# Some DOPs RnD

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I thought I'd make a topic here to share some RnD I've been doing in spare time in case it's helpful to anyone, as I've been able to learn so much useful knowledge from others on here. I have a couple of other scenes underway that I'll put up once they're ready. They're not for any particular shot, more just the result of one thing leading to another...

The first one is essentially a simple cloth sim a driven by an RBD sim, where some balls are attracted to a wandering point. I used a technique similar to generating a wet map to transfer some colour between the balls while they're touching which sort-of worked but ended up producing a lot more blue than anything else. Also for each point on the surface I calculate the difference between the average distance to neighbouring points during the animation and at the beginning, a sort of compression or stretch attribute and I'm using that to displace the surface first in SOPs, then also in the shader.

Edited by j00ey
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beautifull render ! and thanks for the breackdown!

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Thanks! I love the stuff you've been posting on here too - fantastic work!

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Here's another experiment from a while ago, never got round to putting it up at the time.

It never quite worked as I hoped it would - maybe I'll revisit it some time and somethihg better will come of it.

It's quite a simple idea - run a flip sim of whatever sort and sample the velocity of a 2D slice onto a grid of points. Then in COPs, starting with an image consisting of 0 to 1 horizontal & vertical gradients in the red and green channels [representing u and v], look up the velocities and advect the uv. On the next frame, read in the advected image and repeat. This image sequence is then read back onto a grid and used as its uv.

I started with an image of some pebbles, I wanted to smear them around with the velocity of the FLIP sim but the shapes were already quite blobby and amorphous so the effect was too subtle. Had I run the sim for many more frames they it might have worked btter but I decided to switch to some more geometric shapes.

As I said it never really went anywhere but in case anyone's interested in the technique I thought I'd put it up...

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