Time Spring (Poetry in Motion WIP)

[Kira Vakaan]

Hi all,

I just wanted to share what I've been working on for the competition. Here's a test render:

My inspiration for this piece is long-exposure photography of water. I wanted to see if it could be accomplished with LuxRender. I'm pretty pleased with the result thus far, but real water has a lot more mist (white blurry stuff) than this. I'm sure this is due partly to the fact that real water has a much higher resolution than this test simulation. I might have to come up with a way to add it in artificially. If anyone has any suggestions, I'm all ears.

What I've done is basically to sculpt a riverbed, and then use Blender's fluid simulator to actually move water down it. The fluid resolution for this test was 130, but it will be much higher (probably a little more than 300) for the final. The shot is one second of simulation stretched over 400 sub-frames to avoid discreteness in the render. Each sub-frame was rendered to about 10S/p, making a final of roughly 4.08kS/p.

In my original idea, there are cherry blossom petals floating down the river, and I still have plans to add them in. We'll see how that goes.

Any comments or criticism is welcome!

[Abel]

That is amazing!

[binarycortex]

That is fantastic. For the mist I would suggest a particle emitter or something like that.

[Kira Vakaan]

Thanks!

For the mist I would suggest a particle emitter or something like that.

Yeah, I was thinking something along those lines, but I figured that a halo particle wouldn't be supported. I suppose I should really just experiment. Do you have any suggestions on doing halo-ish things with particle emitters?

[SATtva]

I'm pretty pleased with the result thus far, but real water has a lot more mist (white blurry stuff) than this. I'm sure this is due partly to the fact that real water has a much higher resolution than this test simulation. I might have to come up with a way to add it in artificially. If anyone has any suggestions, I'm all ears.

Simply use roughglass with moderate roughness as a water material. Don't set roughness too high to keep water transparent and fairly clear, but not too low either so it will reflect light more diffusely (with milky feel to it).

Amazing idea by the way! I've been thinking about something similar some time ago, but never implemented it. Great to see it finally done.

[Carbonflux]

Honestly I did not think such a thing could be done, really amazing, thank you for sharing this one

Also great textures on the rocks and the water flow looks quite good to me in general.

[Kira Vakaan]

Simply use roughglass with moderate roughness as a water material. Don't set roughness too high to keep water transparent and fairly clear, but not too low either so it will reflect light more diffusely (with milky feel to it).

That's a good idea. I've never used that material before, but I'll give it a try. Thanks!

Also great textures on the rocks and the water flow looks quite good to me in general.

Thanks. The textures were created using Blender's texture painting features on an 8k map (8192x8192). I always opt for the extra detail when I can spare the RAM and processing power. It really just makes the detail pop. And as for the flow, that's entirely thanks to the amazing fluid simulator. Could you imagine modeling (400 frames of) water? That's suicide. Blender is really just all-around amazing.

On the subject of workflow, I want to mention that I'm recording the entire time I work on this piece. When I'm done, the plan is to edit and voice-over some kind of tutorial/documentation of workflow kind of thing. Hopefully I can help at least one person out there.

[J the Ninja]

I'm really curious to see your fluid simulation setup and obstacle settings. I've had a lot of issues getting to "fly out" over a ledge like that, I find it often has a habit of sticking the surface and flowing around the edge instead, as though it suddenly becomes viscous when touching the ground, even though it flows easily otherwise.

Also, for mist...maybe try modeling a mist cloud and setting it to homogeneous+null? I would guess asymmetry would be positive and fairly high since the particles are water drops (transparent). The problem though is....Lux has no dispersion for volumes. Any of the core devs know how difficult that would be to add? We can already feed cauchy or sellmeier values into volumes, rainbows in mist would be a very cool feature to have.

[Kira Vakaan]

I'm really curious to see your fluid simulation setup and obstacle settings.

I'd be happy to share them.
Nothing too fancy, but I think the thing that would impact what you're after the most would be the obstacle's slip type. Use Partial Slip with a high value or even Free Slip. For this scene, the obstacle mesh I use is a (much) lower resolution version of the actual rendered terrain. Best to keep the poly-count low for these things. Another thing that'll matter is your resolution; things seem to glop around a lot at the lower resolutions. Is there a project you're working on right now? What resolution do you usually bake at?

Here are a couple screenshots of the relevant settings:

Screenshot-1.png (10.26 KiB) Viewed 1208 times

Screenshot-2.png (6.74 KiB) Viewed 1208 times

Screenshot-3.png (11.07 KiB) Viewed 1208 times

[B.Y.O.B.]

I had the same idea (long-exposure of a river) for this competition, but I had no time to do it. I think I'll make something similar with the carrot branch of Blender (after the competition).
Your project is looking very good