mental ray stories -Final Gathering- - Page 2

# 16 08-12-2002 , 03:39 PM

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mental ray stories -Final Gathering- 15

With FG rays still at 200, the light angle is 5 degrees, with 10 shadow rays.

The result is still not good enough.

The manual says you can reduce the light-angle to reduce graininess, but I still want to puch up the number of shadow rays.

Maximum shadow rays are 40 !

Next, I'll go for 20 shadow rays in my directional light.

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# 17 08-12-2002 , 04:12 PM

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aaaa.. somebody stop him!! LOL user added image

nice thread undseth.. keep it up!

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# 18 08-12-2002 , 04:33 PM

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FG rays still set to 200.

Light angle set to 5 degrees.
Shadow rays set to 20.

Well, it is better but I have to push it even further. I would have but now I want to model something. ;

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# 19 08-12-2002 , 06:20 PM

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A room with a sky view

Nothing special, just a few renderings.

The walls are white.
The sky is... well, also white.
Directional Light (as sunlight) with intensity set to "1".
A nurbs sphere 180 degrees around the small scene, with incadesence material set to about 25%.

And FG rays set to 200.

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# 20 08-12-2002 , 06:42 PM

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mental ray stories -Final Gathering- 17

Blah! I had a rendering here but I missed the save option from the renderview and accidentally hit the render button. I lost this one.

However it was a bit too bright I think.

Next, I'll do a super render user added image

I'll go for 8000 FG rays.
Sampling: Min 1 Max 2
MinRad: 0.01
MaxRad: 0.1

edit:
Actually, when I come to think of it, the rendering wasnt lost, maya saves all my renderings automaticly in iff format.

Last edited by undseth; 08-12-2002 at 08:24 PM.

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# 21 08-12-2002 , 08:28 PM

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mental ray stories -Final Gathering- 18

Hmmm... This super render wasnt as good as I hoped it would be. But maybe it has to do with something other than the settings I have been working on.

The pic below is compressed to jpeg, but the original has a bad/less good transition betweent the shifting hues of the light.

FG rays = 4000
MinRad= 0.01
MaxRad=0.1

DirectionalLight Intensity = 3

MinSample = 1
MaxSample = 2

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# 22 08-12-2002 , 10:39 PM

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FG rays = 10.000
MinRad = 0.05
MaxRad = 0.5

MinSamples = 1
MaxSamples = 2

This picture is "smoother"

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# 23 09-12-2002 , 12:59 AM

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It's great to see your experimentation.

Thanks

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# 24 09-12-2002 , 09:21 AM

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mental ray stories -Final Gathering- 19

A LITTLE FOOLING AROUND WITH MIN/MAX RADIUS

This scene consists of these elements:
-180 degree nurbs-sphere, with incandesence material set to about 50%. This shere is located just outside my scene. It acts as a light source, but dont ask me why I need a light in the scene to make it light my scene with its incandesence vaule.
-Scene objects, most objects are colored white, while some has the heavy metal shader on it.
-A directional light, whos intensity is set to "0"

-FinalGathering Quality is set to "PreviewFinalGather".
-FG rays = 200

The size of this scene is 10 for the centered scene, and about 20-30 for the floor.

In this first rendering I set some very high values here for fun.
-MinRad = 1
-MaxRad = 10

RESULT:
Well, the rendering is spotty, but still quite nice for a preview (I think). Wow, the diffuse here is awsome. I have read somewhere that you can map the sphere with an image to give it some varying light shining onto the scene. Maybe a hdri image would be cool here user added image

, for both incandesence map and reflecion map.

I will do a great rendering at the end of all this to hopefully sum up my experience today.

Last edited by undseth; 09-12-2002 at 09:45 AM.

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# 25 09-12-2002 , 09:59 AM

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mental ray stories -Final Gathering- 20

MinRad = 0.5
MaxRad = 10

RESULT:
The diffuse is still grainy after redusing minrad from 1 to 0.5.

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# 26 09-12-2002 , 10:10 AM

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MinRad redused to 0.2.

RESULT:
The grainynes has not been recuces at all it seem. I'll reduce the minrad a bit more and then try to figure out how the max rad changes things.

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# 27 09-12-2002 , 10:40 AM

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mental ray stories -Final Gathering- 22

Ah, here's something I have discovered.

Although some of the diffuse on the floors are still the same as the first render, in this latest render, the diffuse on the colums seem to be grainy, but in a tiny way. I take that as a good omen.

MinRad was 0.01

But I suspect that maxrad has some major role to play here, I'll do another render, starting with minrad back at 1 and decrease the maxrad, like I did on the minrad setting.

Last edited by undseth; 09-12-2002 at 10:43 AM.

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# 28 09-12-2002 , 11:08 AM

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mental ray stories -Final Gathering- 23

Came to think of it, that I probably know why there is a minrad and a maxrad setting. I recon the mentalray works best/fastest if it can treat the scene varyingly in a render. I guess.

MinRad = 1
MaxRad = 5

RESULT:
So when I reduced the maxrad from 10 to 5, the result got better. (I already knew that 10 was too high, but I had to try it out)

Im not sure how low the minrad should be. I will go a little further down with the maxrad and change the mentalray render globals "quality" to production to get a final render.

Im not sure what is concidered a good solution in "PreviewFinalGather" mode. So I'll do a final render soon with some average min-max-rad settings and then some better ones to see if the previw mode is a good way to work with if you want to fine-tune your renderings in a time-saving way.

Last edited by undseth; 09-12-2002 at 11:12 AM.

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# 29 09-12-2002 , 11:23 AM

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Great work Undseth! A great thread for anyone wanting to get to know MR!

Fantastic job..

I will add 4 points to your VIP subscription in appreciation of your work user added image

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# 30 09-12-2002 , 12:04 PM

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mental ray stories -Final Gathering- 24

Thanks Kevin! user added image

In this render the minrad was at 1 and the same vaule was set to the max rad. I would probably set the minrad lower for better renderings but I'm just fooling around here.

RESULT:
The render is better and the grains are smaller all over I think.
------------------------------------------------------------------------------------
I will now take a look at the differences between the PreviewFinalGather and Production mode.

Default MAX REFLECTION RAYS
Preview = 2
Production = 10

Default MAX REFRACTION RAYS
Preview = 2
Production = 10

Default MAX RAY DEPTH
Preview = 4
Production = 20

My FINAL GATHER RAYS
Preview = 200 set by me
Production = 1000 (default I think)

DefaultSAMPLING QUALITY
Preview = min -1 and max 1
Filter = Triangle width = 2 and height = 2
Production = min 0 and max 2
Filter = Gauss width = 3 and height = 3

I looks that these are all the parameters that is different in the defult settings, between the previewfinalgather and the producion quality.

I will do a production render now with the settings above. The production quality will have the same min- maxrad settings as the preview mode. Which is why I used the preview menues in the first place. The finalgather rays is beefed up to 1000, with a higher sampling value and a different sampling filter.

Im not sure about the filter thing, but the sampling gets rid of those jaggy edges. Most prominent in edges that arenet quite 90 degrees perpendicular(?) to the ground plane.

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