Page 2 of 2

Re: Underwater Caustic Effects with Perlin Noise

Posted: 08 Jan 2020, 16:13
by Cardin Collins
That looks doable. The tricky part, I think, is getting the right combination of turbulence pattern and displacement settings but I think you should be able to achieve the effect you want...

The way I would approach it would be to first create the turbulence using perlin noise or plasma on its own layer. Set it to invisible.

Then, on a duplicate layer of the actual animation clip to be distorted, use Displacement Mapping (under Distortion)and set the Source as the turbulence layer that you created. Since the turbulence layer is hidden, only its effects on the animation will be visible.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 08 Jan 2020, 17:17
by D.T. Nethery
Cardin Collins wrote:
08 Jan 2020, 16:13

The way I would approach it would be to first create the turbulence using perlin noise or plasma on its own layer. Set it to invisible.

Then, on a duplicate layer of the actual animation clip to be distorted, use Displacement Mapping (under Distortion)and set the Source as the turbulence layer that you created. Since the turbulence layer is hidden, only its effects on the animation will be visible.
Thank you, thank you ! I had missed the step to set the turbulence layer to invisible (inactive). If I get a successful test I'll post it . (the actual project I want to use this effect on is under NDA , so I can't show it , but I will make tests first , which are shareable . I'll try to remember to document each step I take ... I'm not good about doing that , so sometimes I achieve a good effect by trial & error , then if I have to reproduce the same effect six months late I forgot exactly how I did it ... :oops: )

------

UPDATE: Yes, this works. Created the turbulence on it's own layer , then used the perlin noise turbulence as the Source in Displacement Mapping applied to a layer.

Image

------

Here's a second test. This time I did not use Perlin Noise , I used a photo of an actual piece of ripple glass. I had it move across screen from right to left (using KeyFramer) then used it as Source layer in Displacement Mapping applied to the BG layer.

Image

Re: Underwater Caustic Effects with Perlin Noise

Posted: 11 Jan 2020, 19:58
by D.T. Nethery
Svengali wrote:
08 Jan 2020, 15:59
David,
You might get something like what you want from the OpticalFlowDeform FX.
sven
Thanks for that suggestion. I'm going to try that next.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 19 Jan 2020, 14:48
by Cardin Collins
Looks convincing to me :wink:

With just a few adjustments, the same method you used could also simulate heat haze for extremely hot temperatures in a blazing fire, desert scene, jet engine afterburners, etc.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 19 Jan 2020, 19:03
by D.T. Nethery
D.T. Nethery wrote:
11 Jan 2020, 19:58
Svengali wrote:
08 Jan 2020, 15:59
David,
You might get something like what you want from the OpticalFlowDeform FX.
sven
Thanks for that suggestion. I'm going to try that next.
The Perlin Noise or the ripple glass texture (used with Displacement Mapping) worked for my purposes. I can't get the Optical Flow to work for a rippling/wavy effect... I don't understand it. It seems to be one of those FX (like Inlay Texture) which uses a lot of CPU and/or RAM (?) and makes my computer go very slow. I could barely move my cursor without the "spinning beach ball" coming on for two minutes . If anyone who has faster computer would care to make a tutorial on how to use Optical Flow for a ripple/wave effect as shown above , I'm curious about how it might look.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 19 Jan 2020, 20:56
by Cardin Collins
D.T. Nethery wrote:
19 Jan 2020, 19:03

The Perlin Noise or the ripple glass texture (used with Displacement Mapping) worked for my purposes. I can't get the Optical Flow to work for a rippling/wavy effect... I don't understand it. It seems to be one of those FX (like Inlay Texture) which uses a lot of CPU and/or RAM (?) and makes my computer go very slow. I could barely move my cursor without the "spinning beach ball" coming on for two minutes . If anyone who has faster computer would care to make a tutorial on how to use Optical Flow for a ripple/wave effect as shown above , I'm curious about how it might look.
Sorry if you already experimented with this, but did you try the Random feature of Optical Flow?

Under the Edit Tab, there is an icon with two crossing arrows. It will set the vector fields randomly as you scrub along the timeline creating a wave/ripple effect. You can adjust the magnitude of the distortion (length) and variance until it feels right. Not sure how to adjust the speed of the distortion except by increasing the exposure of the frames, but this made things a bit choppy. Hopefully, someone with more experience will offer some more insight, as I'm curious too.

Like your system, My computer slows down on some of these fx as well. I usually test things out on a lower res duplicate project which helps out with rendering speed. Then I import the fx stack into the original project. Except when the parameters are resolution dependent, this works out most of the time.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 19 Jan 2020, 21:54
by D.T. Nethery
Cardin Collins wrote:
19 Jan 2020, 20:56
D.T. Nethery wrote:
19 Jan 2020, 19:03

The Perlin Noise or the ripple glass texture (used with Displacement Mapping) worked for my purposes. I can't get the Optical Flow to work for a rippling/wavy effect... I don't understand it. It seems to be one of those FX (like Inlay Texture) which uses a lot of CPU and/or RAM (?) and makes my computer go very slow. I could barely move my cursor without the "spinning beach ball" coming on for two minutes . If anyone who has faster computer would care to make a tutorial on how to use Optical Flow for a ripple/wave effect as shown above , I'm curious about how it might look.
Sorry if you already experimented with this, but did you try the Random feature of Optical Flow?
I have not tried Random. I'll give it a try.
Cardin Collins wrote:
19 Jan 2020, 20:56
I usually test things out on a lower res duplicate project which helps out with rendering speed. Then I import the fx stack into the original project. Except when the parameters are resolution dependent, this works out most of the time.
That's a good idea. I will also try that. Thanks.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 20 Jan 2020, 19:43
by Svengali
David,
I posted an OpticalFlowDeform tutorial in a new thread so more people might see it.

sven

Re: Underwater Caustic Effects with Perlin Noise

Posted: 20 Jan 2020, 20:47
by slowtiger
The funny thing about this "underwater effect" is that you don't see that in nature while underwater. The "underwater ripple" is a film convention, like a speed line in comics. So I'd be totally happy with just a ripple glass being moved across the screen, mimicking the age old effect.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 06 Mar 2020, 20:11
by D.T. Nethery
Cardin Collins wrote:
19 Jan 2020, 20:56
I usually test things out on a lower res duplicate project which helps out with rendering speed. Then I import the fx stack into the original project. Except when the parameters are resolution dependent, this works out most of the time.
Yes, the problem I run into when I try to test out a "heavy" FX (such as Warp Grid or Multiplane Camera) on a lower-res. duplicate is that the FX Stack parameters don't work when I import the FX Stack into the original (larger) project .

I just posted a Feature Improvement Request asking if someone knows how to write a script that will handle this task automatically.
See here: Need a script to Resize Multiplane Camera project .

EDIT: although from the replies I received in that topic it is apparently not possible with current George scripting .



.

Re: Underwater Caustic Effects with Perlin Noise

Posted: 15 Mar 2020, 10:23
by CartoonMonkey
This is beautiful water stuff!
Can anyone think of a way to seamlessly tile it? For use in a video game for example?
C

Re: Underwater Caustic Effects with Perlin Noise

Posted: 15 Mar 2020, 11:41
by slowtiger
Hm, tiling a replacement map? We did something like this by hand (and on paper) in 1995 for "Asterix Conquers America", of course I don't have those drawings now (studio property), but it's totally doable.