Blender Shape Keys guide: Set up model deformations step by step

What will you learn in this guide?

Blender Shape Keys let you manage shape changes by storing different vertex positions for the same object. This method isn't limited to character facial expressions: it can also be used to change specific parts of a model in a controlled way or prepare a transition from one shape to another. Shape Keys are also known as “morph targets” or “blend shapes” in other applications.

In this guide, you'll learn how to create a base shape for an object, add and edit new keys, blend deformations using values, and decide when to use Relative or Absolute keys. Examples in the Blender documentation include facial animation, muscles and correcting a skeletal rig. The steps here focus on understanding how Shape Keys work and don't require a specific character or scene file.

Requirements

• You need an installation of Blender with access to the Shape Keys panel and an object containing vertex data. The examples use a mesh; curves, surfaces and lattice objects are also listed among the supported types in the documentation.

• Blender's 5.2 LTS User Manual describes the panel and its features. The 3.6 manual also explains the basic workflow. Keep in mind that interface labels may vary depending on your version.

• The source manuals don't specify a user account requirement; there is no information indicating that an additional online account is needed for this workflow.

• Since new keys store vertex positions, stabilize the model's vertex count and connectivity before setting up Shape Keys, if possible.

Create Shape Keys step by step

1. Prepare the base model

Select the object you want to deform and make sure its base shape is complete. Shape Keys store the object's vertex positions; the model's topology determines the number of vertices and how they connect. Although the Blender documentation explains that vertices can be added or deleted after keys have been created, it recommends stabilizing the topology beforehand for a smoother workflow.

For this reason, it's useful to review the model's base mesh before starting work on a facial expression, joint correction or other shape change. If you need to edit the topology later, check the keys' effects as well; a Shape Key doesn't create new vertices or connectivity on its own.

2. Find the Shape Keys panel

With the object selected, open Object Data properties in the Properties editor and find the Shape Keys panel. The panel brings together the tools for creating, ordering and managing keys. Keys appear in a tree view in the list and can be reordered by dragging.

Start with the Basis key, which represents the base shape. Basis is the first key in the list and represents the object's starting positions. It serves as the default reference for comparing other shapes and has no weight value of its own.

3. Add a new key

Create a new Shape Key using the add button in the Shape Keys list. The documentation notes that a key added this way starts as a copy of the Basis shape. You can then select the new key and move the object's vertices to create a different shape.

Make sure the correct key is active while editing. If the effect isn't clearly visible, increase that key's Value in the panel or check the values of the other keys to review the result. You can use the mute option in the panel to temporarily remove a key from the blend.

4. Edit and check the deformation

After selecting the key you created, move the object's vertices to their new positions in the 3D Viewport. According to the Blender manual, a Shape Key stores a position for each vertex; the key itself doesn't change the topology. For example, when creating a facial expression, edit only the intended shape change and adjust the key value to check its effect.

To reduce the risk of accidentally editing the wrong key, consider using the locking option in the Shape Keys panel. A locked key helps prevent accidental changes with many sculpt and edit tools. However, the documentation notes that most operations that change topology don't check this lock, so don't treat it as general protection against topology changes.

5. Blend shapes with Relative keys

Use Relative Shape Keys if you want multiple shapes to have an effect at the same time. With this type, each shape is defined relative to Basis or another selected key. The Value determines how much that shape contributes to the blend relative to its reference: 0.0 corresponds to the reference shape, while 1.0 corresponds to the full effect of that key.

The result is the combined blend produced by the keys' current values in the viewport. When a value is outside the 0.0–1.0 range, Blender can extrapolate the deformation or apply it in the opposite direction. Check the model at different values when using this behavior; if the result is unexpected, inspect the reference key and other values too, rather than assuming the key's shape is the only cause.

6. Create sequential transitions with Absolute keys

Use the Absolute Shape Keys option when the goal is to change shapes in a specific sequence over time rather than blend them together. In this setup, each key corresponds to an Evaluation Time value. The current time determines the interpolation between the preceding and following keys.

Change the Evaluation Time value in the panel to review the transition. The Blender documentation explains that this value can be keyed for animation or controlled with a driver. Absolute keys also support retiming and different interpolation types, including Linear, Cardinal, Catmull-Rom and B-Spline.

7. Use combined shapes and additional editing tools

If you want to save the visible result of the current blend as a new key, consider the New Combined option in the panel. Rather than copying only the Basis shape, this creates a key based on the currently deformed shape. The panel also includes options to copy keys, import shapes from other objects or update keys with matching names, if needed.

When transferring data from other objects, the meshes may need to have matching topology. For mirrored key operations, also check the symmetry or topology requirements of the operation. For example, Flip expects the mesh vertices to be exactly symmetrical along the X axis, while Flip (Topology) can detect matches based on topology.

Common mistakes

• Changing topology too early: Shape Keys store vertex positions; they don't set up vertex and connectivity layouts. Complete as much of the model's topology as possible before creating keys.

• Editing the wrong key: Before making changes, check the name and selection state of the active Shape Key. Use the locking option if needed.

• Evaluating values individually instead of together: The effects of Relative keys accumulate in the blend. If the result differs from what you expected, review the Value settings and references of the relevant keys together.

• Using Relative and Absolute for the same purpose: Choose Relative for a weighted blend of multiple shapes; use Absolute for a sequential transition over time with interpolation.

• Ignoring topology requirements when transferring: When importing keys from other objects or mirroring them, check the topology and symmetry requirements specified in the documentation.

Next steps

For your first test, create a small, easy-to-observe deformation and change the Value to check the result. Then try blending several shapes with Relative keys, and in a separate test, explore a sequential transition with Absolute keys. If you're working on a character or organic model, review the deformations individually and together to check whether they conflict.

At a more advanced stage, you can explore operations such as changing the reference key, applying a key to Basis or applying all existing Shape Keys. These operations can affect the model's base shape and key list, so it's important to decide which shape to preserve before applying them.

In architecture and interior visualization, Shape Keys may be useful to teams that want to review different shape states of an object on a single model. However, the sources don't limit this feature to a specific architectural workflow; its suitability depends on the model and the intended animation. Before handing over a project file, check the key blend, the object's topology and whether the available panel options are compatible with the software version in use.

Sources and license

This guide is adapted into Turkish from the Shape Keys introduction, panel and basic usage sections of the official Blender User Manual. The sources used are licensed under Creative Commons Attribution-ShareAlike 4.0 (CC BY-SA 4.0).