Creating a chain with links using Blender

Overview

This tutorial will explain how to create a chain with links in Blender using arrays and curves. The idea behind this is that we will create a link, clone it several times, draw a curve and the line of links will follow the curve automatically, using the Array and Curve modifiers. This technique can also be used to create any other mesh whose shape follows a curve, either open or closed, like necklaces, bracelets, straps, etc.

This tutorial assumes that you have a basic knowledge of Blender. If that is not the case I recommend you to read and practice with these tutorials Blender 3D: Noob to Pro

Required tools

• Blender

Creating a chain with links

The main steps for creating a chain with links in Blender are:

1. Create one link
2. Duplicate the link and rotate the second link
3. Add a curve and work with it
4. Finishing touches

Create one link

In this tutorial we will create a necklace, then the first step wil be to import into Blender the body (head and torso) we are going to create the necklace for. Once this is done, in a new Blenedr layer add a Torus (a doghnut):

1. In Object mode select the menu option Add -> Mesh -> Torus.
2. In Edit mode select all the vertices that are in one half of the torus and move downwards as shown in picture Creating one link.
3. Compare the link's size to your character's size and scale down the link as required.

Duplicate the link and rotate the second link

To duplicate the link you've created add the Array Modifier:

• In Object mode select the link
• Press the Add modifier button and select Array from the drop down list. You'll see that there are now 2 links in a row.

A link in a chain is rotated and partially inside the previous one. To make the row of links follow that behaviour we are going to use an empty mesh:

• In Object mode select the menu option Add -> Mesh -> Empty mesh
• Select your link and in the Array modifier section (see picture Rotating and moving links):
  • Deselect the Relative Offset button
  • Enter the name of the Empty mesh you've just added in the Ob: box under Object Offset
  • Select the Object Offset button
• Select again the Empty mesh and:
  • Move it downwards (along the X axis, the red arrow, in the example) until the second link is in the right place. You'll see that, by moving the empty mesh you are moving the second link while the first one stays in place.
  • Rotate it perpendicularly to the direction you've move it before (rotate it perpendicularly to the X asis in the example). To rotate it exactly 90 degrees, type 90 in the keyboard. You'll see that rotating the empty mesh will rotate the second link while keeping unchanged the first one.

Increase the number in the box Count of the Array modifier from 2 to another number and you'll see that more links appear in the row, each one rotated and with a relative position with respect to the previous one following the position and rotation rules you've set with the Empty mesh.

Add a curve and work with it

We are adding a circle because we are going to create a necklace. In Object mode add a circle using the menu option Add -> Curve -> Bezier Circle.

Note: If you are making a chain that doesn't have a closed shape, you can add a curve instead of a curve (Add -> Curve -> Bezier Curve). The process for working with curves is the same than the one described here for working with circles.

Now we are going to give the circle the shape we want for the necklace. Use the body or the clothes you imported previously as a guide. In this example we are going to create a necklace that will conceal the neck seam, and then we are going to give the circle the right shape to do this:

1. In Object mode select the circle
2. Go to Edit mode, select all control points (press A once or twice) and move the circle so it is around the neck as shown in picture Adding a circle. You can also scale down the circle diameter by selecting all control points and selecting the menu option Curve -> Transform -> Scale.
3. If you have to move the circle up or down, you can make it a 3D object by selecting the 3D button of the Curve and Surface area shown in picture Adding a circle.

Once you've positioned the circle at its place, move or rotate each of the control points to give the circle the required shape:

• If you need to add more control points to get the desired shape, select two consecutive control points and and select the menu option Curve -> Segments -> Subdivide. This creates a new control point between the two we had selected.
• You'll see that each control point is a line that has 3 vertices:
  • If you select the central vertex, you will move the 3 vertices of control point at the same time.
  • If you select one of the vertices at the sides, you'll rotate the control point around the central vertex. If you want a smooth curve, the lenght of all control point branches should be the same.

After working with the control points of the circle you will get a shape similar to the one shown in picture Circle that covers the neck seam.

Now we are going to make the chain to follow the circle:

1. In Object mode select the link you created at the beginning of the tutorial and press the Add modifier button. Select Curve from the drop down list.
2. In the Ob: box enter the name of the circle as shown in picture Adding the Curve modifier. You'll see that the links position themselves on the circle, like in the picture.
3. Increase the number in the box Count of the Array modifier until the chain of links covers the whole circle.

   Notes:

   * Clicking on the X, Y, Z, -X, -Y and -Z buttons of the Curve modifier, you are changing the orientation of the link when following the circle. You can try these options and choose the one that works best for the chain.

   * If now that you are comparing the link size with the body or clothes, you see that have to change it (making it smaller, thinner, ...) select the link in Object mode and change its shape in Edit mode. Then go back to Object mode, select the curve and edit it in Edit mode

   * It can happen that where the first and the last link join look wrong as shown in the example in picture Last and first link. To fix this, edit the circle shape until the links join right (for example making the circle a little bigger).

Finishing touches

Once your necklace has the right shape it is time to freeze its shape.

Note: If you are going to create a UV map, it is a good idea to create for the link before applying the Array modifier: this way you'll have to create only the UV map for one link and all other links will share the same UV map automatically when made real.

Until now you could repeat the process almost from the beginning and see how each change in the circle or in the position and rotation of the Empty mesh affects the chain of links but once you freeze the shape you won't be able to modify it again so easily, that is why it is advisable that you save what you've done in a Blender file as a backup and work on a new copy.

To freeze the shape of the necklace:

1. Select the link in Object mode
2. Go to the modifiers area and click on the Apply button that is at the right side of the Array modifier.
3. Then click on the Apply button that is at the right side of the Curve modifier.
4. Now you can delete the circle and the Empty mesh objects by selecting them in Object mode and pressing the Delete key.

From here you can work with the necklace as you would do with any other object in Blender (reduce polygons, assign weights, add materials, etc) and then export it as a nif file to use it in your game.

Related pages

• Creating a belt using Blender