Waterfalls.... what on earth

[stelees]

Hey there,

So this is actually starting to break me, I just don't know what to change to make this ok. This render is 38mil particles, the height of the fall is about 8m.

Particle Shader - Points and pretty much all the defaults
Foam Shader - Bubbles, .6 size multiplier
Mist Shader - Points and the rest are the defaults

and it looks awful.

I would really love for someone to outline what it takes to come up with an actual decent waterfall using Phoenix.. please.

S.

[stelees]

If there is anyone looking at this, here is what I am trying to achieve..

https://www.youtube.com/watch?v=7geRWxf-8IM

No random flying particles.. just nice long flowing long strips of water but as you can see there are clumps / patterns in the foam / splash. Mine always just seems to disintegrate into 100000 particles.

[wxyz]

motion blur?

[waaazoo]

do you have a liquid mesh ? can you show the preview (mesh only, particles only, splash only, foam only, mist only ) ?
do you have some B2B ?

[fixeighted]

I've been playing around with this for a few hours (not including the boring sim hours) and have something like the defined strings you are looking for, I think.
The geometry is causing those and so it can be more refined to get a similar effect as the link you posted.
Although, looking specifically at those real falls it appears more that the water is going over the edge with only a little obstruction vertically below, so creating fewer outward splashes and falling actually more like a shower - at least to my eyes.
In my version I've avoided using bubbles completely, as the render time just shoots up and they don't look good anyway. So using points for mist/splash and foam seems to do the trick. Could probably omit one of those too.
I'll rebuild the geometry and refine it and see if I can more exactly match that reference next weekend if I get a chance.
You're welcome to the scene if it'll help
Additionally, I did not use the waterfall preset as I actually was not getting anything like the expected result and its setup looked odd to me (sorry dev geniuses ). Working in cms, when I add it it creates an enormous grid box, the bottom of which is way below z 0.0, which seems odd. Also the scene scale is not 1.0 which I expected it to be. I'm sure there are reasons for this but I could not get it to work right so I did my own

[stelees]

yeh that looks way better than mine... the scene would be AMAZING. I keep going back to this https://vimeo.com/273417990 Scanline - Black Panther breakdown. Getting the waterfall over the line is the start of some things I want to try.. but I have to get to that point first.

Also in relation to motion blur, yeh I have that one also.

Cheers indeed

[fixeighted]

I'll sort out a scene for you in a couple of days.
I had not seen that break-down before but just glancing at the the first bit seems to indicate that they use constraint volumes for the particles.
That is, a few seconds in you can see the shaped geometry of the falls - presumably to keep the particles from any weird flyout behavior (someone correct me if that sounds wrong).
I reckon that this kind thing is a case of maybe not relying entirely on real-life settings, but artistically using possibly increased gravity and other tricks to force the particles into doing what you need them to do
Iterating this stuff is so massively time-consuming but it now has me quite keen to dive into it (pun intended )
If anyone else has any 'don't do's' or other tips/insights then fire away!

[stelees]

ah man I have so many dud scenes of waterfalls and the time to render a few frames to just come to the realisation it's a dud. Scanline have a very cool Tomb Raider break down also and again, what they have is just so amazing to look at. You can see when the water comes over the edge there are clumps of splashes and foam that then just stretch out with the fall. My new attempt is filling a'pool' sort of deal at the top of the waterfall and then let that overflow and then form the river part to go over the edge... maybe it is a fine line between the velocity of the emitter so take velocity out of the equation completely and let gravity do them work.. I am bumbling through setting up a top emitter to fill a volume to over flow into a second grid (cascade) and then let that flow on over the edge.. dunno.. will just keep killing my electricity bill trying to get this one!

[fixeighted]

Here is a quick scene to play with. I hope it helps To get some water going over the edge is tweaked with the 'affect particles' parameter'. This is of course affected directly by what sort of scale your scene is literally.
The default values I believe are sort of physically correct, based on the liquid to splashes/mist then back to liquid diagram that was shared from the docs.
The 'strings' you were hoping for can be accentuated by the 'liquid-like' parameter.
Don't worry about Scanline. They have a load of people who've been doing this stuff for years and have their workflows sorted - plus they just might have a bit more processing power to iterate with
Particles are time-consuming for sure but a lot is to do with simply learning which parameters do what and gradually building on that knowledge. Plus spending increasingly large piles of cash on super-quick tech lol
To answer your other post about comping; render the liquid only, with the other shaders hidden, then simply hide everything and render each single unhidden shader separately.
https://www.dropbox.com/s/c7280xm6wv...0TEST.max?dl=0

EDIT: I meant to add that when you render, don't leave it unclamped. Clamp it to something like 5 or play with it until there's definition, but not massive overbrights, and it'll render quicker based on default settings in that file.

[stelees]

Thanks mate, already ripping into this and see what I can see. Scanline.. yes to all you said.. but an amazing benchmark to aim at.. even as a lame hobbyist!

Also.. what do you mean clamp to 5?

Will try this tomorrow, as soon as it comes up with the first shader dialog box max crashes.. will look at it when I am less tired.

[fixeighted]

Clamp is in colour mapping rollout

Re. crashes, make sure you're simming to your folders, not the ones that effectively point to my drives So change the output folders etc. and the save location of the cached frames.
Or just recreate the scene and copy/paste values.

[georgi.zhekov]

Thanks a lot for the scene - we have reproduced the crash in here as well and I hope we'll have a fix soon.

Somehow the simulator node got picked in the Particle shader instead of the corresponding particle system (probably an old scene may be).

In order for the scene to work correctly - go to each Particle shader and remove the simulator from the Particle systems. Then press the add button and select the simulator again - this will prompt you to pick the corresponding particle system.

Hope this helps!

[fixeighted]

Oddly, this is my scene and it was working perfectly when I sent it this morning....weird.

[fixeighted]

So this is my initial test to see how things were looking. Generally I'm pleased with this as it is only the splashes rendered, which I did for the sake of speed. It's 76mil parts.
Pretty much the only issue I can see is the diagonal banding on the vertical fall. What is causing this?

https://www.dropbox.com/s/ifdui6f088...UENCE.mov?dl=0

[georgi.zhekov]

Just wanted to let you know that we fixed the crash in today's nightly so using a build from today should work fine. The problem was when the Simulator was picker directly in the Particle Shader instead of a specific group.
The crash was introduced quite recently so if you were using an older build of Phoenix, there was no problem there.

As for the diagonal banding you're talking about - from what I can see in the video - it looks like shadow from the sun. Does it change if you change the sun's direction?