What are art layers?

Art layers are available on each drawing frame in Harmony and are used to strategically separate artwork. They can be used for many tasks, but are most commonly used for paperless animation, rigging, and compositing.

What is an art layer?

Art layers are separate layers within layers and can be used to divide artwork for specific tasks. An art layer acts similarly to a regular layer, but with the following differences:

• You cannot control the order or naming of art layers in the Art Layer toolbar, but you can change their visual order in the Camera view by using node systems.
• You cannot control the number of art layers, but you can deactivate half of them if not needed.
• Art layers cannot be hidden individually like timeline layers, but there are other ways to hide them by using Node systems.
• Art layers exist within each drawing frame of each timeline layer. If you select another frame, the art layers will change or be blank depending on what you’ve drawn on the layer.
• You cannot animate art layers separately. They will follow whatever keyframe animation is applied on the timeline layer.

Where can I find the art layers?

The art layers can be found on the Art Layer toolbar, located down the right-hand side of the Camera and Drawing views.

What types of art layers are there?

The following art layers exist in Harmony:

	Overlay Art layer: Must be activated in the Preferences to be seen. The topmost art layer.
	Line Art layer: The default art layer. All artwork is automatically created here unless you choose another art layer.
	Colour Art layer: A default art layer. This layer displays strokes by default.
	Underlay Art layer: Must be activated in the Preferences to be seen. The bottommost art layer.

Although art layers have specific names, this is mostly a guide. Art layers can be used creatively outside of their suggested use.

Where do you use art layers?

For simple scenes, art layers are not always necessary, but they can be extremely useful for the following tasks:

Paperless animation: 
Separating the line and colour art in a paperless animation can allow for easy separation when it comes to editing or applying effects and overrides. 

The character below has been separated onto Colour Art and Line Art layers for easier editing.

All layers	Line Art layer	Colour Art layer

Related articles:

• How do I apply ‘Create Colour Art from Line Art’ to multiple frames?
• How do I paint multiple frames at a time?

Rigging: 
One of the most common uses for art layers in Harmony. Art layers allow artwork within drawings to be manipulated and adjusted without losing the overall effect of animation and nodes. Common uses in rigging include invert cutting, patching, and overlay artwork. 

The rigged hand below has been separated into multiple art layers so the character can easily ‘hold’ objects between its fingers, and so that the hand can be patched onto the arm.

All layers	Overlay  Art layer	Line  Art layer	Colour  Art layer	Underlay Art layer

Related articles:

• How does the Auto-Patch node work?
• How do I mask one part inside another?
• Why is there a thin line between my layers in the Render view?

Compositing: 
Similar to what was mentioned above with paperless, the separation of art on art layers can make compositing much simpler, as elements can be treated separately without using any heavy systems to divide colours and objects.

The fire below has been separated into art layers to make it easier to apply certain effects to specific elements.

All layers	Overlay Art layer	Line Art layer

Other related articles

The following articles include tips and tricks related to the art layers and their use:

• How do I edit multiple art layers at the same time?
• How do I convert a layer to bitmap or vector?