Creating a geo for a convincing looking cancer cell

[pfistar]

Hi all,

Relative noobie here, looking for general advice on how I might approach modeling a cancer cell that looks like this:
https://www.mskcc.org/sites/default/files/styles/width_800/public/node/167374/3x2/sciencesource_ss21694540_1200x800.jpg [www.mskcc.org]
or this:
https://static.independent.co.uk/s3fs-public/thumbnails/image/2016/02/15/21/1-t-cell-corbis.jpg?w968h681 [static.independent.co.uk]
One physical feature of the cell that I’d like to pull off convincingly is the sticky-looking tendrils that shoot out from the membrane, that look a bit like viscous liquid has been shot out from the surface of the cell. 

Though something like the image in the above links would be ideal, I would settle for something like this: 
https://lymphomanewstoday.com/wp-content/uploads/2018/09/shutterstock_565670083_zps0eglo9ri-1000x480.jpg [lymphomanewstoday.com]
I would want to avoid something like this (where the tendrils resemble veins, or maybe octopus tentacles:
https://www.segnidalcielo.it/wp-content/uploads/2017/08/GoldNanoparticles.jpg [www.segnidalcielo.it]

Since for now I only actually need a static model, my first inclination would be to start with a simple POP setup, have some particles explode off a spherical surface and append a trail SOP to get the tendril trails. I’d run the sim and use a single frame from it as the cancer cells base geo. This only gets me so far though, as there are other important visual details that I’ll refrain from talking about until I some experienced person can tell me that this is definitely the way to go.

My other inclination, which I realize might be inviting insanity, is to create a “fluid explosion”, using a FLIP setup with some velocity noise coming from the SOP level, and playing with DOP node settings to get the right kind of viscous/stringy effect from the particles. From there, again, I’d run the sim and use a single frame of geo for the base for my model. 
I’ve so far made an attempt at this (file attached), though have only tried seeing what I could get by using nothing but some noised-up velocity on the SOP source, some DOP gravity and tweaking settings in DOP Source Volume and Solver nodes, pertaining particularly to viscosity and surface tension (though I’m not sure the latter is relevant). I’m able to get some neat looking effects, but not really the ones I’m specifically after. 
What I’d wonder here is whether 

• this ‘explosion of viscous fluid with a very high tensile strength’ could even be achieved with a fluid sim, and if so, would I need to push/pull the “sticky/stringy” fluid outward by having the FLIP particles stick to a set of “collision” particles which are then launched outward, pulling some of the fluid along with it.
• Or, could this effect be achieved by simply applying velocity to a Fluid Source SOP with very low particle separation, and then relying on settings available in DOPs nodes to get the long / stretchy tendrils.

In any event, I’m certainly open to suggestions even if they’re completely different approaches to what I’ve described above. Thanks ahead of time to anyone responding!


Nik pF

CancerCell_FLIPFluidFromObject_v021.hipnc

Edited March 9, 2019 by pfistar

[tmdag]

just an idea you could explore:

 

cancer.hipnc

[pfistar]

Much appreciated tmdag!!! 

This is awesome!! I presume you built this network yourself?

I finished an extensive Houdini course not too long ago, which covered most vfx basics, but did not explore cloth and/or soft-body dynamics.

Before falling down into a tutorial rabbit-hole, I'd wonder if you'd have any suggestions to how I might approach making the tendril offshoots look like they sag a bit in the middle, as if they're made of soft material. My guess would be that it wouldn't be too hard to apply some physical properties and some forces to the linework geo before applying the PolyWire thickness, though i don't have much of an idea which SOPs and/or DOPs would be appropriate for such a thing. Could it be done with a simple WireSolver or would I more likely need to open Vellum for something like this?

Many thanks again!

NpF

 

 

 

[tmdag]

Not a problem, pleasure to help.

Yes, I've made that setup, feel free to use it.

 

As of 'sagging offshoots' - yes you could play around with simulations. I've created just a line (which later is meshed) but that line could be used in a simple wire solver.

You could also have full procedural approach - for eg. working in lines UV space. As U spans across an offshoot (from root to tip), you could displace points in -Y based on U, which could be done using a simple ramp.