mental ray stories -Final Gathering- - Page 3

# 31 09-12-2002 , 02:52 PM

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Here we go. This rendering took about 3 hours time on my computer.

Default Production mode, with 1000 finalgather rays.
MinRad = 1 and MaxRad = 1

RESULT:
Looks good, although it is still grainy, but much better than the preview rendering.

Looking at the columns, the sampling can be improved by setting min samples to 1 or higher (warning: higher sampling takes much longer time to render if I recall correctly).

Last edited by undseth; 09-12-2002 at 03:07 PM.

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# 32 09-12-2002 , 03:42 PM

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hmmm I decreased the minrad to 0.1 with maxrad at 1, but it looks like it is more grainy than the minrad and maxrad 1 solution earlier.

Of course, the finalgather rays were never set higher than 200 in the previewfinalgather mode.

This lastest rendering took 35 minutes time to process.

I want to go back to my first solution with min- maxrad at 1 and 10, to see what the limits are when rendering with very high amount of finalgather rays.

I guess it would be nice to render out with these ray counts;
x4 4000 finalgather rays
x16 16000 finalgather rays
...just to see if the grainyness will go smooth out.

But I have just rented the movie Scorpion King on dvd, so I'll do the rendering later this evening. user added image

Last edited by undseth; 09-12-2002 at 03:51 PM.

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# 33 09-12-2002 , 05:38 PM

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just a suggestion, but maybe you can key the settings and let it batch render a whole series when you sleep.

anybody know what the difference between normal reflection and hdri reflection is?

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# 34 09-12-2002 , 05:53 PM

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I intend to do a render tonight while I sleep, to get that fantastic render quality. user added image

I dont know much about hdri images, but I think such a file has a dynamic content that adjusts itself according to over- and under-exposure in renderings. I think hdri images keeps up the subtle contrasts when you say flood your scene with light.

I do not support Bush! Nor Saddam! Long live UN!

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# 35 09-12-2002 , 08:54 PM

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RESULT:
This is quite nice I think. I'm not sure how a high min- and max-radius affect the rendering of smaller objects, but I guess cranking up the finalgather rays alone gives some very decent results.

This rendering had minrad at 1 and maxrad at 10.
Finalgather rays was set to 4000.

I'll do a 16000 ray render in my next post.

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# 36 09-12-2002 , 10:50 PM

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i wonder what you will be able to do if you change the lighting to something more complex then a sphere, or if you let the sphere lit by global illumination and then make the final gather.

amazing stuff already - but one question:
i know you have some knowledge about architecture, did you learn lighting there as well? or do you learn it with trial and error now ??

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# 37 10-12-2002 , 01:22 AM

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now put all together and write a tutorial. Very nice iniciative. Keep going.

Rodrigo Soares
www.r3dimensional.com

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# 38 10-12-2002 , 07:35 AM

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BabyDuck:
We learned something about light, by painting exercises. About sunlight and and the diffuse bluish light from the sky.

Global Illumination works with FinalGather, there may be a way to combine both, in a time saving manner. I'll try that later.

Oh, and started a renderjob before I got to sleep. I set the finalgather rays to 20000, and it only got to about 17% before I decided to abort the render. Seems like I should lower the ray count a bit user added image

Rodi:
I want to make some summarizing out of all this. Just a little more experimentation and I'll get a little more wiser about all this.

I do not support Bush! Nor Saddam! Long live UN!

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# 39 10-12-2002 , 11:17 AM

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Oh, I just remembered that the minrad and maxrad setting can be automated. Simply set them to "0".

This pic is not the 16000 ray setting, but a 4000 with min- maxrad settings to "0".

Um, it looks nice, and renders a bit faster I think. Now I'm puzzled user added image

.

RESULT:
The shading is different here. The diffuse is more smoothed out! Can you see it, compared to the former pic with 4000 finalgather rays?

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# 40 10-12-2002 , 12:53 PM

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This is another rendering with automated min-maxrad settings. Which was set to "0" on both min and max.

Finalgather rays =16000

RESULT:
The small shadows beneath the big slabs in the center, has dissappeared with the automated min-maxrad function.

So I guess these are the things that has to be taken into concideration when fiddling with a speedy final gather solution.

hmmm! I wonder what Maya put into the min-maxrad here!?!

Although I raised the final gather rays from 4000 to 16000, I cannot see ANY change in quality.

Well I'll try the 16000 ray count on the earlier solution, with min- maxrad at 1 and 10.

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# 41 10-12-2002 , 03:46 PM

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Ah, finally the 16000 ray render. This was with the PreviewFinalGather quality, with min- maxrad at 1 and 10 respectfully.

Now I like this pic, it doesnt have good sampling, but it tells me something about the settings I have worked with.

I have still the pleasure to render out a fantastic rendering with the production mode default values, with finalgather rays at 4000+, but it is no rush for me.

RESULT:
Well, the small but important shadows reappeared in this rendering, when the min-maxrad was set to other than "0".

I have been thinking, that I should also try to figure out what min- max rad is necessary for making the smaller shadows appear.

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# 42 10-12-2002 , 04:05 PM

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I now want to figure out what "happens" when one of the two radius settings is set to "0" and the other to a 0+ value.

Here I used 1000 finalgather rays.
Minrad = 0
Maxrad = 10

RESULT:
The shadows I wanted appeared.

Next, I'll set the minrad to 1 and maxrad to 0.

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