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Old 07-31-2012, 08:03 PM   #31
CPFitz14
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Nice images Afraine. Could you talk a little bit about your scene setup?

What is the material/IOR around your "bubble" surrounding the camera. Is your water just a surface or is it something enclosed, like a box? Which way are the normals facing on the bubble and water surface?
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Old 07-31-2012, 08:16 PM   #32
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Quote:
Originally Posted by CPFitz14
Nice images Afraine. Could you talk a little bit about your scene setup?

What is the material/IOR around your "bubble" surrounding the camera. Is your water just a surface or is it something enclosed, like a box? Which way are the normals facing on the bubble and water surface?


Hi Fitz,

IOR on the water is 1.333 (typical water) and the same material with the same IOR is applied to the bubble around the camera (a sphere basically). The normals on the bubble need flipping so that they face towards the camera (hope that makes sense)

Oh, and the water is just a surface, no box or volume

If anybody wants a simple version of the scene, maybe an .obj file or something I wouldn't mind sharing. I'm aware that not everybody here uses Vray otherwise I would offer a sample scene with the materials

Regards

Ant
 
Old 07-31-2012, 08:37 PM   #33
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Ahh that totally makes sense. Thanks! I was overthinking this one.
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Old 08-01-2012, 10:12 AM   #34
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Hi guys,

Here's my shot so far, i havent done any form of texturing yet, only lighting and adding instances for foliage on the rocks and soil.My shot's layout is also still going to change, ilike to get my general lighting down first and then go into enviro detail. My volley layer also has a few changes that i will apply to it, i need to slice the tops of the plants that protrude through the water.

My link: http://i1241.photobucket.com/albums...e_BenCooper.jpg



Please let me know what you guys think.I have a few bubbles here and there, but will still be adding particle matter in also using instancing

Cheers,

Ben.
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Old 08-02-2012, 12:09 AM   #35
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Oh this brings back some memories!
A quick mockup with low sampling, maya/vray and some postpro:

 
Old 08-02-2012, 12:34 PM   #36
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Quote:
Originally Posted by afraine
If anybody wants a simple version of the scene, maybe an .obj file or something I wouldn't mind sharing. I'm aware that not everybody here uses Vray otherwise I would offer a sample scene with the materials

Hi Afraine. It looks pretty good. Could you PM me the simple scene with just the sky and the surface, so I could explore the effect you created? Thank you. So you used regular physical water properties, is that correct?
Quote:
Originally Posted by Cre8

.

I think your water looks the most realistic for now. Could you tell a bit how you made the water surface, so it looks so believable? And maybe some kind of gradient adds to the feeling, or it's just the water plane setup is so good? Thank you.


I think what's important with Snell's window is the index of reflection. I tried settings from 0,9 to 0,7 and they look more or less believable.

Last edited by mister3d : 08-02-2012 at 01:32 PM.
 
Old 08-02-2012, 01:33 PM   #37
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Hi Mister3d

I'll send you the scene when I finish work later this evening

The water has regular settings, a bit of noise for the small wavy effect and IOR is standard water (1.333)

I've been modifying the scene somewhat but I'll send you a simple version of my setup for you to explore

You're using Vray I believe, which version of Max do you have?

Ant

Edit - http://www.anthony-fraine.com/wp-co...12/08/snell.zip

You can use this scene which came straight from Vlado @ Chaosgroup, I take no credit for it

All I have done to differentiate my scene from the one in the link is remove the fog and the bubble which surrounds the camera, I originally thought the bubble was needed to return the correct effect (Snells window) but it seems that the bubble is only required to ensure the correct refraction fog colour is returned

One negative effect of wrapping the camera in a bubble is that technically you are rendering through something (in this case water) and so the only useable element would be refraction, this is obviously quite a bad thing as you in effect get no elements and may as well just colour correct the RGB. Removing the bubble allows you to render a normal image and have all of your elements available to composite with (much better!)

Ant

Last edited by afraine : 08-02-2012 at 01:47 PM.
 
Old 08-02-2012, 01:36 PM   #38
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Quote:
Originally Posted by afraine
Hi Mister3d

I'll send you the scene when I finish work later this evening

The water has regular settings, a bit of noise for the small wavy effect and IOR is standard water (1.333)

I've been modifying the scene somewhat but I'll send you a simple version of my setup for you to explore

You're using Vray I believe, which version of Max do you have?

Ant

You can send me any version till 12.
It's interesting. Snell's window is created by reducing the angle of view to 96 degrees instead of regular 180. I'm curious how to transfer 180 degrees to index of reflection.
 
Old 08-02-2012, 02:00 PM   #39
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Wink

Snells window returns the effect of 180 degrees compressed into a 96 degree viewing angle but nothing has to be altered physically to return this result, this is just what happens when setup correctly. In other words, Vray will produce this result naturally without any tricks or fakes required

Hope that makes sense, I've edited my last post and added a direct download link for the original scene file (from Vlado at Chaosgroup!)

Just remember, normals for the surface water (made of a simple plane) should point away from the camera. If you decide to use the bubble approach as demo'd in the sample scene, then the normals of this bubble (a sphere) should point towards the camera
 
Old 08-02-2012, 03:10 PM   #40
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Thanks for the scene Anthony. Is there any chance you could capture some of the scene set up and important settings for me to see? I only have Maya + Vray and no Max. Thank you
 
Old 08-02-2012, 03:17 PM   #41
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Quote:
Originally Posted by Panupat
Thanks for the scene Anthony. Is there any chance you could capture some of the scene set up and important settings for me to see? I only have Maya + Vray and no Max. Thank you


Certainly Panupat, i can recreate the scene for you in Maya when I get home, I dont have Vray for Maya though but I can share the settings of my Vray for max materials and you could translate them across into Maya, it's very basic so it won't take long

If I get chance before I leave work I will try to break the scene down into a simple diagram which will explain the basic principle

Ant
 
Old 08-02-2012, 03:18 PM   #42
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Afraine, thanks man. It's strange, but I still cannot recreate it like you did. Should be the water plane inverted so the normals facing the camera?
I setup material for the water like this: diffuse is black, refraction is white, reflection to fresnel, IORefraction to 1,33. And still it doesn't work.

Last edited by mister3d : 08-02-2012 at 05:27 PM.
 
Old 08-02-2012, 04:17 PM   #43
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Hi Mister3d, is that taken from the sample scene or from your own?

I may have missed one vital bit of information in my earlier explanations which is:

To capture the full window (Snell's window) the camera would have to be wide-angle, FOV of around 90-100 degrees I think I have gone for, or if you are using focal length this would need to be around 18mm

Your camera doesn't need this extreme wide-angle if you only want to capture part of the window

Here's a simple diagram...
http://forums.cgsociety.org/attachm...id=168601&stc=1

Ant
Attached Images
File Type: jpg Snell's_Window_Diagram.JPG (75.6 KB, 43 views)
 
Old 08-02-2012, 04:35 PM   #44
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Thanks Afraine. But do we need this bubble at all?
Yeay, I think it worked! I made it facing up with those settings, and it looks like in your scene now.
Here's my test. Looking from it, almost no-one made it correctly, except for Cre8, but I'm also not sure. The window looks surprisingly small, as I got used to another look first.

Here's an unwrapped version for everybody. In includes max 2011 and obj file formats. It was unwrapped fast, and you can improve of course.

http://www.sendspace.com/file/lwfupo

Last edited by mister3d : 08-02-2012 at 05:03 PM.
 
Old 08-02-2012, 04:57 PM   #45
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Quote:
Originally Posted by mister3d
Thanks Afraine. But do we need this bubble at all?
Yeay, I think it worked! I made it facing up with those settings, and it looks like in your scene now. If you need an unwrapped version of the scene, I can post it.


To be honest I'm not actually sure the bubble is a necessity, as I can achieve the Snell window effect with or without it, I think the bubble is to ensure that any fog colour applied to the glass is calculated correctly (at the water's surface and then again at the bubble's surface - creating the illusion of a volume between the two objects)

I haven't actually got it turned on in my scene at the minute but for a while I couldn't get the effect without the bubble, I've got a feeling that the HDR in my scene is compressed into the 96 degree window with or without the bubble, just through the natural law of refraction in water

There is a hidden danger with using the bubble that I may have mentioned earlier, none of your elements will be useable, only your refraction would contain any information (this is a big hidden danger to be honest) which is why I turned the bubble off in my scene, without losing the snell window. It's pretty obvious now I think about it as if the camera is inside the bubble, it needs to look through it (refraction)

I'm now using Vray Fog instead of fog applied to the waters surface as it accurately results in volumetric effects and just looks better

Confused much? Join the club

Ant
 
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