Movie layers can be used to paint or modify individual frames of a movie file. You could use movie layers to construct hand drawn animation a frame at a time, or to add paint or image processing effects to specific frames in an existing movie file. Movie layers are a new feature in v4 that replace the functionality associated with the old canvas movie features available in earlier versions of Studio Artist. This tip will discuss how to work with movie layers in Studio Artist 4.

Movie layers associate a Quicktime movie file with a specific canvas layer. You can have multiple movie layers in the canvas as a part of the overall layer stack. Any specific movie layer can be played in real time in the canvas by using the movie transport controls located at the bottom of the Layer palette. A composited stack of multiple movie layers cannot currently be played back in real time. But you could flatten the layer stack to a composited output movie and then play that movie output in real time.

The movie transport controls (shown below) appear at the bottom of the Layer palette whenever your current working layer is a movie layer. The transport controls vanish if your current working layer is not a movie layer.

You can use the transport control buttons to move to the beginning or end of the movie file, play the movie forward or in reverse, stop a playing movie, and record over an existing frame or insert a new frame. The frame counter shows the current frame (its frame 1 in the screenshot above). You can click on the up/down arrows to single step the current frame forward or backwards.

You can also use arrow keys to reposition the current frame time if the canvas is the current keyboard focus. Up/down keys single step forward/backwards. Left/right keys move to the beginning or the end of the movie file. The +/- keys also single step forwards/backwards.

You can think of a movie layer as being composed of an image buffer directly associated with the layer and a movie file sitting on disk. When you playback a given movie layer or single step through it’s frames using the layer movie transport controls you are loading the layer’s image buffer with a particular frame image from the movie file on disk. Any changes you make while working with the layer in Studio Artist are made to the image buffer associated with the layer, not to the actual movie sitting on disk. You need to explicitly record any changes you make to the image buffer associated with the movie layer back into the movie file on disk if you want those changes to be stored in the movie file.

In order to record a modified frame image into the movie file associated with a given movie layer you need to record your modified canvas into a given frame position. To record overwrite an existing frame you can either press the R (record) button in the layer movie transport or you can use the appropriate Canvas : Movie Layer menu command.

You can also insert a new frame rather than recording over an existing frame. To insert a new frame after the current frame position you can either shift click the R button in the layer movie transport controls, or you can use the appropriate Canvas : Movie Layer menu command.

Building an animation from scratch

You can use a movie layer to build hand painted animation from scratch.  To start out you need to first start a new movie layer or convert your existing layer to a movie layer.  You can use the appropriate Canvas : Movie Layer menu command to do that. In either case you’ll be asked to name a new movie file on your hard disk, which will be the movie file associated with the movie layer you are generating.

Once you have your working movie layer, you can then start generating your individual frame images. After generating your first frame image, you can press the record button to record the current contents of the movie layer’s image buffer into the first frame of the movie layer’s associated movie file.  You can then generate your second frame image.  You will need to insert a new frame after your first frame, which you can do by shift clicking the record button. Shift clicking the record button will insert a new frame after the current frame position. There are also Canvas : Movie Layer menu commands for both of these operations (that include command key options to run them).

You will then continue to generate new frame images one at a time and insert them into the associated movie file as new frames to build up your desired animation. You can use the movie transport controls at any time to playback your recorded movie file changes in real time. You can also retouch previous frames or add additional painting to previous frames if building up animation from scratch.

There are additional Canvas : Movie Layer menu commands to insert blank space between each of the frames of the movie in your movie layer. So you could construct a series of key frames, then insert blank frames between each key frame, and then build intermediate animation images between the previously drawn keyframes.

Canvas Movie Onion Skin

There are canvas movie onion skin options to help you build intermediate animation frames. You can specify 2 different onion skins, which could be positioned before and after the current frame, or both before or after the current frame at different frame times. By onion skin we mean a partially transparent view of another frame time image(s) displayed on top of the current frame image that is used as a drawing reference for building up animation.

An additional canvas movie onion skin toolbar appears in the Layer palette below the movie transport control toolbar if you turn on the canvas movie onion skin option. There’s a Canvas Movie Onion Skin Toolbar onion skin preference that turns on or off the display of the Layer palette onion skin toolbar, so that  preference option needs to be turned on to use this feature.

You can use the Canvas : Onion Skin : Toggle Onion Skin menu (and it’s associated command key option) to toggle the onion skin view on or off. When the canvas movie onion skin option is toggled on then the onion skin toolbar control become active. There are 2 check boxes to turn on or off each of the 2 onion skin views. The associated numeric fields allow you to specify the number of frames before and after the current frame for the 2 onion skin offset views. By using a negative number for the frame offset you can move the onion skin offset to the opposite side of the current frame (for example -1 for the before offset moves it to after 1 frame).

You could potentially work off of a second loaded source movie file if you wished by using the source onion skin option. The canvas movie onion skin is useful for building new frames off of previously drawn frame images. The source onion skin is useful if you are hand roto-scoping a source movie in some cartoon or paint style.

Studio Artist also includes many additional features for automatically rotoscoping source movies in an endless variety of different paint or cartoon animation styles.  This is discussed in more detail in the section on ‘when not to use movie layers’ at the end of this tip.

Flattening a Movie Layer

Any edits you make to a movie layer are stored as non-destructive non-linear frame edits within the associated movie file. For example, suppose you record over a given frame 5 times over the course of building up an animation. Each of those 5 new frame images is added to the associated movie’s media track, and then a non linear edit performed to insert the new frame data into the appropriate frame time position in the movie’s video playback track.

So over the course of building up an animation you can potentially build up a lot of extraneous media track frames. Also, new recorded frames are added as animation codec uncompressed frame data with no time compression.  After generating a finished animation you may wish to flatten the associated movie file for optimal compression and file size.

There’s a Canvas : Movie Layer menu command to Save a Flattened Canvas Movie as.  You can use this menu command to generate a new flattened movie file that gets rid of any extraneous media track frames that are no longer used. The flattened movie output is also compressed with your current File : Movie Codec Settings menu dialog settings.

Saving a flattened canvas movie also allows you to composite multiple movie layers into a single playable flattened movie file. So flatten refers to potentially flattening the Studio Artist layers as well as flattening the internal media frames stored in the movie file internally.

The current view mode for layers is used when flattening a canvas movie. This basically means that whatever you see displayed on the screen is what is going to be generated for the flattened movie file. So if you want to only flatten the current layer and not a composted view make sure you are in view current layer mode. If you want to flatten multiple layers into a single flattened movie file use the view all mode.

Movie Layer Settings

There are some additional Canvas Movie Layer : Settings menu flag options that are useful when working with movie layers.

Loop Play causes the movie layers to loop during playback if the option is checked. If the option is unchecked then playback stops at the end of the movie.

Advance on Record will automatically advance the current frame position after recording a frame if the option is checked. This option is useful if you are sequentially moving through the frames of a movie layer adding some additional painted feature to each frame.

Synch to Source synches the movie layer(s) to the current source movie frame position if checked.

Synch Layers synches the current frame position of multiple movie layers if checked. If unchecked then different movie layers could be positioned independently to different frame positions.

When not to use movie layers

Movie layers are really designed to build hand drawn animation frame by frame, or to perform touch up or editing on individual frames in a movie.

If your goal is to process an entire existing movie file with a Studio Artist effect you are better off not using movie layers. Instead, you would record a Paint Action Sequence (PASeq) that generates the particular effect you want to process you movie file with. You could then use one of the Action menus to process your movie file with the PASeq.

Here’s a tip that talks in more detail about processing a movie with a paint action sequence.

An alternative approach to generating hand drawn animation is to work with a paint action sequence and build the animation there. You can record a series of individual paint steps in the PASeq. You can then use sequential keyframing in the PASeq timeline editor to record additional keyframes for an animation. You can then use the keyframe animation functionality of the PASeq timeline to generate interpolated animation off of your recorded PASeq keyframes. This approach could potentially save you a lot of drawing time as opposed to if you hand draw each individual frame from scratch.

Individual sketches or paintings can also be encapsulated into a single PASeq action step. A series of these encapsulated paintings can then be keyframe interpolated to generate an animation. An advantage of encapsulated keyframe animation is that an arbitrary number of paint strokes can be used for each keyframe sketch or painting. With sequential keyframing you typically have one PASeq action step for each individual paint stroke. But an advantage of sequential kayframing is that you can use different presets to build up the sketch or painting (as opposed to a single one which would be the case for an encapsulated keyframe animation). Of course you could combine together different encapsulated PASeq action steps in one PASeq to build an encapsulated keyframe animation using different paint presets.

Here’s a tip that talks about encapsulated keyframe animation.

Movie layers are a special kind of Studio Artist layer. The layer is associated with a movie file on your hard disk. A movie layer still contains the normal raster frame buffer and bezier path frame associated with all layers.  But the movie layer also contains a reference to it’s associated movie file.

You can make a new movie layer, convert a normal layer into a movie layer, or load an existing movie file as a movie layer by using the appropriate Canvas : Movie Layer menu commands. If you load an existing movie as a movie layer it needs to be the same size as the existing canvas or it will not load. You can always use the File : Import : Open Movie as New Canvas Movie menu, this will delete the current canvas and construct a new one of the appropriate size to display the opened movie as a new movie layer.

When a movie layer is the current layer a set of movie transport controls become available at the bottom of the Layers palette. You can use those transport controls to play the movie in the main canvas, or to access individual frames in the movie file. When you play the movie or adjust the current frame in the movie transport the movie layer’s image buffer is updated to reflect the contents of the movie at that frame number.

When you paint or otherwise process a movie layer, the editing changes are being made to the image frame buffer associated with the layer. The changes are not actually recorded into the associated movie file until you record the changes. You can use the R (record) button in the movie layer transport to overwrite the current frame in the movie file with the contents of the movie layer’s frame buffer. Shift clicking the R button will insert a new frame as opposed to overwriting the existing frame.

You can also use the Canvas : Movie Layer editing menus to perform movie edits like record over a frame,  insert a new frame, delete a frame, etc.

Any movie layer editing changes are made to the associated movie file when the edit is performed. However, the editing changes are made by adding the new frames to the movies media track and then adding an edit to it’s associated video track. This means that the old frame information is still in the media track of the movie.

The new frames are also not time compressed in any way since we need to add newly recorded frame edits as image frames to avoid problems associated with adding arbitrary frames to some image compression codecs.  Because of this, you may wish to generate a flattened movie file after you are finishing editing. A flattened movie file will only contains the actual media frames used in the final movie and the frames will also be time compressed based on whatever is your current movie compression codec.

Canvas Movie Onion Skin

There’s an additional onion skin toolbar that can be displayed in the layer palette when working with movie layers. The controls are associated with the Canvas Movie Onion Skin option, and will not appear it that is not the current Onion Skin Type.

To make it accessable, you need to set the Canvas Movie Onion Skin Toolbar preference to ‘in Layer Palette’.

An onion skin refers to a semi-transparent guide image. You can adjust the onion skin transparency using the Onion Mix % preference. Onion skins are useful to use as drawing guides when creating hand drawn animation.

The Canvas Movie onion skin type can be used to show an onion skin view of 2 different adjacent movie frames. Typically one chooses a frame before the current frame and after the current frame.  The number fields next to before and after refer to the # of frames before and after the current frame. If you want to use 2 frames on the same side of the current frame you could set one of the options to a negative frame number.

For more detailed information about movie layers try this additional tip.

The Studio Artist 4 canvas supports multiple layers. This post will discuss the various features associated with layers.

Layers Overview

Each layer consists of a RGB image, an alpha channel, and a Bezier path frame. The RGB image is a raster frame buffer that you paint into. The associated alpha channel can act as an integral mask. The Bezier path frame stores Bezier paths associate with the layer. If the layer is a movie layer then it also contains a reference to it’s associated movie file.

You can have as many layers as you wish, but be aware that each additional layer takes up system memory. Each layer has an associated name, status, compositing option, and transparency option.

The canvas can be viewed in 2 different modes. They are the ‘View All’ and ‘Current Layer’ view modes. The Current Layer view mode only displays the current layer.  The View All mode displays the entire composted layer stack.

You can switch between view modes by using the view icon popup in the main operation toolbar. Or you can use the View All menu flag in the main Canvas : Layer menu to toggle between the 2 different view modes. This menu flag also has an associated menu command key.

A layer’s status, composite, and transparency settings will only be active if the canvas is being viewed in ‘View All’ mode. If a layer’s status is on, then the layer will be active and used to generate the overall composited layer stack view. If the layer’s status is off, then it is muted and will not be used when computing the composited layer stack view.

Muted layers can be used as non-displayed temporary storage buffers in paint action sequences (PASeq) that use multiple layers, to store masks, to store textures, to store stereo disparity maps, or for whatever additional uses you come up with. Muted layers are displayed when in Current Layer view mode (if they are the current layer).

A layer’s Compositing setting refers to the particular compositing algorithm used to combine it into the accumulated view all layer stack display. A few of the different compositing options are shown in the screen snap above. Layers are composited in order from top to bottom of the layer stack list. Layers, like all list elements in Studio Artist, are always applied from top to bottom. 

Composite refers to how the layer is algorithmically added to the layer stack view. A compositing algorithm takes 2 images as input (the layer being composited and the view being constructed) and generates a single image as output (the view being constructed). An example of min compositing in view all mode is shown below. Layer 1 contains a painted blue numeral 1, layer 2 contains 4 painted red numerals 2.

Alpha Channels

Each individual layer also contains an integral alpha channel. You can think of an alpha channel as being a mask that provides a percent coverage value for each pixel in a RGB raster image.  Studio Artist has a very flexible alpha implementation. You can turn alpha compositing on or off for the layer stack by using the Canvas : Alpha : Enable for View menu flag.

If you are just doing traditional painting or photo effect image processing you are probably better off leaving alpha compositing turned off. For more information on working with alpha in Studio Artist 4 check out this post.

Movie Layers

Movie layers are how you can associated movie files with specific layers in v4. You can have as many movie layers as you wish. Movie layers contain a reference to a specific movie file stored on your hard disk (as opposed to the contents of the movie being physically stored in the layer itself). You can play or move between different frames of a movie layer by using the movie transport that appears at the bottom of the Layer palette when a movie layer is the current layer.

Movie layers replace the old canvas movie feature available in previous versions of Studio Artist. The old canvas movie was a virtual layer that sat on top of the canvas layer stack, while the new Movie Layer feature allows for multiple movie files to be in different layers in the overall canvas layer stack.

There are a number of different movie layer commands accessible in the main Canvas menu. You can overwrite record to an existing frame, insert new frames, delete frames, etc.

A movie layer contains a normal layer image buffer and a reference to it’s associated quicktime movie file. When you paint on an individual movie layer, you need to record the paint changes to the current frame before you move to a new frame, or the changes will be lost.

Editing changes made to a movie layer’s associated movie file are non-linear editing changes, where a new frame is inserted into the movie media track and an edit change is made to the video track that references the new media frame. New frames are inserted into the media track as non-compressed frames. When you are done editing a movie layer you will want to flatten the associated movie, which you can do using the Save Flattened Canvas Movie as menu command. Flattening a movie re-compresses all of it’s associated frames using the current application movie compression settings (File : Movie Codec Settings dialog).

Studio Artist has a very flexible and configurable display environment, so you are free to utilize the alpha layer or turn off alpha view and ignore it depending on your workflow needs. You could also turn off alpha view and use it for non-conventional uses, like as an additional buffer to store a temporary selection mask or as a depth buffer or a spatial modulator for an effect. Some other graphics programs you may be familiar with will always have alpha view enabled, or even hide the fact that it is being used.  

One reason why Studio Artist provides the flexibility is that we allow for wet paint mixing visual effects that are not very compatable with traditional approach to alpha compositing. So if you are not doing a lot of layer compositing effects that require alpha to achieve, you are probably better off turning it off and enjoying the amazing wet smear effects you can create in individual layers.

All of Studio Artist’s various operation mode effects also have internal Mix and Composite parameter settings as a part of the individual effects, so things that would typically require multiple layers to achieve in other graphics programs can be done in place in a single layer.

Layer Display View

Studio Artist’s view system also allows you to view the current layer only, or to view all layers. Again, this is more flexible than other paint programs you may have used in the past.

You also have the ability to turn off the status of individual layers. If you do this then they won’t show up when the display is set to view all. This allows them to be used as temporary buffers in PASeq effects or to store different versions of a drawing while working. Layer compositing controls will only affect the displayed view when you are in View All mode, they are ignored when in View Current Layer mode.

You can use the Canvas : Layer ; View All check menu to toggle view all mode on or off.

You can also use the icon popup in the main operation toolbar to switch between the 2 view modes..  

Layer Alpha View

The individual menu commands associated with alpha are accessible in the main Canvas : Alpha menu. If you want alpha to be enabled for view all mode in the canvas you need to turn on the Alpha : Enable for View check menu. If you want the paint synthesizer to draw in the alpha channel when painting you need to turn on the Alpha : Paint Synth Alpha Enable check menu.

When alpha view is enabled, a layer’s alpha channel acts as a mask for the color pixels of the layer. If an alpha value for a pixel is full off (a value of 0), then none of the color information for the pixel will show through. If the alpha value is set to 50% (a value of 127), then the color information in the pixel is mixed with the color information in that pixel location in the previous layer. If the alpha value is set to full on ( a value of 255), then none of the previous color information shine through the mask and the current layer’s color pixel information fully replaces the previous layer that that pixel location.

If the entire layer’s alpha is set to Full Off using the Alpha : Set To : Full Off menu, then the layer will not be seen at all when alpha view is enabled. The color pixels in the layer are still there, and if you disable alpha view you will see that everything drawn in the layer is still there. If the entire layer’s alpha is set to Full On using the Alpha : Set To : Full On menu, then the layer will totally cover over and replace any layers already composited in the view.

Layer Ordering

Studio Artist’s layers are stored in a list in the Layers Palette.

The ordering of the list is the same as all other Studio Artist lists, it goes from top to bottom. This means that layers are composited in the view from the first layer at the top of the list in order to the last layer at the bottom of the list.

There is a default background color that is specified using one of the check menus in the Alpha : Background menu shown below.

If all of the layers in View All mode had their alpha channels set to full off then the only thing you would see in the view with alpha enabled would be the default background color you had specified,black in the case of the screen snap shown above. So, if you ever end up in a confusing situation where you see a black screen and you didn’t manually set the layer to black, that probably means you have alpha view enabled and your layer’s alpha channel is set to full off.

An easy way to debug this is to turn off alpha view and switch to the current layer view and see if the color pixels in your layer reappears in the view. Again, unless you have a definite reason to be working with alpha channels for masking purposes i would suggest keeping the alpha view disabled to avoid potential confusion. For generic digital painting or photo manipulation in a single layer there’s really no reason to be working with alpha.