Author Topic: shadow but no shadow  (Read 1871 times)

Offline Tangled-Universe

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Re: shadow but no shadow
« Reply #15 on: February 03, 2017, 03:56:44 PM »
Could you upload a simplified version of your setup? Just the water, 2 atmospheres and camera?
I think you're right about my mistake, but I'd like to try and see if I can help out somehow.

The dark bands are possibly a meniscus effect or where light is actually being refracted away from the camera, thus causing black bands.

Offline Dune

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Re: shadow but no shadow
« Reply #16 on: February 03, 2017, 04:17:04 PM »
I'll do that tomorrow, am just about to quit for dinner. Thanks, Martin.

Last for today (am I sounding familiar?), still no good.

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Offline N-drju

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Re: shadow but no shadow
« Reply #17 on: February 03, 2017, 04:38:34 PM »
Could you upload a simplified version of your setup? Just the water, 2 atmospheres and camera?

That would be useful no doubt. I think that the last picture for today doesn't quite make the cut indeed. :( All rays are gone. Shadows not very visible either.

_______________________________________

I just realized that you obviously cannot pull off that trick with thick object population... objects do not have the "visible to other rays" option either. Damn!
« Last Edit: February 03, 2017, 04:46:58 PM by N-drju »
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Offline zaxxon

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Re: shadow but no shadow
« Reply #18 on: February 04, 2017, 05:51:07 AM »
Caustics in TG would be wonderful! Or at least some kind of good 'fake'. I think you've covered some of the aspects of the problem, and maybe there is no solution. Nice experiments regardless.

I put the trout model and the maps up in the File Sharing area here for anyone who wants them.

Offline Dune

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Re: shadow but no shadow
« Reply #19 on: February 04, 2017, 06:44:15 AM »
That's a cool gesture of you, Doug.

I've just thought of something else, but that wouldn't throw the light on all ground stuff and there's another problem. It's possible to convert the wave displacement to a mask, after stretching it in Y and rotating by the sun's angle, that could work as a mask for additional illuminated cloud, hence 'rays'. But the origin wouldn't stay the same after rotating, so there's a problem.

I don't know how it would work on an exact copy of the water layer (some masking function added of course) with an invisible setting, but visible to other rays. Would that still throw a shadow in the water? Being exactly where the water plane is you wouldn't have reflection or shadows on top. You'd only need to tell the cloud to receive shadows from surfaces. But the water plane has shadows turned off, for obvious reasons, so that may not work.
And increasing lighness of the shadows parts to the needed value for 'normal' light would make the 'beams' and caustics light up, relatively. I'll try something like that later and upload a file.
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Offline bobbystahr

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Re: shadow but no shadow
« Reply #20 on: February 04, 2017, 07:37:10 AM »
Have you looked at the caustic generator program, there's a paid for version (55) and a free one (with typical limitations)
You could use this to control the volume of a cloud layer. Micht do the trick with some fiddling ...

Paid version
https://www.dualheights.se/caustics/

free version
http://www.softpedia.com/get/Multimedia/Graphic/Graphic-Others/Caustics-Generator.shtml

whew, if y want the 64 bit  "pro" version it jumps to 180 EUR...think I'll stay amateur
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Offline bobbystahr

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Re: shadow but no shadow
« Reply #21 on: February 04, 2017, 07:37:57 AM »
Caustics in TG would be wonderful! Or at least some kind of good 'fake'. I think you've covered some of the aspects of the problem, and maybe there is no solution. Nice experiments regardless.

I put the trout model and the maps up in the File Sharing area here for anyone who wants them.

Heading ther now, thanks Doug...
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something Blue.
Ring out the Old.
Bring in the New

bobbystahr

Offline Dune

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Re: shadow but no shadow
« Reply #22 on: February 04, 2017, 07:53:41 AM »
Here's a basic working file. The extra plane+shadow idea doesn't work, as far as I can tell.
The idea is of course to have the shadows/lights of the 'caustics' on all surfaces and cloudmurk except the water plane, also have the stuff above water partly visible through the water and the reflections of fish or whatever on the underside of the water plane, like in some of these references. Tough cooky.
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Offline Kadri

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Re: shadow but no shadow
« Reply #23 on: February 04, 2017, 11:49:22 AM »

Had a look at your file Ulco.
Finding what you want looked harder.
I just saw that you could use the aurora kind of method to the cloud in the underwater and get rid of the shadow file over water.
One bad thing are the angles. But a metacloud approach could be used for that problem.



Offline Dune

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Re: shadow but no shadow
« Reply #24 on: February 05, 2017, 07:42:10 AM »
You can tilt the aurora, but I prefer a method with shadows instead of just lighting the cloud, so it will influence all light underwater, not just the cloud/murk. With a water shader or a single sided glass or even just a reflective shader it's easy to get something nice, but then you don't see anything above water.
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Offline Dune

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Re: shadow but no shadow
« Reply #25 on: February 05, 2017, 01:22:55 PM »
RDM is at 1, glass shader in front area, reflective more distant. Just the shadow cloud for the 'caustics'.
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Offline zaxxon

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Re: shadow but no shadow
« Reply #26 on: February 05, 2017, 02:33:50 PM »
They are both brilliant Ulco! The underwater scene works better in my opinion, but the the second definitely shows promise for the technique. The vegetation both under and above is also fantastic!

Offline Dune

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Re: shadow but no shadow
« Reply #27 on: February 05, 2017, 03:17:54 PM »
Thanks, Doug. I bent your trout a bit in ZBrush to get another posture, btw. You may have noticed.
In case you still haven't seen enough of my work: www.ulco-art.nl

Offline zaxxon

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Re: shadow but no shadow
« Reply #28 on: February 05, 2017, 05:28:43 PM »
Bend away! I originally had made several 'bent' variations as morph targets as well. I should probably tweak the mouth area of the map a bit as the trout were never meant for some of the close-up poses you've used. It's pretty exciting to see some form of caustics for underwater scenes in TG . Genius use of TG again!
« Last Edit: February 05, 2017, 05:31:37 PM by zaxxon »

Offline KyL

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Re: shadow but no shadow
« Reply #29 on: February 07, 2017, 05:16:40 AM »
very nice render Ulco. I would go a bit more murky but it's quiet nice already.

One cool thing to add could be the chromatic aberration in the caustics to fake the light diffraction. Maybe it's as simple as shifting the r,g and b channel in the map you use!

Cheers!