Nice fish tank technique?

[tricky]

I need to render a big fish tank - 1m x 1m x 3m (HxDxW). It will contain jelly fish (though I can add these in post.) and will be lit from above. I am not sure which method to use: refraction with glossiness, fog, 'soft' translucency etc etc. Can anyone give me some pointers or point me to a tutorial?

Also, do I *need* to use caustics? I am aiming for a good look and am not too bothered about a physically accurate way of doing it (though I appreciate it is often useful to work from a physically accurate perspective)

[tricky]

...also, should the body of water (a cube) have its outer edges co-planar with the inside faces of the glass tank?

[percydaman]

dont make them coplanar, rather have then overlap just a tad.

[re:FORM]

overap? I always made my surfaces apart a tiny distance.... perhaps thats why my glass and liquid never looked great!

[tricky]

But how about rendering/material technique?

I have so many options I am not sure where to start:
Opacity
Refraction
Translucency
Glossiness - reflection and refraction
Caustics
......etc

[re:FORM]

I think the most important thing to make fishtank side view look convincing would be to get the particles and bubbles looking right... Also the IOR between then glass and the water should be high so you get that strong lensing effect (if the camera is animated).
Although you probably know all that already!
Sorry I cant offer more suggestions.

[tricky]

Its all useful info, and I agree about the bubbles etc.

I'll probably end up Photoshopping the thing anyway, but it would be nice to see how far I could get with a 'straight render' approach. I have just never been sure about caustics, translucency and glossy refraction and if they need to be used all together or on there own...

[DaForce]

Surfaces interaction. (check it out too re:FORM)
http://www.spot3d.com/vray/help/150R...sinterface.htm

And caustics.. well allow me
http://www.chaosgroup.com/forum/phpB...light=caustics

That should be all you really need. Just make the faces overlap a tad vray will take care of the rest. And if you want to use caustics.. see link above

[re:FORM]

Thank daforce.
Its interesting(in terms of the mechanics of vray) that the overlap provides the best solution. I would have thought you would end up with problems caused by reflection between the inside surface of the water (within the glass) and the inside surface of the glass (within the water)... but as shown in the manual it works a treat.

My lack of understanding probably comes down to me being too lazy to sketch out the different IOR's at the point where the water overlaps the glass and working out the lightpaths.....

[DaForce]

Its actually coded into vray to work properly that way. Before overlapping faces wasnt not good
What people used to do was is have 3 surfaces. The outside of the glass, the water top and the inside of the glass/water.. and there was a specific set of IOR's assigned to each. The inside one, being a division of the other 2 or something.

But vlado coded in this easy overlapping method.

Trying to find that old post now.. will edit when i find it

[Ryan_Chiong]

its in the vray documentation. rendering surface interfaces under tutorials

[DaForce]

You mean the one I linked too a couple of posts up

[Ryan_Chiong]

yeah!

i missed that post. sorry.

[RErender]

Should be a rule. No posting in a thread until you have actually read it.

[Ryan_Chiong]

apologies master

now i know its not good reading posts while working.