Hello everyone, i want your help to decide if i have finally gone fully mad or if this is just a temporary *glitch* in my brain....:-S

My last gunge tank vids were good, but could've been better. The flow of the gunge wasn't quite what i wanted, blah blah blah.
So i've taken a long time (probably too long?) to think about what went wrong and how i can improve upon it. The answer? Animate real particles with the right texture, stickyness, consistency, etc. and see how it comes out through various objects (see example pic)
But i want to know if anyone else has taken things to this level or if they 'just get on with it and see how it turns out' - because i tried that last time and look what happened :ohbruther:

Anyway, advice please. Or should i just hold a vote on my current level of sanity? :dunce:

Thank you in advance!
Katie x

(p.s. the "object" in the pic is supposed to be a cat - i wanted to see what would happen if it got gunged! )

I consider it a project worthy of further study. We've been operating for some time on the assumption that gunge flow should mimic that of a domestic shower, but why? It's a hellaciously inefficient way to gunge a body, IMO, what with most of it unpredictably deflecting off to one side or the other if the stream is too powerful, etc. resulting in a flat-out waste of material.

I'd suggest a delivery system that delivers a gunging from multiple angles, at the very least - maybe even from the bottom up (Hey, it's where we're wired for the best reaction, after all).


Also, very nice cat; I had a dog like that once:

No you are not mad, well not unless I am as well ! I am always trying to find better ways to wam

Welcome back by the way ! x

Hey, if you have access to CFD software like that, go for it!

Thanks for your kind replies
It's nice to know i haven't gone crazy (yet) and will keep on playing with my particles since i don't have any balls to play with

And for anyone who is interested in what happened to the cat, see the attached pic...
(it drowned)

Katie x

Well, it all depends on what you want from your gunning. If I were building a gunge delivery system then I'd want laminar flow so as to ensure the stream went in the right direction. Beyond that I'd want to get the best balance of flow rate versus length of gunging. Finally, I'd be considering the coverage. Is a single stream to the head better than multiple streams aimed at different locations?

The problem with modelling it is that the viscosity is a bit of an unknown. I'd suggest running a sensitivity study to see what effect that has. The sensitivity to pipe friction will depend on the pipe diameter so larger pipes should prove less sensitive to this. Although I would expect that the shear through the fluid would be significantly higher than water due to the viscosity.

The biggest unknown is the target. Unless they present a uniform face in every case the results are likely to vary a lot. I'd think experimental testing would be more productive than modelling for this aspect.

Dave

Hi Dave thanks for your detailed response
I'm very fortunate in that i'm using 3D Studio Max for the physical objects and RealFlow for the particle physics. This is very handy because RealFlow lets me set the fluid interaction levels, surface texture and roughness on objects and fluids, and i can have multiple streams or direct one large flow through several 'tubes' before dropping onto the victim.
I don't want to say too much about my delivery system because i've put a lot of technical thought and work into it, and i've got it working perfectly now.
The length of flow from the 50ltr tank is just right and the gunge doesn't splatter everywhere.

Now about the fluid viscosity... This is something i've had to tweak an awful lot to get the particle size, density and interaction levels right, but then there's the surface tension to consider! :-S

Overall i think i'm heading down the right path with the modelling, and mixing gunge to the right viscosity won't be a problem - i've become quite good at it

However you are spot-on right that i need to make the digital tests become real tests. That will be the next step when i've tweaked everything and rendered it into a nice clear video with Maxwell Render

I'm not saying too much at this stage because i've had some of my ideas stolen before, but all will be revealed...

Katie x