Morphing Ink

[few_a_fx]

So I'm working on this new effects, having ink morph into an object. I just wanted to get some opinions and some suggestions. Here's a link to what I'm trying to achieve and what I have so far.

http://www.pond5.com/stock-video-footage/ink-water-fluid_2.html

http://www.afughanimations.blogspot.com/

I read the forum topic that was post several months ago about ink and water, I plan on advecting the fluid to pops. Two question: 1.)how can I have an RBD object affect the motion of smoke(like something pushing through the smoke)?

2.)Whats the best way to create an ink shader in VEX(just starting to use VEX)?

here's the forum link I mentioned

http://forums.odforce.net/index.php?showtopic=8332&st=0&p=55443&hl=ink%20in%20water&fromsearch=1entry55443

Comp 1_2.mov

[pclaes]

There is some good info in this thread on using goal object for fluids, but it will require you to add and modify a bit of data in dops:

http://www.sidefx.com/index.php?option=com_forum&Itemid=172&page=viewtopic&t=14844&highlight=bullet

[few_a_fx]

thanks pclaes, I', reading the SIGGRAPH paper that was attached to this posting. I'll post an update as soon as I figure this out.

[few_a_fx]

Recent update on the motion for the ink in the water. Thanks anim for posting this file,

Wasn't for this post, but it ended up working for me. Anyways here's the link to see the recent update to this project. Any suggestions, ideas and tips are welcome.

http://afughanimations.blogspot.com/

[bandini]

Hi,

I noticed you referred back to a post I started on this topic. I checked out your tests and your breakdown. Looks like you are off to a good start.

In terms of rendering, I think you really only have two options. I experimented a lot and did not find volume-based shaders to work well at all for the look of ink. What will work are two different methods:

1. Lot of particles rendered as points with low opacity (very low opacity + millions of particles).

2. Less particles meshed using a particle fluid mesh.

In terms of the ink forming something, you can do this with a VOP pop if you are using advected particles. You need to create an attribute for the goal position then set the velocity of your advected particles to the goal position (goal position - advected position). You can factor in weight for the incoming velocity and drag as well. An important thing is to sort your particles and goal points in a way that will give you aesthetically pleasing results so that you do not have mush in the transition stage.

3D Buzz technical effects DVD has a really good example of doing particle goals that I would highly recommend checking out.

[few_a_fx]

1. Lot of particles rendered as points with low opacity (very low opacity + millions of particles).

2. Less particles meshed using a particle fluid mesh.

In terms of the ink forming something, you can do this with a VOP pop if you are using advected particles. You need to create an attribute for the goal position then set the velocity of your advected particles to the goal position (goal position - advected position). You can factor in weight for the incoming velocity and drag as well. An important thing is to sort your particles and goal points in a way that will give you aesthetically pleasing results so that you do not have mush in the transition stage.

Thanks bandini,

I think the particle rendering might be the one for me to use. As for the VOP pop will it work with an animated object? I'm planning to have a fish break through the ink, but you don't know its a fish until it breaks through and the particles morph or form into it. I also wanted to keep the ink following, so would it be better to have two similar popnets, or combine both the rendering options? Its been a slow week for me so I haven't had time to update, hoping to have a new post on Tuesday (just got 3D Buzz DVD - Python and Houdini Tools. been watching that). Thanks again.

---fughfx

[bandini]

Thanks bandini,

I think the particle rendering might be the one for me to use. As for the VOP pop will it work with an animated object? I'm planning to have a fish break through the ink, but you don't know its a fish until it breaks through and the particles morph or form into it. I also wanted to keep the ink following, so would it be better to have two similar popnets, or combine both the rendering options? Its been a slow week for me so I haven't had time to update, hoping to have a new post on Tuesday (just got 3D Buzz DVD - Python and Houdini Tools. been watching that). Thanks again.

---fughfx

You could probably do this with one popnet for the advected/targeting particles. You can scatter points on your animated fish as targets for the particles - it will work with an animated object. The trick with this method is getting the grouping/point assignments to work out and make something pretty. I have done a similar setup recently, but I can't show it due to NDA, unfortunately. Maybe once the project wraps...

Please keep us posted with the results. I am very much interested in this and would love to hear if you have any breakthroughs.

[few_a_fx]

Another update on this Ink Morphing project. This is just a video of the volume testing. I'm actually going to try something different with advecting particles, so this might not be the final look. Also remember this is just showing the motion or movement of the in;, nowhere near a final render, just a flipbook.

Here's a link to my blog so you can see the breakdown and process:

http://www.afughanimations.blogspot.com/

And here's a link to my ink reference:

http://www.pond5.com/index.php?page=search&p=0&q=ink+water+fluid&advs=

thanks

volume_test.mov

[few_a_fx]

So I found a free fish model (koi) and I just finished rigging it (not a very complex rig). I want to use the new motion fx to create a cycle where the fish swim slow to fast and back to slow. Does anyone one have any knowledge or expewrience with motion fx. I've been messing around with it for a while, but it doesn't look that appealing.

thanks

[few_a_fx]

Alright, So its been a while since I last posted an update on this WIP. October was a busy and crazy month for, did some freelance design stuff, sick for 2 weeks and ran into a rigging an animation problem. I've been going back an forth with procedural and key frame animation for the character (a fish). I finally decided on procedural since I'm not the greatest rigger, and my orginial rig and controls were terrible. I figured CHOPs would give me the control and motion I wanted, but this was my first time working in CHOPs. I was over thinking the process to much, and want to say thanks to Andy for pointing me in the right direction. Here's the link to the video and my blog to read up on the actual process (couldn't upload the video file to odforce for some reason). Please leave me any comments, tips or critiques here or on my blog.

http://afughanimations.blogspot.com/2009/11/ink-morph-swim-test.html

Thanks

jason