Water pouring

Show us your Realflow WIPs
shaun_michael
Posts: 4766
Joined: Sun Sep 10, 2006 8:04 am

Water pouring

Postby shaun_michael » Tue Jan 09, 2007 12:01 am

I think I would up the res, pull the surface tension back to somewhere around 5, and give your lettering a little more bounce. I'm guessing you'd rather see some violent interaction when it hits the lettering? By dropping the surface tension you'll give the particles a little more freedom to break apart, but you'll need the resolution to do it (and to prevent the tearing you're seeing).

Have you tried running a number of low-res sims with differing random factors in the emitter then combining them all in a binary emitter? Sometimes its a little quicker to reach the res you want. Also, if you dont mind me saying, the edges of the flow look a little too uniform, and need a little more detail, which can only be achieved with a lower particle radius and blend setting in the mesh - which can only really be achieved with a higher res sim.

Does the fluid have to interact with the rocky outcrop and base you have in any way? When you're simulating, are you simming with the ground layer in the sim? If you're only going to see this shot from the sort of angle you've shown it might speed things up to remove that from the simulation, add a kill volume daemon to take the stray "lower" particles away, simulate it vertically (if you're not already), and add your ground layer in later. I mean if there's no significant geometry that the fluid has to interact on your ground plane other than the lettering, take it out. I cant remember if that's what you said you were doing already - just throwing about ideas.

It's getting there though for sure but I would go more for the "fluid filmed at normal speed then slowed", rather than the "high-speed photography, non-motion blurred" look. A little motion blur would add a sense of it's speed, and some splash particles (either rf simmed, or in your 3d app) would start to add the sense of realism you're after.

Then its just a case of being careful with your texturing.

Keep going Ruben, it's looking better each time.

Shaun


Ruben
Posts: 7
Joined: Mon Jan 01, 2007 6:56 pm

Water pouring

Postby Ruben » Wed Jan 10, 2007 12:36 pm

I changed the resolution up to 20, decreased the surface tension to 5 and increased the bounce in the letters (thanks Shaun!). Also increased the speed to 5.0 in order to get rid of those horrible holes in the mesh (thanks dalo!). So here is a quick render with the new settings:

New settings

I think it looks much nicer. It has a much more organic feel to it although I think its a little too chaotic. But I`ll be rendering a video in order to see it in action.

shaun_michael
Posts: 4766
Joined: Sun Sep 10, 2006 8:04 am

Water pouring

Postby shaun_michael » Wed Jan 10, 2007 7:39 pm

Looking good Ruben. Don't forget the motion blur, and if you have time get some dumb particles in there to add to the dynamism of the water/text collision.

Looking forward to seeing the vid soon.

Shaun

User avatar
brandony
Posts: 231
Joined: Sat Oct 21, 2006 7:38 am

Water pouring

Postby brandony » Wed Jan 10, 2007 8:30 pm

like shawn said add some dumb particles for some spray.. you wouldnt need much and i think the motion blur will add alot to it.. looking good!
Brandon Young
www.byvfx.com
FX Artist | TD

Ruben
Posts: 7
Joined: Mon Jan 01, 2007 6:56 pm

Water pouring

Postby Ruben » Thu Jan 11, 2007 1:14 pm

Ok, so I rendered a video and I think we`re getting somewhere :)

New video

I really like how it turned out. Finally I`m seing some water like motion in the mesh. Unfortunately,I`m only adding motion blur when I`m positive certain about the render, because I`m almost certain that it will triple the render time. Regarding the dumb particles I really dont know how to add that to the scene. Its like another emitter close to the emitter with the liquid particles? Another thing thats buggin me its the shaking in the mesh. Any sugestions? Thanks a lot for the help guys!

User avatar
dalo
Posts: 50
Joined: Fri Sep 15, 2006 4:16 pm
Contact:

Water pouring

Postby dalo » Thu Jan 11, 2007 2:19 pm

hey ruben

i like that slomo look of it and since it looks like you are not pretending to have a real film camera, i am personally not sure, if a motion blur is that necessary(in sports and scientific photography they even try to reduce motion blur with a lot of effort, your mesh is nice, so why hide it by blurring?). i might be wrong as well, its just a different perspective.
but anyway, you should give it a try. its possible that your mesh flickering might be less obvious with motion blur turned on.
what renderer do you use? with scanline(in max) there is the nice thing called image motion blur(a post processing effect which is put on top after the rendering by max).
it is less correct but fast for a preview purpose.
that flickering seems to be a topic itself, i read it before in this forum:
http://www.realflowforum.com/view_topic.php?id=274
i encountered that as well and up to now i only tried to workaround it, but never got rid of it completely.
i think in that case i resimulated with more particles for other reasons as well and it got better. i am not sure, if thats really a solution.
there must be a way improving it in the mesh settings, resolution maybe?
i would like to know myself....:)

shaun_michael
Posts: 4766
Joined: Sun Sep 10, 2006 8:04 am

Water pouring

Postby shaun_michael » Thu Jan 11, 2007 4:07 pm

Dalo's right of course, you dont "need" it. It all bolis down to what you want the finished piece to convey. Will motion blur help you to accomplish this, or not. My advice however would be to steer away from not adding it because your mesh looks nice - add it because your piece needs it, or dont because it doesn't.

Shaun

ps - just running a small test to see if I can come up with a cheap way of adding spray to your scene utilising what you already have. If all goes well I'll be back in a bit

shaun_michael
Posts: 4766
Joined: Sun Sep 10, 2006 8:04 am

Water pouring

Postby shaun_michael » Thu Jan 11, 2007 6:14 pm

OK, so there may well be a way of creating "spray" particles after a sim without using a script. The problem we face here is that we want the spray to bear a close relationship to the leading edge of your water, where the spray event will happen.

Here's what I did.

Ran a sim with a rectangular collision object (supposed to represent your text) and a low resolution emitter scaled to be the same size as the collision object (to represent your flow of fluid).

I ran the sim for the first time with the object inactive until I had about 5 or 6 frames of the sim, but I didn't allow the particles to collide with the object. (this would represent your initial sequence of simulated bin files.

I then deleted the emitter and activated the object.

I added a binary emitter and called up the sequence of 5 frames I just simmed.

I then added a K Collision daemon and set it to use the cube object and to have a birth rate of 5 - so that for each particle that collided with the object 5 more were produced.

In your case I would load the binary emitter with the sequence of bin files you have simmed but would set the release particle value to be about frame 5 - meaning that the sim would use the bin files already calculated up to the frame you have stipulated, then start calculating based on the binary emitters particle properties, but would not use more particle bin files from your original simulation. What we would have then would be the leading edge particles of your sim only.

I then adjusted the pressure settings in the binary emitter to be zero for both internal and external pressure. This, in effect, makes them dumb particles, but of course you could then just as easily use any pressure setting you wanted.

All I did then was run the sim again, making sure that I did not have my original emitter in the scene (I deleted it, but you cuold just as easily make it inactive, or deselect it in export central - the purpose of course is to ensure you dont overwrite your original sequence.

Now I have a set of bin files, where each partilcle is being multiplied by 5 each time it collides with hte object, giving me a mass of particles.

I can simply then create a new binary emitter and load my newly simmed spray particles into my scene if I want to mesh them, or even easier, take that sequence of files into my 3D app as simple particles and shade them there. For spray I only really need them to be sprites that turn transparent over time using a gradient shader, giving the illusion of a fine mist of spray.

I dont know how this would work for a full blown sim. It might be that the leading edge of your sim would arrive at collision before or after the binary loader version, but you can offset the frame at which particles loaded into LW appear so I wouldn't necessarily be a problem in my case.

I hope that makes sense :)

Shaun


Return to “Work in progress”

Who is online

Users browsing this forum: No registered users and 1 guest