Do you want somemone to melt standing up or just kind of rippling in water?

You can always try adding effects (PD has some effects in there effects room that might work) and using a custom mask.

I'll try and make a video trying this effect.

There are several ways to accomplish this. Could you be more specific as to exactly what style of melting you want? Saving the world, one goofy video and meme at a time.

If you want a person or object, in video form, to melt, the best way would be to start with a green or blue screen to isolate the subject. You can then apply any number of effects to mimic the melt.
You've got some work to do a truly convincing video, but it can be done.
As Kevin asks, what are the specifics? HP Envy Phoenix/4thGen i7-4770(4@3.4GHz~turbo>3.9)
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I was going to do a "basic" video of someone standing on a sidewalk and melting into goo while having a conversation with someone. I looked into the standard Effects in pd9, but the closest thing they have is Fire and Huge Fire.
Thanks for the help!

I'm thinking maybe a ripple effect in a separate clip, then using a motion path downward in a clip and laying that all on top of the original clip. It might work! I'll test this theory after lunch today. Saving the world, one goofy video and meme at a time.

I'm not sure that $10,000 software could do that without a green-screen. You might have a lot of fun trying, and screens are not that expensive.
You video your non-melting scenes or background, including the person pretending to have that conversation.
Then you video the melter, or meltee...in front of a blue or green screen, also pretending to have that conversation.
See where I'm going?
You don't really HAVE to use a screen, you could paint a wall.
HP Envy Phoenix/4thGen i7-4770(4@3.4GHz~turbo>3.9)
Nvidia GTX 960(4GB)/16GB DDR3/
Canon Vixia HV30/HF-M40/HF-M41/HF-G20/Olympus E-PL5.
Tape capture using 6 VCR, TBC-1000, Elite BVP4+, Sony D8 camcorder with TBC.
https://www.facebook.com/BarryAFTT

I got varying degrees of success, but nothing like what a green screen would do. I had to resort to still image pictures for background with a ripple effect, then cropping my subject video and applying chroma key, then PiP manipulation( I'm using PD8 for this), then adding the video. Then trying to save that and cover over the original scene. It's just not the same.
Barry knows his stuff and if he says it's not gonna work, you can believe it. I just wanted to try a workaround idea, but I'd not be happy with it in my videos either. Saving the world, one goofy video and meme at a time.

You guys are awesome! You have me a ton of ideas and you saved me some $$ on a green screen!
-Cheers!

So, you're not going to get a screen? You can buy a screen with a frame-stand for $150.00, maybe less, lotsa fun!
HP Envy Phoenix/4thGen i7-4770(4@3.4GHz~turbo>3.9)
Nvidia GTX 960(4GB)/16GB DDR3/
Canon Vixia HV30/HF-M40/HF-M41/HF-G20/Olympus E-PL5.
Tape capture using 6 VCR, TBC-1000, Elite BVP4+, Sony D8 camcorder with TBC.
https://www.facebook.com/BarryAFTT

I agree with Barry and Kevin. It would be best with a Green Screen. Because other wise youll have to use a still image and with that the effect dosn't look as good.

Ofcourse you could also do it with a custom mask on a video with the effect applied to it. But because its a mask youll have to change shots each time you want the subject to move positions.

For example you could do a wide shot with the subject standing still and screaming that they're starting to melt. (The custom mask would only effect the person. Just put that in track 2 and the same im track 1 with the inverse of that mask.) then switch to an overhead shot and use a resized image to show a distored melted person. Have a png of just this image on a shot of the ground with out this.

For the video of shot 1 you could use a water flow or some sort of triangle stretch effect. And you could use a water ripple effect for the image in the second shot.

Take a look at this!

http://youtu.be/MhYpssoRBgY

It's not perfect, but I only worked on it for a minute. Green-screen, fun.

HP Envy Phoenix/4thGen i7-4770(4@3.4GHz~turbo>3.9)
Nvidia GTX 960(4GB)/16GB DDR3/
Canon Vixia HV30/HF-M40/HF-M41/HF-G20/Olympus E-PL5.
Tape capture using 6 VCR, TBC-1000, Elite BVP4+, Sony D8 camcorder with TBC.
https://www.facebook.com/BarryAFTT

Cool stuff Barry! Do you think you could make a "pool" of goo on the floor after she melts?

BTW, Barry, not sure if I'll buy the screen or not. I have to make sure that I can get enough use out of it. Painting a wall green sounds like a more economical solution and less set up!

Pool of Goo? Isn't that a rock band?
Yeah, you could do that.
You can steal effects from other places and use them, just use chroma-key to remove the surrounding "frame".
Check your PM for a site that has loads of stuff you can use. HP Envy Phoenix/4thGen i7-4770(4@3.4GHz~turbo>3.9)
Nvidia GTX 960(4GB)/16GB DDR3/
Canon Vixia HV30/HF-M40/HF-M41/HF-G20/Olympus E-PL5.
Tape capture using 6 VCR, TBC-1000, Elite BVP4+, Sony D8 camcorder with TBC.
https://www.facebook.com/BarryAFTT

Gotcha! thx.

I've not searched for that in particular, but you may check the DirectorZone for "effects" that look like that. Just a thought. Saving the world, one goofy video and meme at a time.