Path traced water animation, simple test

Started by Tangled-Universe, January 13, 2021, 06:16:36 pm

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Tangled-Universe

Simple test for a different purpose...Nothing really special, but some may appreciate it perhaps.
Rendered with PT AA4 and 25pps. Took about 18 hours.

gao_jian11

Yes, I like it very much. Beautiful lighting, clean rendering.

WAS

Looks very nice! Ive wanted to try rendering my river/stream idea but just takes too long. I have it so the center is a little more turbulent and flows faster, and the outside near shore flow a tad slower sorta deal.

Hannes

Cool! I'd say, the stones should be a lot more glossy and darker near the waterline. They look quite dry although they were just covered with water.
Nevertheless especially in the shade you can see, that PT makes a big difference.

Tangled-Universe

Thanks Gao and others,

Quote from: WAS on January 13, 2021, 08:03:18 pmLooks very nice! Ive wanted to try rendering my river/stream idea but just takes too long. I have it so the center is a little more turbulent and flows faster, and the outside near shore flow a tad slower sorta deal.

I can imagine rendering such setups with varying flow speeds etc. is slow. Otherwise I'd offer to help a hand with rendering. Does that setup really require PT rendering?
For this scene I chose it specifically, because I was just curious to see how PT volume scattering looks with animated water. The scattering is towards normal, btw.

Quote from: Hannes on January 14, 2021, 06:11:14 amCool! I'd say, the stones should be a lot more glossy and darker near the waterline. They look quite dry although they were just covered with water.
Nevertheless especially in the shade you can see, that PT makes a big difference.

Cheers Hannes! You're absolutely right about the lack of glossy reflections and darkness near the shore. It crossed my mind to try it, but the idea of trying to find a solution to masking the stone reflections from the underwater surface quickly made me think I'd rather spend my time on something else :P
As you can read above the primary reason to render this with PT is not the shadow detail, but the volumetric scattering of the water. I think water looks much nicer in PT, pity it's slow.

WAS

Quote from: Tangled-Universe on January 14, 2021, 11:16:46 amDoes that setup really require PT rendering?
Actually, probably not, as I'd imagine if you'd really want to use it, you'd want to highlight it so you'd want a more reflective angle to see the turbulence and such easier.

Hannes

Quote from: Tangled-Universe on January 14, 2021, 11:16:46 amreason to render this with PT is not the shadow detail, but the volumetric scattering of the water
I see. I think I never tried it.

DocCharly65


Dune

Quote from: Tangled-Universe on January 14, 2021, 11:16:46 amthe idea of trying to find a solution to masking the stone reflections from the underwater surface quickly made me think I'd rather spend my time on something else
It looks wonderful. Regarding the underwater reflections; it must be possible to convert the water altitude in every frame to an altitude mask for the 'planet line' of  nodes.

Tangled-Universe

I'm not so sure whether if that's possible Ulco. A long time ago I tried, but failed.
Just tried again for 15 minutes or so and I don't see how I can circumvent the inherent obstacle that TG uses one principle 'planet line' of nodes for these kind of things.
Then we didn't have access to conversions to world space, but I didn't get it to work.
(I think it has to do with that TG actually parses the network from bottom up and thus it can't be agnostic for multiple object's coordinates).
Kudos to you if you know how, I'd be happy to learn!

WAS

Perhaps this is something that Terragen should have an option for for volumetrics. A disable reflection rays for shaders within volume sort of feature.

WAS

January 15, 2021, 09:57:46 pm #11 Last Edit: January 16, 2021, 01:51:06 am by WAS
Also you'd think you'd be able to limit alt the same alt as the plane/sphere with a distribution node, and then warp it back up by the water displacement at the same amplitude, but it doesn't align right, and none of the transform settings will align it right that I can find.

Here is an exmaple of the issue. The displacement is inverted to follow the water level, but it seems like some of the secondary mixed noise is not read correctly or is inverted because of using -1 disp (or complement scalar) which then makes the fine details of the water out of sync. Or so it looks. Maybe @Matt  can weigh in on why exactly it can't line up perfectly on the micro disp level. Edit: it aligns much better with PF noise based disp (not inverted), but still not perfect down to fine details of the disp. Follows the larger shapes easy tho.

Dune

I'll have a look at it. It's not really volumetrics, though, but just a thin sheet with a certain displacement. But I do agree a built in 'reflections off' for under 'water' would be cool, but maybe hard to implement.

WAS

Quote from: Dune on January 16, 2021, 01:39:46 amI'll have a look at it. It's not really volumetrics, though, but just a thin sheet with a certain displacement. But I do agree a built in 'reflections off' for under 'water' would be cool, but maybe hard to implement.
Pretty sure PT adds volumetrics to water doesnt it? Approximated for speed, but there, refractions in shadows too if on a object. I dont know how its all setup but i imagine using the shader as a key you could be able to flag and cull any reflection rays from other stuff. Also probably best to have it selectable from a reflection shader itself so if you wanted you could still have reflections like specularless mirror surfaces.

Dune

Water is not like clouds, with particles, but just an infinitely thin sheet, like the planet. IMO the 'depth' is just a calculation, not 'real'.