Fun with primitives

A cube with a plain water texture and then a plane with a caustics texture below it and under the G1 figure. It was an experiment to see how it would work.

Limited results due to the textures themselves — perspective is all wrong — and it didn’t really give the illusion of depth I was hoping for, but it was worth a try.

I’d like to try a render project similar to this concept:

Biggest problem: it would be hard to find a hair prop that would convincingly look like it was floating on water.

Also, I’ve not had much luck getting water materials to look good. I have UltruMarine, but that’s for underwater scenes. I don’t have Ocean Wide, by the same vendor, but maybe that would be better than using a cube and/or plane with a displacement map. Then again, while that prop might look more realistic, a flatter plane would probably work better with a “floating hair” prop, providing one even exists.

Any ideas for a hair prop that can do this? I have SAV Zero Gravity Hair but, again, it’s one better adapted to underwater scenes. Also have Warrior Wet Hair G3M and Christine Hair V4, both are close but lying flat in the wrong direction (great for any floating Ophelia render projects though.)

Not that dForce works for me, but I wonder if this is one of those instances where it would do exactly what I needed?

12 thoughts on “Fun with primitives

  1. Dforce might be “the” solution here but only in theory because hair is not that easy to dforce: most models have intersecting polys from the get-go => crashes.
    Deformers might help!

    You would generally want some refractive surface material with Fresnel for the water (and a skydome to be reflected in there) – with a nice enough displacement map and the right sort of stuff on the skydome, this should look quite convincing, even on a simple plane.

    Caustics is concentrated light, so it’s brighter than the surrounding seabed… and if you make a b/w caustic-light-only map by playing with curves, you can put this into ambient strength and then caustics should sort of light up.

    As for water depth, I think zigraphix had shader mixer water cameras with depth extinction – they might have even been a freebie at some point, I honestly don’t remember – with a small tweak these volumes could be applied to primitives instead of cameras. But they are shader mixer so most likely will render slow. So see if you get nice results from other tricks first.

  2. I don’t think dforce would help you with this project. There are lots of different directional vectors that go into how hair floats on water. With dforce you only have gravity and wind. On water there is surface tension and a body that is disturbing the water in a particular way. I would suggest that you take a primative disk and drape it over the top of the head. I would use Poser for this but if you have the converter for Opitex from Rendo, you can use that in Studio. Use a plane to define the water level. Drape and create a UV map. I would look to Koz’s hair textures for guidance with the texture, highlights and shadows, and then do a transmap to rid those areas of polygons that are not needed. You might be able to use SAV’s Fashion hats. I think there is one with a brim if you do not want to play with dynamics. Poser has a disk primative that might work.

    • Hey, continuum mechanics major here. Please correct me if I’m wrong, but it seems to me that you’re under the impression that dForce is fundamentally different from Poser cloth room or the Optitex draping engine and that it is somehow deficient.

      It’s actually not. It may well even share code, who knows; there is an open source lib or two floating around. And all in all, most solvers come down to a few known continuum models anyway.

      Explicitly specifying surface tension is not necessary for this problem because we are not solving for whether the hair will sink or not; we assume it’s light enough to float. Consequently, the deformation of the water surface under the weight of the hair isn’t really going to be that significant at a distance.

      You’re right that we need a wave pattern for the disturbance of the water. It can be approximated with a deformer on the water plane set to create concentric “waves” by editing its spline.

      Now, as to the primitive disk suggestion. DS has no primitive disks unfortunately.
      Moreover – the result of draping a continuous disk vs draping a bunch of ribbons would look different. It may be ok artistically – or not; this is something to be determined in each particular case.

  3. I did a challenge over at Dreamslayer Artworks to learn about caustics. To make 3Delight create caustics you will need a caustic camera and caustic light. The surface of your plane will need to have the caustic shader applied to it. Since you have Studio 3 installed there is a sample scene for caustic light creation that can be used to play with. I found it hard to get the caustic effect. Lights, camera and surface have to be orientated appropriately and I found no magic tut that could tell me how to do it well. I noticed on one of your suggested products that they used gobo masks on lights to fake the caustic. I would try the texture on the surface plane in the light and see if that works.

    • There is no magic, you’re right. Just work. Same as IRL actually, try positioning a crystal jug just the right way to get pretty caustics in your photo… wham, the sun moved, back to square one.

      For the case of water ripples – more than just a camera and a light.

      First, you will need to use a solid (like a cube) rather than a plane, because 3Delight only calculates caustics when they _leave_ the refractive medium. In other words, it assumes that the exit interface is defined by normals pointing towards the light source. Your seabed has to lie underneath the bottom face of the water cube.

      Next, you need the water to have disturbances – because IRL it is those concave and convex shapes that bend the light and hence create caustics. Simple concentric waves won’t give you the same pattern. Editing caustic photos to make a displacement map should work in theory… but getting a map nice enough will be even more work.

      This is why even pro VFX, even today, will likely “fake” caustics whenever they can get away with it. =)

  4. Wow! Thanks so much for the detailed feedback. A lot to consider and play with too.

    Sometimes I get so frustrated because all I want to do is make an image but to do what I want requires all sorts of complicated side adventures. Ugh.

    I was eyeing that floating hair image again and thinking how I could do the effect in postwork. The Mesh Warp tool, hair brushes, Topaz for a unifying illustrated look. I dunno. I might even be able to find a free or cheap stock image and just blend that with a rendered face more like I have in mind.

    I bought that dynamic utility at Renderosity but — just my luck! — it didn’t work for me. The old Optitex plugin still works, for the most part, but nothing newer. I followed the instructions that came with the Rendo utility but it just sank the plane into the “floor” without ever doing any draping.

    I can barely make my way around Poser; the idea of trying to learn to use the dynamics is almost overwhelming, to be honest. I wish there was an easier way to find a balance between learning things and making pretty renders.

    I would’ve never considered turning a hat into dynamic hair though. What an awesome idea!

    For the little toony mermaid scene I think I’d prefer more toony-looking water, but other kinds of water image ideas pop up in my head all the time and so the refraction, fresnel, reflection, and caustic issues are all something I really need to better understand.

    I’ve tried playing with refraction but most of the time the results were…well, pretty horrible.

    What I should do for starters is look at the 3DL settings for any water props I do own and see how they’re handled.

    Kettu, I found that water depth camera product you mentioned. It’s in the wishlist; thanks for pointing it out.

    I have the Howie Farkes Harpwood Trail for DAZ Studio and there’s an add-on for it — Mallard Pond — that’s been in my wishlist for quite a while. Next time it goes on sale I should get it. It looks like it would work for most of those water-related ideas ratting around my head.

    • You’re welcome!
      I wrote a couple more techie observations as replies to DollyGirl =)

      That pond looks nice in terms of water surface relief, but I wouldn’t trust its material settings. If you try swapping the 3DL and Iray promos (no. 3 and 4), you’ll see the reflection of the trees doesn’t seem to dim as your eye goes towards the bottom of the pic (= closer to your vantage point). While it should. This is the whole Fresnel thing: if you look straight at a non-metallic surface, it will only reflect max 5% incoming light at you.

      Tell you what, I hope to have a few minutes free this week (we have that May 1st celebration here and it gives us an extra day off), so if no emergency distracts me, I’ll make an as-convincing-as-technically-possible (free)UberSurface-based water material for you, and an optitex version of that bunch of ribbons I see as a plausible model of floating hair. But you’ll need to texture those yourself =)

      • Oh wow, that would be awesome! But don’t feel obligated, okay? If it’s fun and a challenge for you, then I’ll feel less guilty over you taking the time to help me with some little, insignificant project. 🙂

        Mind you, I should still learn these about all this but there is a line where I get too frustrated and just give up. There’s no shame in admitting there are some things I’m simply not good at.

    • Thank you for sharing the render! That is pretty close too. Did you ever get any movement?

      I wish dforce worked for me…

      Also, sorry for not responding earlier. Some little personal issues with a sick pet. 😦

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