Rigging & animation · Intermediate

Blend shape

A saved, reshaped copy of a mesh you can fade in, like a smile

Also called Shape keys, Morph targets

What is a blend shape?

A blend shape is a saved, reshaped version of a mesh that you can fade in by any amount, from none to full. Animators use blend shapes for smiles, blinks and mouth shapes. Blender calls them shape keys, and many other tools call them morph targets.

Think of it like this

Like a dimmer switch for an expression: slide it up and the face eases from neutral into a full smile.

Where it fits in a 3D project

  1. Create
  2. Surface
  3. Rig
  4. Animate
  5. Render
  6. Export

Rig: Adding a skeleton and controls so the model can move.

How a blend shape works

  1. 01Start with the base mesh in its neutral shape.
  2. 02Make a copy and sculpt a new shape, such as a raised brow, keeping every vertex.
  3. 03Store that shape as a target linked to the base mesh.
  4. 04A slider blends between them, and you keyframe the slider over time.

Blend shape vs bones

PropertyBlend shapeBones
Moves vertices byA stored position for each vertexRotating rigid segments
Best forFaces, muscle bulges, small fixesLimbs, spines and big motion
SetupSculpt each shapePlace bones and paint weights
File sizeGrows with every shapeSmall

Use bones for big moving parts and blend shapes for subtle surface changes; most character faces combine the two.

Where a blend shape is used

  • Facial expressions and lip sync
  • Correcting a bad bend at an elbow or shoulder
  • Morphing one shape smoothly into another

Beginner tip

Never add or delete vertices on the base mesh after making blend shapes. Each shape stores a position for every vertex, so changing the count breaks them.

Terms related to a blend shape

Blend shape FAQ

What are shape keys in Blender?
Shape keys are Blender’s blend shapes. Each key stores a version of the mesh, and its value slider mixes that version in on top of the base shape.
What are morph targets?
Another name for blend shapes, common in game engines and web 3D formats. A morph target is a stored set of vertex positions that the base mesh can blend toward.
Why use blend shapes for facial animation?
Faces fold and bulge in soft ways that bones struggle to match. Blend shapes let an artist sculpt each expression exactly, then mix them. Face capture apps often drive a standard set of them from a phone camera.

Updated October 29, 2026 · Browse all 3D terms