Simplify your blend shape creation

Discover how to create blend shapes with greater speed and efficiency with this quick step-by-step guide

Antony Ward delivers a guide to efficient blend shape creation

Blend shapes, or morph targets as they are also known, are a powerful way to bring life to a static model. You create a target shape and then your model can blend into and out of this using a slider, so it’s a nice organic motion, even if it is a linear movement.

Traditionally, creating blend shapes could be a long and tedious job. You first duplicate the main model, let’s say it’s a head, edit each vertex to create your expression and then repeat the process for all the other face shapes you need. As you can imagine, on those more complicated projects this could involve generating 50 or more shapes so the character or creature you’re working on can express emotions.

The biggest issue with this approach is if the main head model’s topology changes. What this used to mean was all the target shapes had to be updated too, or in the worst case, redone.

There have been lots of improvements in blend shape creation over the years and some shortcuts have been developed to help speed up generation and prevent the need for any work to be repeated.

I use a mixture of methods which involve utilising the component editor, painting blend shape weight values, and I like to create a blend shape generator of sorts to automate shape creation while also making potential changes future proof. However, the biggest improvement was the introduction of the sculpting tools, and also the Shape Editor.

01 YOUR FIRST TARGET SHAPE

The Shape Editor can be found on the sculpting shelf. When you first open it, Maya will automatically scan the scene for any existing blend shape nodes and fill the window for you. If none exist all you need to do is select the head model and then click Create Blend Shape.

This creates the main container node called blendshape1, but you then need to define your first target shape which the head will blend into. To do this, just select the blend shape node and then click Add Target.

02 THE EDIT BUTTON

What I like about the Shape Editor is there are no separate models to play with, everything is held within the blend shape node. This not only makes for a cleaner scene, but also a smaller file.

What you must remember is to hit the edit button next to the target you’re working on, so Maya knows which shape to manipulate. Maya will helpfully give you a warning if you try to work on a target that isn’t editable, but if you aren’t careful you will end up changing a shape you’re not working on, and if it’s not currently visible you may not see the edits until it’s too late.

03 SCULPTING TOOLS

Defining your target shape is made even easier with the help of the sculpting tools. The Grab tool is essential for pulling the face around, meaning you can quickly achieve organic-looking expressions with just a few strokes.

Other key tools are the Smooth tool, which you can also access by holding Shift, and the Relax tool. What this will do is spread the distribution of the vertices across the model’s surface, while retaining its shape. This is good for fixing areas where there is texture stretching, and is also handy for fixing the topology.

04 SHAPE EDITING

In addition to the main sculpting options there are also a series of tools geared more towards blend shape creation, and these are found at the end of the sculpting shelf.

These are the Smooth Target tool, Clone Target tool, Mask Target tool and the Erase Target tool. What’s useful about these is they focus more on the targets you’re working on, so it reduces the risk of inadvertently editing the other shapes.

05 TRADITIONAL TOOLS ARE STILL ESSENTIAL

As good and as intuitive as the sculpting tools are, there are times when you need more precision, but luckily, targets don’t just have to be edited by sculpting them.

You can still work on them at a component level, meaning you can fine-tune the shape vertex by vertex should you need to. What also helps is the Soft Selection tool, which gives a gradual falloff from your selection, meaning the surrounding geometry is

Go deeper As well as having the ability to create and manage all your blend shape targets in one place, the Shape Editor has a whole host of other useful features. You can create inbetween targets and combination shapes too which can help to make your character’s movements even more fluid and organic. If you decide later you prefer to work on separate models, you can also use the Rebuild Mesh tool which will output a mode for you to edit directly without worrying about changing other shapes.