Hi all,
finally posting some work here, for I really need some crits on this one. It’s from an animation.
The main issues is the DoF (faked by blurring using the Z-buffer) on the closer stones and the caustics (is it, the sparkling lights on the bottom of water on a sunny day?) I haven’t been able to get them better.
Thanks for all comments in advance!
looks good 
i like the water and the fake causistics… the Platypus which should be the main focus of the picture is quite camouflaged… it took me a while to see it… maybe add some more lighting on the Platypus so that the viewer can see it?
I actually quite like it camouflaged, makes it a very interesting picture and makes you all like “Woo!” when you actually find it, lol. Might just be me though.
The platypi’s camouflage helps make this image really realistic. The fake caustics really aren’t that bad, maybe a little tweaking to make them sharper but thats more of a preference.
What would really add alot to this image would be murkiness to the water (using nodes attached to the zbuff would be the easiest, using volumetrics would be accurate but probably extremely hard to setup and the render time would be through the roof)
Adding the murkiness would make any dof errors less apparent 
also, if this is a sunny day, make the water more blue! it’s really gray and sickly looking now. You could probably do this with nodes as well, but I don’t know much about color correction in blender.
Thanks for the input.
The murkiness is already there, only the “murky curve” is a bit too progressive, and it’s done using the Z buffer. Anyway, has anyone seen a z-buffer output 30 times multiplied values? Because that’s why I haven’t been using the compositor for a while…
Bluer water looks better, I thought it’s been too cold but couldn’t figure out why.
I’ll do some more tweaking and see if I can get the right look.
Right, that’s much better…
Made it brighter, added some better environment out of the water, made the DoF subtler and fixed some bugs that were in the node noodle (a ball of spaghettin in my case).
And a raw render (no nodes) just for fun.
Attachments
Just when you thought it was safe to go back in the water . . .
wow, that looks really cool. I would bring the platypus towards the camera some more though
That’s a pretty good render, however I do think that the one on the left looks more underwatery, because the the slight fogginess of it.
I have a few crits, first of all, the platypus almost blends in with the background and so you should probably make it stand out more, second, i think it should look more like it’s underwater so if you could somehow add a light ray effect: 
and maybe some of that light like shown on left, xept with maybe a strong DOF, then it would look believable
First of all, most animals do not “stand out” of their surrounding for obvious reasons of being eaten. I believe it’s fine the way it is.
Light rays however, are a good idea.
Thanks for the replies!
It’s a frame of an animation, the platypus is gonna get nearer a bit later. I think he’s just as visible as I want him.
bojo600: I’ve been experimenting with the rays earlier but haven’t found a beliveable way yet. I’ll put in some more research, but the water and background is so bright that they probably wouldn’t be visible anyway in a real river.
Maybe you could add some tiny particles to help add to the realism of being underwater as little rocks and bits of mud would be brought up from the riverbed carried downstream. It might also help give a little more depth. But I’m loving the image keep up the great work!
It’s looking much more natural now, though still not murky enough in my opinion (ever stick your head in a real creek/river? 10 feet is about as far as you can see) but on a more important thing i noticed, theres no plants :o
maybe just a few leaves embedded in the bottom, a couple weeds, plus DustyKhan’s water particle advice.
Here’s a ref for shallow river/creek murkiness, and this is for water foliage/moss.
Your creek/river in your render is almost to scale with the creek next to my house… sadly I lack an underwater camera to give you some references, though if I find my old, really crappy camera I may just find out how waterproof a ziplock baggie is
I love it! I agree that it needs to be more murky though… platypuses naturally live in water that’s really murky, that’s why they have that big “bill” to feel their way around while submerged.
Oh, thanks, I’ll try. When I look at it now (after not having worked on it for about 3 days), I see the murky problem. And I sure haven’t thought about plants, that’s a great idea!
I’m assuming your still working on this scene?
If you are, i think that your platypus is a bit too fat/big. I saw one a few days ago, and it was quite flat. It was also a bit skinnier than yours. I suppose that make the swim more efficiently.
As for water, if you wanted it to be a 100% realistic platypus habitat, you wouldn’t see the platypus. the water they live in is muddy becuase when they use their bill to search for food, they disturb the mud (and make it muddy!). They search for food all day long, becuase they use up most their limited energy(from their food) by searching for it and keeping warm (because they aren’t fat). So i would make the water a little bit more muddy.
For that reason, they also are rarely seen swimming the way you have yours, they’ve either got their beak in the mud or they’re on the surface for a breath. They also swim using their tails, their limbs tightly held agaisnt their sides. You could have swimming up for a breath, that would look alright.
Sorry for the long essay , but being from Australia, and living within an hour of three different platypuses in captivity, i’ve seen them alot, so your image stood out to me.
Other than that, it’s a great image. I would maybe lower the size of some of the rocks.
Sam
I would suggest adding some aquatic plants to give it more interest and depth. really nice though.