Ropes and sails

Hi. I am kinda new to Blender and 3D animation in general so this is probably a very noob question:
I want to animate a square sail (as cloth) pinned along the top row of vertices (this i can do). I also want to tie down the lower corners using ‘ropes’ of a different material (maybe a cloth or soft body that stretches). What I want to know is how can I do this?

Thanks in advance.

Include the corners of the sail in your pinning group (possibly with a lower weight, depending on how rigid you want the attachment to the rope to be); at each corner add a hook to a new empty; and vertex parent each of those empties to the appropriate rope end. The sail corners will now be dragged by the rope ends.

Next do the same thing the other way round: at the end of each rope add a hook to a new empty, and vertex parent those to the sail corners. The rope ends will now be pulled by the sail corners.

I got this to work OK using cloth for the ropes as well as for the sail. I’d rather have the ropes as soft bodies, but I couldn’t get softbody ropes to follow the sail corners as cleanly. That may just be because I’m much more familiar with the cloth settings than with the softbody ones.

Best wishes,

Hi Mathew,

I have tried to follow your instructions but I end up with the following:
Any suggestions?


It looks like one end of the rope is floating free. Both ends need to be pinned (if cloth) or be in the goal group (if softbody): one at a fixed point, the other hooked to the sail.

Best wishes,

It looks to me like the hooks stay in the original place and do not move with the rope end and sail corner.
I have tried adding greater weight paint to the points but then I get almost no movement at all… Should I be painting the rope at a different weight to that of the sail?

Have you:

  • done the vertex parenting of each empty to the mesh it’s not hooking?
  • cleared your cloth/softbody caches after adding the empties?

Here’s my quick attempt:

To distinguish the two empties at each point I’ve made one display as a sphere and the other as an arrow.

You are right that if all the corner points have a pinning weight of 1.0, nothing happens. I gave the bottom corners of the sail a weight of 0.9, but left the ends of the rope at 1.0. As long as there is some ability for the attachment point to move, I doubt that it matters much whether it is in the sail or the rope or both.

Best wishes,

I think I have now worked it out. Apparently it is very important to do things in the right sequence.
Will try to post something useful when I finish.

You must have the hooks above the cloth/softbody in the modifier stack. That was my problem with my first attempt at a softbody rope: for some reason the hooks were added above the cloth for the sail, but below the softbody for the rope. When I moved the hooks up the stack things worked as expected.

Best wishes,

It looks like the ropes don’t actually exert a force on the sail, only the weight paint does. I need the ropes to pull the corners out and down at the same time. Any ideas?


The force exerted by the rope on the sail does depend mainly on the sail’s pinning group weight painting. My ropes are certainly pulling the sail corners in and down compared to where they would otherwise be - with appropriate changes in the geometry I’m sure they could pull out instead of in.

Here’s the .blend I’ve been using:


Best wishes,

Did you guys ever figure this out? I am trying to pull an anchor with a soft body rope. I could use some guidance.

Hi blane. Yes we worked it out (actually Matthew already knew), I now have cloth ropes pulling the corners of my sails down.
I’m not sure how a soft body would go, as above Matthew said that the ropes don’t track the corners properly and I have not experimented further as cloth works for me.
You could try the above steps with a soft body and it might work…
Good luck

[edit] whoops i think i submitted that twice, it told me there was an error the first time, sorry