softbody: sheet is way to stretchy

well i’ve been fooling with this softbody stuff for a bit.
i’ve got a sheet falling onto a cube (similar to how the video-tutorial is set up) and it doesn’t matter what i change, it’s way to freaking stretchy.
i’m trying to get something that moves like cotton fabric.

anyone know how to get this effect?

maybe too much gravity and/or mass?
have you got “use edges” turned off or turned too far down?


have you created a vertex group (select all vertex, new group, assign) and used that in the softbody settings?

Set the ESpring value to 0.9 or 0.95. Sometimes, depending on the mesh, 0.85 is also nice. Depends on your softbody and on the collision objects.

yup, done all that.
.99 on the edges still doesn’t tighten it up enough.

What you do is make a copy of your original “collision detection” meshes and the make them transparent. The object will hit them but it will look like it’s hitting the required object.

I think what you want is in the Particle interaction tab (in Object F7). In the tab there are a few options for interactions with softbodies. Play with the Inner, Outer, and damping values to get what you want. I’m not sure exactly what they do but it mainly alters the distance at which the softbodies are deflected. I’ll leave a more enlightened and detailed explanation to someone else.

The stretchiness comes from the mass. By default mass is 1.0. Tune it waay down (to 0.2 at most) and try again. You’ll get a much less rubbery object. Enjoy! :slight_smile:

i’ll give it a try.
thanks everyone for the ideas.

Gravity is way to high. I think 2 is nearer ‘true’ gravity. That with the mass would have been the problem.

There use to be a value on the tool tip - no longer there in 2.4a.

So i would seem like a problem with Mass/gravity? didn’t someone mention that :smiley: :wink:

That aside, are you using the latest CVS build, or an earlier one, I know I actually had some problems with saggy material in one but can’t remember which, things seem a lot better in the latest CVS.


changing mass or gravity makes no difference to the amount of stretch my plane is recieving. it only changes the rate at which it stretches.

enabling ‘stiff quads’ makes it deform much much less, but then i have springing faces instead of sagging ones… so you can tell it isn’t hanging right.

Actual gravity is 9.8 meters a second squared. So the gravity settings are about correct. = P

Actual gravity is 9.8 meters a second squared. So the gravity settings are about correct. = P[/quote]

Of course, what does Blender define as a meter? Also, how do you know that the gravity setting is in m/s^2 ? = P = P

Under “Jello” Soft Bodies

Increase “Grav” to about 9.8 (this simulates real-life gravity).


How about using the weight painting function to finetune the vertex weights for different parts of your cloth?

Apologies - my faux pas re: gravity.

(goes back to review how slow my cloth simulations are :wink: )

well you see any face with more than 3 edges can collapse (alter it’s) face area wihout violating edge lenght. so, for a cotton like materials you would need “stiff quads” on. In this case you can go down with edge stiffnes again to have less “ploppy” faces. For better simulation with stiff quads i’d subdivde the mesh once or twice.

I know things become real slow then. But at least for windows there’s a faster testing build.