How to Rig a 2D Character in Blender for Cut-Out Animation or Explainer Videos: Part 1

Building the Character

Step 1

In the paint program, construct the character such that all the movable items, such as limbs and head, are in separate layers. 

Move them apart so that there is ample space between them. Turn off the background layer and export it as transparent .png file.

Step 2

Open Blender and in a new file, press A to select all default objects and press Del to delete them.

Step 3

With the mouse in 3D viewport, press 1 in the number pad to get into front view. 

Press 5 in the number pad to toggle off perspective view. 

Press N to bring out the properties panel and tick the Background Image check box.

Click on the Add Image button. 

Press the Open button and browse for the image.

Increase the Opacity to 1.

Step 4

Press Shift-A and add a Plane.

In the Tool Options panel, which is located at the bottom of the tool shelf, tick the Align to View checkbox so that the circle is not facing upwards.

Press T to toggle on the Tools Options panel if it is not there.

Step 5

Secondary-click the mouse on the plane to select it. 

Press Tab on the keyboard to enter edit mode. 

Press Z for wire-frame mode so that you can see through the mesh.

Step 6

Press A to select all vertices of the mesh. 

Press G to move the mesh and place it such that it covers the arm. 

Select the top two vertices and move them just a little above the shoulder. 

Secondary-click on the vertex to select it and hold Shift and then right click again on to select more than one. 

Press G key to move.

Step 7

Use the B key and drag select vertices. Select the vertices on the side. Move them closer to the arm.

Similarly, move the other two vertices closer to the arm.

Step 8

Move the mouse over the mesh. 

Press Ctrl-R to insert an edge loop. 

Primary-click to confirm. 

Move the mouse up or down to place the loop cut at the elbow. 

Primary-click again to confirm the position.

Step 9

Similarly add few more edge loops, total three for elbow and two for wrist. This will help deform the mesh according to the bone movement.

Step 10

In the properties window, click the modifiers button. 

Press the Add Modifier button and select Subdivision surface. This will smooth out the mesh.

Click on the cage button to preview the effect of the modifier while editing.

Step 11

Tweak the vertices around so that it covers the arm. Remember, secondary-click on any point to select it, then press G key on the keyboard to move.

Step 12

Press the B key and drag select all vertices. Press Shift-D to duplicate the mesh. Move the mouse towards the second arm and primary-click to confirm the position.

Tweak the new mesh so that it covers the second arm perfectly.

Step 13

For the legs, add another plane. Make sure you are still in the edit mode. Press Shift-A and click on Plane.

In the toolshelf, check Align to View so that the plane is facing correctly towards the viewer.

You'll see that the plane is not a perfect square. This is because of the subsurface modifier which was already applied to the object in step 10.

Step 14

With the new plane select,

• press G key and move the new plane on top of the leg.
• Press A to deselect all vertices. Hold Shift and then secondary-click on the bottom two vertices to select them.
• Press G and move them down, just above the knee. Primary-click to confirm the position.
• Press E to extrude them. Move the mouse to move the new set of points downwards. Primary-click to confirm.
• Similarly extrude again few times to make the whole leg till tow.
• Press S to scale down the last two vertices.

Step 15

Press B and drag select all vertices of the leg. 

Press Shift-D to make a copy, move the mouse and place the duplicate over the second leg. 

click to confirm the position.

Step 16

Press Shift-A and add a new plane. Tick the Align to View checkbox so that it faces the viewer.

Step 17

Similarly, with the same method, extrude along and build the torso. Press S key to scale down the vertices for neck.

Step 18

Press Shift-A to add another plane for head. Scale it to match the reference. 

Press Ctrl-T to add edge loops. 

Tweak the vertices.

Step 19

Remove the background image. 

Click on the cross button in the Background Images panel. 

Press N to see or hide the properties panel.

Step 20

Click on the object button in the properties window. Rename the model to Character or another name of your choice.

Texturing the Character Object

Step 1

Split the 3D view by dragging the top corner with primary-mouse button.

Click on the window type button and select UV/Image Editor.

Step 2

In the 3D view, press A on the keyboard to select all vertices.

Press U to bring out the UV Mapping menu and select Project From View. This will unwrap the vertices onto the UV editor.

Step 3

In the UV Editor, click on the Open button and browse for the character image.

Step 4

In the UV editor, press A to select all vertices. Press S to scale them to match the image.

Step 5

In the 3D viewport, press Alt-Z to set the Viewport Shading to Texture. You can also select this by clicking on the Shading button in the 3D viewport's header, and selecting Texture.

Re-arranging The Character Mesh

Step 1

In the 3D viewport, press C and brush select all vertices of any leg.

Step 2

Press G and place it below the torso. Similarly place all parts where they belong.

After placing all parts, press A to select the whole mesh. Press G and move it on top of the origin point of the object, which is the orange dot.

Step 3

Select the parts which you want them to be in front. Rotate the 3d view by dragging the middle mouse button. 

Select the mesh and move them forward with the help of the arrow manipulator. Similarly push back the mesh which are suppose to be behind.

Press Tab to exit the edit mode. The character is now ready to be rigged. Press Ctrl-S to save the file.

Armature Setup and Rigging

Step 1

Secondary-click on the Character object and press Tab to go back into edit mode. 

Move the mouse over the arm and press L to select the connected vertices, i.e. the arm. 

Press R key on the keyboard to rotate the arm so that they are spread out and little bit away from the body. 

Do the same for the other arm. It will be easy to rig the object in this pose.

Step 2

Press Tab to exit edit mode. Press Shift-A and add an Armature.

Click on the Armature button in the properties window. In the Display panel, tick the X-Ray checkbox. 

This will help see the bone through the object.

Step 3

With the Armature object selected, press Tab to enter edit mode. Select the bone with right click and press G to move behind the back. Press R to rotate it, as shown in the image.

Step 4

Secondary-click the the tip of the bone to select it. 

Press E to extrude out a bone for stomach. 

Move the mouse upward and primary-click to confirm. 

Similarly extrude out bones for chest and head.

Step 5

Secondary-click on the tip of the first bone again to select it. 

Press E to extrude out another bone downwards for pelvic. Primary-click to confirm.

Step 6

Primary-click above the leg to place the 3D cursor there.

Press Shift-A to add a new bone. 

Secondary-click on the tip and press G to move it down. Primary-click to release. 

Press E to extrude a bone for shin and another for foot.

Step 7

Hold Shift and then secondary-click on all three bones of leg to select them. 

Press Shift-D to duplicate them. 

Move the new copy over the second leg and primary-click to confirm.

Step 8

Similarly create bone set for the arm. Primary-click on the shoulder to place the 3D cursor. Press Shift-A to add new bone and then rotate it. Extrude out the new bones for arm and palm.

Step 9

Duplicate the arm set for the other arm, or create a new set.

Step 10

Secondary-click on the head bone to select it. 

Click on bone button on the properties panel. Rename the bone Head. 

Similarly rename all bones. Use extension .l and .r to distinguish between left and right bones. For example arm.l and arm.r.

Step 11

Secondary-click on the arm.l bone. 

In the bone properties, under the Relation panel, set the Parent bone to Chest. 

Do the same for the other arm. This will set the chest bone as parent bone, and the arm bones will follow its movement.

Similarly set the pelvic bone as parent for the thigh bones. Secondary-click to select the thigh bone, and in the Relations panel set Parent to pelvic.

Step 12

Press Tab to exit the edit mode. 

Hold shift and sceondary-click on the character object first and then on the Armature. 

Press Ctrl-P to make the armature parent. 

In the menu select With Empty Groups. This will create vertex groups with bone names but will not assign any vertex to any bone. You'll do that manually.

Step 13

Press A to deselect all objects. Secondary-click on the character to select it. Press Tab to enter edit mode. 

• Click the Object Data button in the properties window.
• In the 3D view, select all the vertices of the head. Either hold Shift and then secondary-click  each vertices or move the mouse over the head and press L to select connected vertices.
• Click head in the Vertex Groups panel.
• Click the Assign button.

This will assign the selected vertices to the vertex group named Head, which is already assigned to the bone name Head.

You can test by moving the bone in the pose mode. Press Tab to exit edit mode. Secondary-click on the armature. 

Press Ctrl-Tab to enter pose mode. In pose mode, the bones will turn blue when selected. Secondary-click on the head bone and press R to rotate it. Press A to select all bone and press Alt-R to reset the rotation. 

Step 14

Secondary-click on the character object, and press Tab to enter edit mode. Select only the vertices which you want to assign to chest. 

Ensure you deselect any previously selected points. Click on the Chest in the Vertex Groups and click on Assign button.

Step 15

Similarly assign vertices for stomach and pelvic.

Step 16

Move ahead to the arms. Select the upper part of the arm and assign it to arm.l vertex group. 

Select the lower part and assign it to hand.l. There will be common vertices of the joint (elbow) on each group.

Similarly, the palm vertices to palm.l. Again the wrist vertices will be common in hand.l and palm.l vertex groups.

Step 17

Similarly do the same for both legs one at a time.

Step 18

Press Tab to exit edit mode. Secondary-click on the armature object. If it is not in pose mode, press Ctrl-Tab to enter pose mode. Select any of the bone and press R to rotate and see the effect. Press A to select all bones and press Alt-R to reset the rotation.

Step 19

Next I will add the IK, or Inverse Kinematics, setup. This helps in posing and animation. Secondary-click on the tip of shin bone to select it. Press Shift-S and click on Cursor to Selected. This will bring the 3D cursor to the selected bone tip.

Step 20

Press Shift-A to add a bone. Secondary-click on the tip of the new bone and press G to pull it down. Primary-click to confirm.

Step 21

Secondary-click on the new bone to select it. Click on the bone button in the Properties window and rename the new bone ik.l.

Step 22

Press Ctrl-tab and switch to pose mode. You can also select Pose Mode from the header. Secondary-click on the shin bone to select it.

Step 23

With the shin bone selected, click on the bone constraint button in the properties window. Press the Add Bone Constraint and select Inverse Kinematics.

Step 24

In the IK panel, set Target object to Armature. Bone to ik.l. Increase the Chain Length to 2.

Select the IK controller bone (ik.l) and press G and move it around to test it. To reset the position and rotation, select all bones with A key and press Alt+G, to reset location, and Alt+R, to reset rotation.

Step 25

Select the other lower leg bone (shin.r) and add the Inverse Kinematics Constraint to it.

Use Armature as target and ik.r as target bone. Set chain length to 2. Basic armature setup is now ready. 

Play with some poses in the pose mode. To move the legs use the IK controllers.

Material Setup

Step 1

Secondary-click on the character object to select it. 

Click on the Materials button in the properties window and press the New button to add new material.

Step 2

Rename the material to character or anything you want. In the Shading panel, tick the Shadeless checkbox. 

Tick the Transparency checkbox in reduce the Alpha to 0.00.

Step 3

With the object selected, click on the texture button in the properties window. Click the New button.

Step 4

In the Image panel, click on open button and browse for the character texture image. Tick Show Alpha checkbox to preview the transparency. 

In the Image panel, tick the Use Alpha checkbox. In the Influence panel, tick Alpha. The material and texture setup is now done.

In the next part I'll show you how to animate mouth and other expression using UV Warp modifier.