Introduction

In this lesson, I was introduced to blend shapes in Maya, and was able to use them to practise 3D animation. To recap previous sessions, the class has looked at animating along a path, using a rig to animate in 3D and applying it along a path, as well as animating using set driven keys. This lesson is building upon the 3D animation skills we have learned so far, by teaching the use of Blend Shapes in Maya.

Research Task

The first task was to research Blend Shapes. Blend Shapes are classed as Deformers in Maya, which are tools that allow the user to transform or deform 3D shapes, in a way that using keyframes and the move, scale, rotation tools cannot. Blend Shapes are used heavily in animating facial expressions, as they allow for seamless transitions between different shapes. They are also used to improve the topology of an animated asset. It also speeds up the process of animating faces, as keyframing every muscle on the face rig would be a long task for a 3D animator.

Using Blend Shapes Task

The next task was to follow along with a demonstration to introduce the class to Blend Shapes. To test out the blend shapes tool, I first created four spheres in the Maya scene and, in vertex mode, scaled their vertices to deform them.

You can see how I changed the spheres below.

Next, I selected all of the duplicate shapes and shift selected the sphere and clicked on the ‘Blend Shape’ option under the ‘Deform’ menu.

What this did was allow me to deform the sphere on the left to each one of the other shapes by using a slider in the attribute editor.

But in a real animation, you would only want to see the shape that is being deformed, and not every shape at once side by side. To get rid of the other shapes while still being able to change the form of the sphere using their attributes, I opened the channel editor and selected the first shape I wanted to disappear. In the channel editor, I selected the ‘create new layer and assign selected objects’ option and this created a new layer that was just for the selected shape, which I could then turn invisible by unticking the V box.

I repeated this for all the other shapes and as you can see, the sphere is only seen in the scene, but it can still be controlled using the sliders for the other shapes.

To keyframe this movement, I was able to right click and select the set key option as I changed frames in the timeline.

Animating a face with Blend Shapes

Next, I did a similar thing to animate some facial expressions. I duplicated this head asset 3 times:

Next, I entered vertex mode and hit the B key to use soft select mode. To change the size of the soft select, I held the left mouse button and the B key and moved the mouse left and right.

I could select a vertex and move it to morph the mesh of the face, and warp it into different facial expressions.

I created a set of three facial expressions, like the three difrerent shapes I created in the previous task. I followed the same steps to make the three extra expressions disappear, and keyframed the face to change through the different expressions.

This is the animation I created:

Conclusion

Over all, this is a very useful tool for animating faces for 3D animation. I’ve seen this technique being used extensively in videogames and movies like The Elder Scrolls IV: Oblivion and the magic mirror from Shrek.