I am trying to create an image half underwater, half above water. The thing is I am not sure the best way to go about this in blender. I will post my tests when I get home. In the meantime, does anybody have any suggestions of how to accomplish such an image.
Please see links for a couple of examples:
Image 1
Image 2
Image 3
These are my first tests, and I feel that they have turned out ok, but still could be improved.
I haven’t added any proper textures to any of the objects yet.
There has to be a better way for me to do this.
I have a ground plane, a plane for the water with a displace modifier and a cube with a volume material applied. I still need to add caustics which I will do with the use of an area light and a texture…?
Does anybody know if there are any other things that I would need to add or do to make a scene like this believable?
Neat, you did it pretty much the exact way I did it before seeing the second post. Even down to the caustics being a light texture. Only difference I see is that I messed with the foreground water line a bit to simulate what I saw in real photos of this sort. but that might just be a personal preference because I saw many cg ones that looked good without that blur.
As for my version I’m still not happy with the underwater lighting, too dull and flat, but that has to do with my own inexperience with volume materials.
I have to ask now, but is this in preparation for an entry for the current blenderguru competition? if it is that’s cool and go for it. but if not I might take the basic concept on farther and make an entry myself.
No its not for the Blender Guru competition, so go for it! I wish you the best of luck! So is the front edge of the water near the camera given that ‘thickness’ just from a blur? would you mind showing me how, as I cant figure it out, but It helps define the surface of the water.
Another thought I have had is to use two cubes both with the same displacement then delete the sides and bottom of the cube with the water texture, then with the other give that the volume material, then it should match exactly the surface of the water. Not sure if there is any benefit to that.
no, it’s not just the blur. I just curled down the edge a bit to add the thickness, then added an object around the camera (just out of frame) to simulate the camera body in the reflections on that lip. (Note that to do this you’ll need to position the water object so it actually ends just before the camera clipping, instead of relying on that clipping distance to cut the waterline mid object. the down fall I see is this is not good for moving camera animations, at least anything other then side to side scrolling, but water wave movement should work. and anything with camera movement probably doesn’t need such fine detail anyways.) :eyebrowlift:
As I said, the water lighting looked too flat and unattractive to me. I’ve never been able to get very good results out of the volume for anything other then fairly dense volumes (smoke, fire, ect…) so I dumped the volume method and just did it all with nodes. So far I think it’s looking better, and I’ve got a lot more control now as well. the basic idea is I made a mask layer, made a caustic layer (buffer lamps with halo’s on a black backdrop) and mixed in the z-depth, caustic layer, and masked that in the final image just below the water line. I can explain more if you want.
Still to work on as I see, further improve the lighting on objects mid water (legs and feet in this case) and a way of faking some heavy bokeh/blurred particles in the extreme foreground.
PS. sorry about the odd border on the image, blender decided it didn’t want to save the image for some reason, so I had to screengrab it and crop.
Its looking good. Yeh it is a tricky one to get the under water lighting right. If you wouldn’t mind elaborating on how you are creating the under water mist, that would be really helpful, perhaps share a .blend with the node set up?
Could you not create a separate light group that only lights your character to make her (Sintel…?) standout more, as I also feel she is a little to dark, but could also help her become more visible under the water.
I have added some blur under the water in my scene now, but don’t know how to do the ‘god rays’. I feel they really add to the scene. Under water microbes/dust/plankton next 
One other thing I have noticed is the objects underwater can be seen reflecting/refracting on the water surface, and this I don’t want happening. I will need to sort this out. Need to create a better water and caustic material also!
BA deleted my post after a time out before posting, and I don’t feel like re-writing it all right now. So You’ll have to content yourself with the node set up for now. There’s a lot of other stuff going on here, much of which is unnecessary, but you should be able to follow the basic important things by knowing that it goes Z-depth pass > “map value” >“god-rays” layer > masking layer to mix into the main image. The rest is just minor color and value adjusting and the blur which have all become a mess after too many revisions. I really should remake it from scratch so as to clean it up and refine the methods used.
Edit: So you can see what this exact node set up renders, as well as one of the rough idea’s I have running about in my head at the moment. Render time’s for the two side layers is minimal (a few seconds) and render time for the main layer is still under 2 min., SSS pre-calc and node composting time included.
Not sure if there is any benefit to that.
Thanks Atemporalskill, its appreciated. I have also been timing out when writing posts lately :S I will look at this over my lunch, then get back to you with something this evening. If you could possibly post a screen shot of the main nodes just for the mist and rays, as I cant make some of them out, that would be very helpful.
So are the god rays spot lights with halos rendered in a separate layer, or have you used an image?
Im liking the particles you have floating in the water. Very nice, maybe just give them a little more blur 
Uterine Fibroid: No benefit to what? Could you explain a little.
DustyKhan: yeah, sorry about that, BA must have downsized the picture on upload. for the “godray’s”, an image would work fine too, but I’m using a render layer so as to make the rays interact more with objects in the water. Here just take a look for yourself, this file should do all the basics, but there is obviously a lot to tweak before the results are really looking good in each particular usage case.
ATS Example Half Underwater.blend (228 KB)
Also I noticed that I’m running into AA issues, on the foreground blur. Normally I’d just check “full sample” and it’d be mostly solved, but I seem to be having problems with that and multiple render layers rendering and showing properly while it’s checked, so if you know much of anything on that issue please check it out.
Thanks for sharing that 
I have taken your node as a reference and started building my own. I have realised it seems to be the Map Value node to create the fog that causes the AA issues, not the Blur node or defocus node, cant seem to find a way to fix this.
I cant seem to render out all the layers properly, should it not render them all at the same time? the image below is what I am getting (I’m quite new to compositing in blender sorry if I am being a pain)
Haven’t had as much time this evening to spend blending as I would like, but start of the weekend tomorrow so lots of time then to get this working
If you’re getting what I think you are, never put a map value output (gray circle) directly into a color (yellow circle) mix node, run it though a color ramp first and that should solve those problems. Has to do with being a different data type, and while it kinda works it causes a lot of artifacts that look a lot like AA issues. and no, your not being a pain, if you where I wouldn’t be here still. 
but regardless their are depth/blur area issues anytime you fake a foreground blur like this, to which the only solution I know is true rendering of DOF as the new cycles engine does.
yeah, sorry about not explaining that, I’m fairly noob at render layers myself. So I couldn’t figure out how to get them all to render automatically ether, so I just did it manually.
In the file the main render layer is 1 and 11. Or top left of both groups of ten of layers, not sure what the actual numbers are. But I assume 1 -10 is the first set left to right top to bottom, 11 - 20 being the same on the right hand set. And sorry, you can combine 1 and 11 to one layer if you want, I just have a habit of putting the camera and lights into layer 11 to get them out of the way when working on my scenes.
The other two layers are on 2 and 3 respectively, I do have it set so it’ll only render out the layer selected in that layers panel. (the little thumbtack to the right) to ensue that they render correctly just match the selections of “scene” to the ones pressed in “layers” just below that box.
If anybody knows what I’m doing wrong that makes them all render correctly for their respective layers at one F12 stroke I’d love to know.
@Atemporalskill[/B]Atemporalskill can I have the blend file of your half underwater scene?
I dont understand it and i will learn!! =)
Jurek: um, yes, the download should still be available there on post #10 for the example scene I made to share with anyone who wants it. Also it would probably be a good idea to read DustyKhan’s question about the file and my reply so you know how to render the “render layers” correctly.
also you should remember that this is just one way to do a half underwater scene, some variations were discussed at the beginning of the thread.
I don’t know if it was mentioned - here is nice tutorial about it - but it uses AE for compositing - still can be helpful