App now supports 3 types of animations

Initially skeletal animations were the only type supported, but recently both blend shape and node-only animation support was added. There’s a video and more details about each animation category are provided below for your perusal…

Skeletal animations

This is what usually comes to mind when discussing animation: models with a “skeleton” made up of CG “bones.” Each “bone” affects a set of vertices via a set of weights; when the bone moves, its affected vertices move in proportion to the weight. So usually a humanoid or animal character will consist of as few as a single mesh, and the bones control the deformation. Once the animation has been keyframed, the character can come to life in a very realistic manner!

Morph targets/blend shapes

Known by various names including “morph targets” and “blend shapes,” this type of animation involves taking a mesh of an object, making a copy, and deforming it. Then repeating for another “pose.” A good example is for facial animation; there will usually be a neutral facial expression on the base mesh, then a copy is made and deformed into a smile, another into a frown, etc. Afterwards the meshes can be used to generate a dynamic “in-between” mesh, which uses say 30% of the neutral mesh, 50% of the smile mesh and 20% of the frown mesh to create a new face. Usually these blend shapes are used by animators to achieve effects which would be difficult using bones, but in rare cases 3D models are available with keyframed animations using the blend shapes.

Node only “bulk” mesh animations

For this type of animation there are no bones and there are no morph targets. In fact, the only thing that can be done with a single mesh is to spin it, move it around or scale it up and down; since there’s no bones are alternate shapes, no deformation is possible within a mesh! But, if each bone in a 3D model of a human skeleton, or each section of a 3D model of a robot arm, were a separate mesh, then a very convincing IK (Inverse Kinematics) animation could be represented with no bones or blend shapes required!