(FLASHBACK) Lighting Challenge #5: Under The Boardwalk


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



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. :banghead:


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…



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.



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 :love:

Confused much? Join the club



Just had confirmation from Vlado @ chaosgroup that the ‘bubble’ is indeed only required to return the correct fog result for the water, if you’re not using refraction fog for your water (in vray) then you dont need the bubble, although you will still need a relatively wide angle camera to capture the snell window



That’s really great, thanks a lot for your help. Now we can move on with correct settings without eyeballing it. :wink:


No probs, happy to help

“If you know it, share it!”


Hi guys, i will put a tutorial together that shows step by step how i have set my scene up thus far.Then we can compare notes and grow together :wink:

For those interested, here is an animated short film that takes place underwater.I was responsible for the lighting, shading, rendering and compositing.It’s stylised, but it might serve as inspiration :wink:


Will get cracking on the tutorial soon.




Hi guys, here is a breakdown of my scene so far.I use Lightwave 3d, but the aim of this breakdown is that it might share some ideas that could be used in any 3d package.I love working in Lightwave, it’s very user-friendly and the tools are easy to comprehend and use.For those of you that might be interested, i have added a link to an interview that 3D World Magazine had with me on the use of Lightwave in our animated short film, “Hooked”, which also takes place underwater.

I would like to point out that this is not the final layout that i’m using for my scene.I start off with a basic scene so that my test renders go nice and fast and when i’m happy with the general lighting setup, i move on to adding additional geometry detail.

Something that definitely helps alot is if we get some good reference of an underwater environment that’s more or less like the scene that you want to achieve.Study the physical properties of what you see.I found it useful to write down specific elements that need to be achieved.

The first thing that i focused on was the fog volume that obscures our view as we look off into the distance.This definitely helps create the feeling of mass that the water has, water is transparent, but it has all sorts of tiny bits of plant matter and little grains of sand that the current could quite possibly have scooped up from the riverbed.

In this image we have the distance fog that i added for the general water mass.I selected a bluey green colour, purely because i find it aestheticly pleasing.You can do your own colour based on your taste.Not everyone will paint the same picture.My ref pic had more of a browny colour to the water mass and less fogginess, but this is now where i take artistic license and tweak it to my own taste.

My environment fog was created in 2 passes, one for the water mass and one for the riverbed floor, where i have ground fog to try and subtly give the idea of soil sediment being present in the water.

And here are the two fog layers combined.

Here are my settings for the fog in the screen capture.

And here are my settings for the water surface.The settings were boosted a bit and also tweaked not according to scientifically correct settings, but settings that i think looks artisticly pleasing.The settings were pushed so that the water still looks right through the fog, with my standard settings the water looked somewhat dull, but amping it up to taste kept the water looking right.Bump was added to the water surface, a procedural turbulence texture within Lightwave.I did find however that the bump wasnt enough to make my specular light react properly with the water surface.I then added the procedural texture as displacement to the water surface and voila!

I hope this information is of some use to you guys, please let me know if there is anything that’s not clear or sounds strange ;)If there is anything else anyone would like me to share please let me know, i’m not sure if my methods make sense, but i usually use my tools to achieve something that i think looks good, although it might not adhere to certain scientific laws :slight_smile:

Thanks guys,



Hi Ben, I saw Hooked in 3D world magazine a while back and it took my breath away, the style and execution is awesome! :eek:

Glad to have you on board for this challenge, I really like your layered approach as opposed to getting it all in one pass, it really gives the water a sense of depth and scale

Looking forward to seeing your image, we’ve all got our work cutout to create something even half as good as ‘Hooked’

Ant :thumbsup:


@afraine: It seem like I can’t get the snell-effect without the bubble (maya/vray) any thoughts on that?


Hi Niclas, could you briefly explain your setup so I can see what might need to be changed?



Glad to see this discussion taking place. You shouldn’t have to do anything special to achieve Snell’s window. It’s simply the way the physics works with the refraction of the sky. That said, the water surface will not inherently achieve this effect without a displacement map and/or bump.

Thanks for the info Cre8! Hope you have time to come up with a final image for the challenge.


Afraine - thanks for the break down :slight_smile:

Visua - the ground fog is really neat. Thanks for sharing.


Hi Kanooshka!

Yes, i would really like to achieve a final image for this challenge.Things are a bit hectic at work at the moment,got 3 commercial jobs runnning, so where i can spend some time on it i will.I’m planning on using Lightwave 11’s instancing extensively and some Z-brush’ing on the boardwalk legs.

It’s so cool to have this forum running, i’ve looked for other lighting forums, but this is the best one out there in my opinion.Thanks for taking the time to run it :wink:

Afraine: Hi mate, you know what, i’m sure your image is going to look great, especially if we see the level of precision you are putting into your research.That shows passion!Keep at it man :wink:

Cheers guys!



So my setup works as expected in 3ds max(@work with vray), and the same setup fails miserably in vray for maya(mac-version). Interesting :wink:


I also gave the model a crack,
my aim was to make something colorful,
not so much based on actual physical correctness.
It’s now much more looking like an aquarium and
not an underwater scene in the wilderness :slight_smile:

(Right click and “Open image in new window” for a 1280x720px preview)

Made with C4D and Photoshop.


Is anyone getting corrupted uv issues with the .ma and .obj files?


Hi everyone!

Some really nice pictures here…

Heres my try using maya (MtoA) its still wip but I wanted to try out some postproduction using Nuke (color corrections, fx)

…hope to post another more fine tuned version soon