 02 March 2012 03:57 PM   [ Ignore ]   [ # 5 ]  
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Ah, then you are looking at issues of AA rather than GI.
In general the AA should still be pretty fast, but it depends on what you are rendering again.
If there is a loft of surface detail, or contrast changes across a surface more time needs to be spent on these ares to make sure that you are seeing the correct result.

Areas of low contrast/low detail generally need less AA.
You can try adjusting the threshold value for the AA. default is 10%...raise this values and you get faster renders, but it may lead to jagged edges or boiling/noisy textures. lowering this value will usually result in clean anti-aliasing but slower renders.

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Posted: 02 March 2012 04:09 PM   [ Ignore ]   [ # 6 ]  
Total Posts:  9
Joined  2011-09-28

Yes I toght it was Gi issue but then i realized it is more an issue of Anitaliasing then GI.
Is a shame i cant upload a scene so you could have a look to it.
But lets say at moment 2min of render for each frame to achieve the result i was looking for is not bad

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