Help Smooth jagged edges of ObiCloth

[PawleyBoboli]

Hi Folks,

Sorry for the newbie question.  I'm animating a logo in Unity with ObiCloth.  It's working as I would like, but the edges of the cloth are not smooth at the end of the animation, where I am stretching it over a sphere.  It has taken me a long time get the right combination of constraints and positioning, so that at the end of the animation, the "tarp" is positioned as the client wants it over the sphere.

Is there a parameter that controls how smooth the edge of the cloth will be? Or is there something in the Solver I should change?  Every time I tweak something, it seems to affect a lot of other things and I have often started over.  I pretty much have the elasticity and springiness I would like when the tarp is actually moving, but small parameter changes seem to affect it quite a bit.  Any help is appreciated.

The attached "mars logo question.png" (with star background) shows the final step of the animation in Unity.  The position and wrapping of the tarp is correct enough, it's just not smooth enough on the edges.  The client's logo is attached for reference (what I'm trying to accomplish).

Thanks for any info
--Kevin

[josemendez]

Hi Folks,

Sorry for the newbie question.  I'm animating a logo in Unity with ObiCloth.  It's working as I would like, but the edges of the cloth are not smooth at the end of the animation, where I am stretching it over a sphere.  It has taken me a long time get the right combination of constraints and positioning, so that at the end of the animation, the "tarp" is positioned as the client wants it over the sphere.

Is there a parameter that controls how smooth the edge of the cloth will be? Or is there something in the Solver I should change?  Every time I tweak something, it seems to affect a lot of other things and I have often started over.  I pretty much have the elasticity and springiness I would like when the tarp is actually moving, but small parameter changes seem to affect it quite a bit.  Any help is appreciated.

The attached "mars logo question.png" (with star background) shows the final step of the animation in Unity.  The position and wrapping of the tarp is correct enough, it's just not smooth enough on the edges.  The client's logo is attached for reference (what I'm trying to accomplish).

Thanks for any info
--Kevin

Hi!

This happens because the default update mode for distance constraints is Sequential. In Sequential mode, constraints are updated one after another, which results in biasing as the constraints updated last each frame have a stronger influence.

The solution is to switch to Parallel mode (under ObiSolver, distance and bend constraints). This mode however converges much more slowly (the cloth willl be stretchier) so I'd advise to use more substeps and iterations.

See:
http://obi.virtualmethodstudio.com/tutor...olver.html

Also this blog post, while a bit technical, can be useful to understand what's going on:
http://blog.virtualmethodstudio.com/2017...3-solvers/

[PawleyBoboli]

Hi!

This happens because the default update mode for distance constraints is Sequential. In Sequential mode, constraints are updated one after another, which results in biasing as the constraints updated last each frame have a stronger influence.

The solution is to switch to Parallel mode (under ObiSolver, distance and bend constraints). This mode however converges much more slowly (the cloth willl be stretchier) so I'd advise to use more substeps and iterations.

See:
http://obi.virtualmethodstudio.com/tutor...olver.html

Also this blog post, while a bit technical, can be useful to understand what's going on:
http://blog.virtualmethodstudio.com/2017...3-solvers/

Thanks tons, Jose.  It took a few tweaks to get the right combo of substeps and iterations, but it looks great now.  Your articles also helped my understanding of how to tweak it.  Thanks!

--Kevin
(final result png attached)