nHair component to component constraints not holding when translated


#1

I have been creating a molecular assembly which is part of the DNA repair mechanism and have been rigging the long snaking structures, consisting of 2 intertwined chains on either side, joined at the top with a zinc hook (this forum will only let me post one image, unfortunately). I’ve used joint chains with ikSpline handles driven by nHair and the follicles locked to the base, leaving the coils free to wave about at the top. I have then used component to component constraints to constrain about 6 CVs from the output curves together, so that the two coils are attached to each other and then to the other two coils at the top, to give a roughly oval structure ie three constraints. This works nicely, with the desired organic animation. However, if I translate the rig, for example along a piece of DNA, the third constraint, which joins one set of two coils to the second set of two comes apart, and so therefore do the meshes (see attached image). I have tried changing the constraints to ‘weld’, which gives wildly erratic movement, setting the strength to 1,000, increasing the nucleus substeps, setting the nucleus start frame to 0 (which completely messed up the meshes), setting the nHair to ‘no stretch’, all to no avail. I’m not sure what else to do to try to make these meshes constrain to one another when being translated. Any suggestions are greatly appreciated.
Thanks so much in advance,
M


#2

I resolved this problem by keying on the nHair start curve attract attribute to a low value (0.01) when the rig is in motion and then keying it off again slowly once the rig has stopped moving. Seems to keep the component to component constraints together, whilst in motion.