# Pulling a net tight

I am trying to drape a net using the cloth physics, but then is there a good way to make it look like the four corners are pulled and "staked" in a certain place? My first thought was some kind of force field, but then I was curious if I could somehow pin the corners of my net to the plane. Maybe the best way is to just do it manually. I'm very new to Blender so just looking for some direction. Here is an example of the net without the corners being pulled tight to the plane.

• There are pins and also seams strings that can help in this. Coudl you better describe the behaviour of the four corners? Should they be pinned far from the poles? And is this for animation or just modeling? Commented Jul 17, 2018 at 19:42
• I would want the four corners to be as far from the poles to where it looks tightened around the objects, and pinned to the ground. This is just for modeling. It would eventually be exported as an obj for a computational test bed. Commented Jul 17, 2018 at 20:01

## Cloth Sewings springs

I would add a sewing edge to each corner of the surface and set its ending point to a pinning group.

From the linked page of the manual:

...Sewing springs are virtual springs that pull vertices in one part of a cloth mesh toward vertices in another part of the cloth mesh.

Extrude the corner vertices and assign the edge and the new vertices to a different vertex group:

Starting from a similar scene where there is a single mesh acting as an obstacle and a grid surface falling from the top by the scene gravity and with cloth physic enabled, you should first of all enable the collision for the cloth:

Notice how the pinned vertex stay still on the ground because Pinning checkbox is was enable. The sewing edes are now simply connecting the vertices the belongs to by freely altering their lenght

Then introduce the sewing force and start tweaking the parameters (in the following image sequence are greyed out because I baked the simulation):

You'll probably have to lower the friction parameter too, gradually increase the resolution and quality of the simulation to achieve best results. For example I had to smooth out the top faces of the obstacle in order to lower the friction and transmit tension across the whole surface.

Finish by introducing the Sewing Spring vertex group in the Shrinking to restrict the tension only on the edges if that is the kind of simulation you are aiming to.

Here's what a possible result could look like by using the Shrinking group.

Notice how next to the 3D cursor the cloth is clearly not pulled, while in the previus example there were a bit of tension in that place also.

• That is very cool. Commented Jul 17, 2018 at 20:32
• This is great, thank you. Just to clarify it is a combination of using the sewing springs and reducing the friction on the obstacles that gets you from your first messy drop to the tight drop at the end? Commented Jul 17, 2018 at 20:44
• @fatalaccidents yes, in conjunction with the increased quality of the cloth and cloth collision simulation. As every simulation, start low and then gradually tweak things. Just adding the sewing springs should put you in the right direction, but then is a work of fixing things. In my example I also had to increase the pole end size, because the net was trepassing the tip... Commented Jul 17, 2018 at 20:50
• @Carlo I seem to be having an issue. I know how to apply pinning, but where do you apply the seams springs. It would seem like it would be in the shrinking, but yours is not that way. Lastly, I can only see the extruded vertices in edit mode, and they were ignored in the pin. I'm a bit new, so it might be something very simple. Edit: I had not applied the wireframe modifier, that fixed seeing it. Still don't know where to apply seams strings Commented Jul 17, 2018 at 21:11
• @fatalaccidents My mistake...:) Yep, I forgot to target the vertex group I prepared! So in the simulation shown, it's actually using all the edges as seaming springs. Well, it's not working badly: probably with the group the pull towards the edges will be more prominent, but the ending result should be similar. I suggest anyway to start with little examples to take confindence with the workflow and then grow in complexity from there. i.sstatic.net/kgxz9.gif Commented Jul 17, 2018 at 21:34

## Pinning with Hooks

Animated example:

"Interactive" example:

## Overview:

1. Select your corner vertices and put them to the Vertex Group, that you will use as a Pinning.

2. Create as many Empties as pinned vertices. They should be in the same place. Create Hooks for those vertices with each Empty. I have done it by selecting Empty in Object Mode than with SHIFT selecting Plane, go to Edit Mode, select vertex and CTRL+V > Hooks > Hook to Selected Object.

3. Animate Empties.

Note: For creating net you can utilize this method: How to create and design hoops net and attach ot to a hoop?

• Thanks ! How do you clear the cloth cache ? Actually I have to remove the cloth and set it again for my animation being correctly updated. Commented May 3, 2022 at 11:52
• @gordie it should update after any change automatically... Try changing any settings in cloth panel and see if it works. Commented May 6, 2022 at 23:21
• ok, thanks. + how do you achieve this "interactive" example ? You've got realtime in the viewport ? Commented May 13, 2022 at 12:08
• It's not real time. Just set very long animation and hit play ;) Commented May 15, 2022 at 15:30