Reducing Stretch and Bounce in Grain Ropes

[DeeLan]

I'm having a play with grains for making simple ropes and cables, and the problem I'm having is that they just bounce and stretch waaaaaaaaay to much! The rest length attribute on each prim is the exact length of those prims (and therefore the sum of all the rest lengths is the length of the rope) and the substeps on the pop solver are set to 10. What I want to do is simply reduce the amount that the rope stretches and bounces. Up till now, the only real solution I've found (and seen other people do), is mess around with forces and substeps (in one case I turned them up to 1000), but doing it that way just feels so convoluted and still doesn't let me tune in the exact results that I want. I've also been playing around with attributes as well as having a dig around in the solver itself to see if there is anyway to modify it, but alas I have come up with nothing (I'm struggling to figure out whats going on the grains node).

I guess what I'm wanting to do is find a way to control how the rope moves/looks (ie the stretching and bounciness) with physical properties instead of forces. In other words, instead of having to use a pop drags and all that, just get the rope to not be so susceptible to stretching in the first place. Does anyone have any ideas?

[mestela]

Apart from upping the number of iterations on the grain pop, I've found there's not much you can do. Faking ropes/cloth with constrained grains is a neat trick, but I keep my expectations very low. If the movement looks good, and is fast to sim, great, but if you want something more than the default bacon solver look, especially if you want to drive it with physically plausible settings, then you're back to rbd or wires.

Oh, should say that 'upping the iterations' means going silly high, like from the default of 10 to 100 or 200 to minimize stretching. If your sim can use opencl it can still solve pretty quickly.

 

 

[violalyu]

Hi Dylan,

From last time I did some stretchy thing with pop grain, since it is pop I tried "taming" it using pop drag, and it helped a little bit, also you can write in a pop wrangle where you force the velocity to go low once it reach some high value, hope this helps!

[DeeLan]

Thanks for the tips guys  Also found that reducing the Rest Length helps a bit (just a little). Probably should have though of that sooner but oh well