Moho is designed in such a way that projects are split into "layers". You can have many, many layers in a Moho project, each representing a different element in a scene or animation, such as background scenery, a character, or a title. Some layers can even contain other layers, so a more complex object, such as a character, might contain separate layers for each arm and leg. Moho currently supports the following types of layers:
Vector Layers are used to hold vector-based artwork. These are the main type of layer you will use to create drawings.
Image Layers can be used to bring in images from other applications. Image files created in 3D programs or photo editing applications can be used in Moho with Image Layers.
Group Layers are used to group together multiple layers. If you created 20 layers with trees for example, you could put them all in a Group Layer and call it a forest. Group layers are a useful tool for organizing a complex project.
Bone Layers contain skeletons that are used to control the artwork in your vector and image layers. You manipulate skeletons as if they were "puppets" by bending arms and legs to make a character move.
Switch Layers are just like Bone layers, except they will only display one of their sub-layers at a time. Switch layers are an excellent way to perform lip-sync animation. Which sub-layer gets displayed is controlled by a switch data file. You can create this data file by hand, or better yet, use a lip-syncing program like Magpie or Pamela.
Particle Layers are used as a way to simulate water, sparks, smoke, crowds, or any number of effects that can be made up of many small objects. A Particle layer behaves somewhat like a Group layer, but instead of displaying each of its sub-layers, it can display many, many copies of each sub-layer arranged in sort of a "spray" formation. The sub-layers appear to be moving outward from the origin of the Particle layer.
3D Layers can be used to import 3D objects that were created in a 3D modeling program. 3D models can be a good source of background scenery. Or, use a 3D model for a character's head, and decorate it with eyes, mouth, etc. created with Moho's vector layers.
Note Layers are like sticky notes in Moho. You might use a note layer when you want to leave a note for yourself or another animator. For example, you might create a note layer at a particular frame that needs some work, or to describe why a character is set up in a particular way.
Drawings in Moho are vector-based. Vector drawings are different from pixel-based images (like a photograph) in that they use lines and curves to represent a picture, rather than a grid of colored pixels. This difference makes a lot of things easy in Moho that would be difficult or impossible to do with a pixel-based image.
First of all, since a Moho drawing is represented as a bunch of curves, you can reshape the curves at any time, without ever losing precision. Also, Moho projects are relatively small, even for complex animations - this means Moho doesn't require much memory even when working on a long movie. Vectors also have benefits when it comes to animation. By moving just a few points, you can totally change the shape of an object over time.
You're not restricted to vector artwork, though - Moho also has Image Layers. Using this type of layer, you can work with regular images within a Moho project. So, Moho is not strictly vector-based, but you will probably still use mostly vector layers, as image layers are not as flexible when it comes to animation.
Of course, most standard image and movie formats are not vector-based, so when you're done working on a Moho project, it must be "rendered" to create a traditional pixel-based image. During the rendering process, Moho can apply various effects to the objects, such as shading and blurring.