Introduction

Welcome to combustion™—paint animation and visual effects on your desktop. combustion contains all the tools and visual interactivity you need to produce compelling images.

This chapter explains:

About This User's Guide

combustion provides unified painting, animation, and 2D/3D compositing, all within an intuitive workflow environment. This guide attempts to explain all the features in this powerful software. It is designed to provide information both by topic and in the order of a typical workflow.

If you are an experienced paint or effects artist, you can use the guide for reference, turning directly to sections of specific interest.

If you are new to some aspects of digital paint animation and compositing, you can browse the chapters from start to finish, read about the tools, and follow the examples at your own pace.

Learning combustion

The documentation for combustion includes:

 

Using This Guide with Macintosh and Windows

You can use this guide when working with combustion on a Windows® or Macintosh® system. For commands that vary depending on your system's platform, both commands are documented; however, most of the screen shots in this guide show combustion on a Windows platform. If you are using a Macintosh, some elements may vary slightly.

 

Notation Conventions

The following style conventions are used in this guide.

Convention:
Example:

Filenames or paths, and values that you type in a field, are in italics.

Load a file from the Particle Libraries folder.

Menu selections are indicated by dividing vertical lines

Choose Operators | Stylize | Bump Map.

Key Features

combustion offers a powerful suite of paint and compositing tools, integrated into a single creative environment.

The following sections describe some of the key features in combustion.

Workflow

Interface

Compositing

Particles

Paint

Selections

Animation

Keying

Color Correction

Tracker

Film Tools

Audio

RenderQueue

Supported Files

Including:

See Importing Footage

What's New in Version 2.0

Here is a list of the new features in combustion 2.0.

For a list of changes, see What's Changed in Version 2.0.

What's Changed in Version 2.0

Here is a list of some changed features in combustion 2.0. Other smaller improvements are not listed here.

Quick Tour

This Quick Tour provides you with basic combustion functions and some of its workflow patterns.

This chapter introduces:

Getting Started

The very first step in starting a new project is to bring footage into a workspace. The workspace is the file that stores information that references your footage, composite order and layout, animation, and operators. Like a document file in a word processing system, a workspace can be saved, reopened, and edited at any time.

The easiest way to bring footage into a workspace is by using the Open command. You can choose from many file formats for opening footage into combustion. These include Video for Windows (AVI), QuickTime® (MOV), TARGA®, and many others.

For more information about getting started, see Starting a Workspace.

To open footage into a new composite:
  1. Choose File | Open, or press Ctrl+O (Windows) or Command+O (Macintosh).

    2. The Open file browser appears.

  2. Navigate to the folder containing the clip you want to open, select the clip, and then click OK.

    3. Note: You can scrub the clips in Thumbnails view. Ctrl-click (Windows) or Command-click (Macintosh) to select multiple clips. Selected clips appear at the bottom of the file browser. To remove a selected clip, double-click it in the bottom part of the browser.

    The Open Footage dialog appears.

  3. Click Composite - 2D and then click OK.

    4. The footage is imported into a new 2D composite. The size and duration are set to the size and duration of the first file selected.

    A new layer (or layers) containing the selected footage appears in the composite. The footage appears in the active viewport.

Managing Layers and Operators

When you import footage, it becomes a layer in the selected composite. You can view the relationships between footage, layers, and the composite by navigating in the Workspace panel or in Schematic view.

To composite these two layers together, you can add a Keyer to the Doggie layer. You can do this in Schematic view or the Workspace panel.

For more information about layers, see Compositing.

Expand the highest level branch in the Workspace panel to see the composite.

Expand the composite to see the layers contained in the composite.

Expand a layer to see that layer's footage (and operators, if there are any).

Arranging Layers in the Stack

Layers higher up in the Workspace panel stack appear in front of layers lower down. You can rearrange layer positions at any time by dragging them to their new position.

When the Z-position of the layers in a 3D composite is the same, the layer higher in the stack takes precedence. In 2D composites, you do not have Z-position. You also do not have lights or the camera.

Toggling Layer Visibility

Hide a layer to temporarily see the layers beneath it. You can hide a layer in a composite by clicking the icon to the left of the layer.

Note: You can also toggle the visibility for composites, operators, and footage by clicking their icon.

 

Compositing

You can use imported footage as layers in composites.

Compositing is the process of combining layers together to form one final image. It can be as simple as placing one partially transparent image over another one or creating a split-screen effect. It can be as complicated as combining blue-screen talent, multiple alpha-keyed CG layers, effects, backgrounds, and text to create a science-fiction action sequence.

For more information, see Compositing.

 

Positioning, Scaling, Rotating, and Shearing

One of the simplest forms of compositing involves scaling, rotating, and positioning layers so that multiple layers are visible simultaneously and form one final result.

In the following example, we orient copies of one layer to create a composite comprised of multiple layers.

After scaling, rotating, and positioning copies of the layer, the scene is transformed into something more dynamic.

To orient layers in a composite:
  1. After importing footage into a composite, expand the composite in the Workspace panel, and select the layer.

    2. The layer is highlighted in the active viewport.

  2. Click the Toolbar tab.
  3. Use the following tools to transform the selected layers.

    Use:
    To:

    Move the selected layer in the active viewport. Use the tool options to constrain the movement along the X-, Y-, or Z-axis.

    Rotate the selected layer in the active viewport. Use the tool options to constrain the rotation around the X-, Y-, or Z-axis.

    Scale the selected layer in the active viewport. Use the tool options to constrain the scaling along the X-, Y-, or Z-axis.

    Shear the selected layer in the active viewport. Use the tool options to constrain shearing to the X-, Y-, or Z-axis.

    Move the selected layer's pivot point in the active viewport. Use the tool options to constrain the movement along the X-, Y-, or Z-axis.

    4. Note: You can also double-click the button to type in exact transform values.

  4. Click the Transform button on the Composite Controls panel to fine-tune all the transforms.

Keying and Masking

Use keying and masking techniques to make areas of a layer transparent and see through the layer to layers behind it.

 

 

Keying Out a Color

You typically use keying in conjunction with clips shot in front of blue or green screens. The keying process removes the specified color (typically shades of blue or green) allowing you to see through to the layers underneath. For more information on keying techniques, see Creating Alpha Channels with Keyers and Discreet Keyer.

In the following example, the footage of a couple is shot in front of a green screen so it can be composited over a background depicting a busy tavern.

To create the final composite, first we combine the layers so that the front layer is in front of the back layer.

After the layers are combined, we use a keyer to key out the green from the front layer.

To pull a green-screen key:
  1. Import a front layer (shot in front of a green screen) and a back layer into the current composite.
  2. In the Workspace panel, arrange the front layer so that it is in front of the back layer, then select the front layer.

  3. Choose Operators | Keying | Linear Keyer.

    4. The Linear Keyer Controls panel appears.

    Note: When using the Linear Keyer, it is easiest to attain good results when Feedback is enabled. This lets you see the way the key changes on-the-fly as you change keyer parameters.

  4. Click the color picker , then click anywhere in the solid background color to sample the background green.

  5. Drag the Tolerance value until the background color disappears. A value around 20-25% often produces good results.

    6. Warning: When the Tolerance value passes a certain level, you may begin keying out portions of the image you want to keep.

  6. You can remove more of the unwanted background color from the matte using the Cleanup slider. Usually a Cleanup value of 100% works well.
  7. After you finish adjusting the key controls, the key color is removed and the front layer appears composited over the back layer.

Masking Layers

Masks perform a similar function as keyers, except you use masks to define the shape of transparent areas of layers. For more information, see Using Masks.

In the following example, a mask is used to isolate the subject in the foreground layer so it can be composited over the background layer.

To create a rectangular mask:
  1. Import a front layer and a back layer into the current composite.
  2. In the Workspace panel, arrange the front layer so that it is in front of the back layer, then select the front layer.

  3. Choose Operators | Mask | Rectangular Mask.

    4. The Rectangular Mask operator opens and a default size rectangle mask is added to the layer.

  4. Click the Toolbar tab, and then click the Arrow tool .
  5. In the viewport, use the bounding box to adjust the size and rotation of the mask. For information on sizing and rotating with a bounding box, see Editing Object Transform Properties.
  6. Click the Modes button on the Mask Controls panel.
  7. The Modes controls appear.

  8. Set the mask Combine Mode to Replace.
  9. If necessary, you can feather the mask edge. For more control over the feathering and softness, use egde gradients.

  10. Click Invert to invert a mask or adjust the opacity slider to vary the mask's opacity.

  11. Return to the composite to see the results of the masking operation: double-click the composite in the Workspace panel or click the Back button.

 

Nesting Layers and Composites

Use nesting to combine layers and composites in one workspace. For information on nesting, see Working with Nested Composites.

Creating Nested Layers

Nesting layers means taking selected layers (or a composite) and grouping them together. In the Motorcycle Composite illustration, three layers are composited and nested. Once the layers are nested, transforms can be applied to the result.

Note: Layer 1 in the composite is a copy of Layer 3 that has been masked to isolate the subjects from the background.

In the following illustration, the Workspace panel on the left shows the separate layers that were used to build the composite. In the Workspace panel on the right, you see that the three layers are inserted into a Nested Layer, which, in turn, is rotated and scaled (thereby transforming all nested layers simultaneously).

To nest layers:
  1. In the Workspace panel, select the layers you want to nest.
  2. Choose Object | Nesting.

    3. The Nesting Options dialog appears.

  3. Enter a name for the nested layers in the Composite Name field.
  4. Click Selected Layers, and then click OK.

    5. The layers are grouped together.

 

 

Applying Operators

An operator modifies a layer or a composite. For instance, you can use a Keyer operator to key out a portion of a layer, and then use a Color Corrector operator to color match the layer to the background.

If, however, you drag the Color Corrector operator below the Keyer, the key is created taking into account the changes to the layer's color.

You can place an operator anywhere in the branch—on a layer, on the output of a nested composite, or on the output of the entire branch.

At any point in your project, you can move an operator to another place in the process tree, modify its parameters, change its animation, copy it, or simply delete it.

For more information, see Applying Operators.

 

Applying an Operator to a Layer

You can add operators to any layer in the workspace.

To apply an operator to a layer:
  1. Double-click a composite to make it current.
  2. In the current composite, select a layer.
  3. From the Operators menu, choose an operator.

    4. The operator controls appear. The operator is applied to the selected layer over its entire duration.

  4. Adjust the operator controls.

Keyframing

You can animate a layer by setting at least two keyframes for the layer's categories at different times. A keyframe is a point in time that records any change to a layer in your workspace.

Before you can create keyframes, you have to enable the Animate button. For more information on animating, see Keyframing.

To animate a layer using keyframes:
  1. Enable the Animate button (A).

  2. Select a layer (for instance, we select the Vanes layer from the illustration above to rotate the windmill's vanes).
  3. Press the Home key to move to the first frame of the animation.
  4. Use the Transform controls to set a rotation category at the first frame of the animation. For instance, set the Z Rotation to 130°.
  5. Click the Timeline tab, expand the layer that you want to animate, and then expand the Transformation category.

    6. You can see a keyframe has been set for the Z Position channel.

  6. Press the End key to move to the last frame.
  7. Change the value for the Z Rotation channel. To do so, click and drag your cursor over the Z Rotation value in the Timeline list, or click the Composite Controls tab and use the Transform controls.

    8. A keyframe is set at the last frame. The values between the keyframes are determined automatically using interpolation.

  8. Click the Graph button to see the shape of the interpolated animation curve.

  9. Move back to the first frame, and then press the Play button on the playback controls to watch the animation.

    10. Note: You can adjust the shape of the animation curve between keyframes to create customized animations.

    For information on adjusting animation curves, see Editing Keyframes and Animation Curves.

Animating with Motion Paths

Once you create two (or more) keyframes for a layer, you can adjust the way the layer moves by changing the shape of the motion path.

To create a motion path for a layer in a composite:
  1. In the Workspace panel, select the layer you want to animate.
  2. Use the playback controls to move to the first frame (or press Home).

    3. The motion path starts here.

  3. Enable the Animate button (A).

  4. Click the Toolbar tab, and then click the Arrow tool .
  5. In the active viewport, drag the selected layer to its starting position.
  6. Use the playback controls to move to the frame where you want to create a second keyframe.

  7. Drag the layer to its new location (you can also rotate, scale, or adjust any other channel).

    8. A keyframe is created, and the layer's motion path appears.

  8. Advance (or go back) to another frame, and move the layer again to create another keyframe.

    9. The keyframes are joined by a motion path.

  9. Continue adding keyframes until you achieve a result you like.
  10. To change the shape of the motion path between keyframes, drag the tangent handles at a keyframe.

You can also adjust the speed along the motion path using the Speed channel.

 

 

Copying and Pasting Keyframes

When creating animations with multiple layers, you can save time by copying and pasting keyframes between the layers.

To copy and paste keyframes from one layer to another:
  1. In the Workspace panel (or active viewport), select the layer that contains the keyframes you want to cut or copy.
  2. Click the Timeline tab.
  3. In the Timeline, expand the category with the keyframes you want to cut or copy, then select the channel.

    4. The keyframes appear in the Timeline.

  4. Draw a rectangle selection around all the keyframes you want to cut or copy.
  5. Choose Edit | Copy or press Ctrl+C (Windows) or Command+C (Macintosh).
  6. Select the channel to which you want to paste the keyframes.
  7. Position the Timeline cursor where you want the first keyframe to be pasted.
  8. Choose Edit | Paste or press Ctrl+V (Windows) or Command+V (Macintosh).

    9. The keyframes are pasted into the selected channel starting at the location of the Timeline cursor.

sing the Paint Tools

Paint is an interactive, vector-based and object-oriented drawing operator that you apply to a layer as you would other operators. It allows you to perform a wide range of painting tasks, from simple retouching, to motion tracking, to full cartoon animation. As with other painting-type software packages, there are tools for creating paint strokes, geometric shapes, text, selections, and masks.

Unlike other packages, every element you draw and create in the Paint operator is non-destructive. As with all other operators in combustion, at any point in the compositing process, you can go back into the Paint operator and modify the objects.

For more information on Paint, see Introduction to Paint.

In the following example, we use the Paint tools to create a banner with an opacity gradient and a text caption with a drop shadow over a composite.

 

 

Step 1: Creating a Paint Object

You use the painting tools to create Paint objects such as rectangles and ellipses, text, and brush strokes. In this example, we create a filled rectangle to use as a banner in the composite.

To create a Paint object:
  1. Select the layer that you want to "paint" and then choose Operators | Paint.

    2. A Paint operator is added to the layer.

  2. Press the Home key to make sure you are positioned over the animation's first frame.
  3. Click the Toolbar tab.
  4. Click the lower right corner of the Rectangle tool to create a filled rectangle. (Click the tool again to toggle between filled and stroked mode.)
  5. Draw a rectangle over the lower left portion of the image as illustrated below.

  6. Click the Arrow tool and click the rectangle to select it.
  7. In the Paint Controls panel, click the Modes button, then click the foreground color box to specify the fill color for the rectangle.

    8. The Pick Color dialog appears.

  8. Select a bright shade of red and click OK.

    9. The rectangle in the viewport turns red.

  9. Click the Gradient color mode button.

  10. Click the Gradient button to access the Gradient controls.

  11. Click the Opacity gradient bar to add an opacity gradient tag, then drag the new tag all the way to the left.
  12. Click the Opacity gradient bar again, then drag the new tag all the way to the right.
  13. With the right opacity gradient tag selected, drag the opacity slider to 0%.

    14. The red rectangle turns progressively transparent.

Step 2: Adding a Caption

Now we need to add a text caption to the banner.

To add a text caption:
  1. On the Toolbar, click the Text tool .

    2. Text tool options appear.

  2. Set the text properties to the following values:
  3. Draw a text box on the viewport over the banner and type:

    4. My Composite.

  4. Click the Arrow tool .

    5. A text object is created and added to the composite.

  5. Position the text object so it is over the filled rectangle object.

 

 

Step 3: Creating the Drop Shadow

To create a sense of depth, we add a drop shadow to the text caption.

To add a drop shadow:
  1. With the text object selected, click the Shadow button to access the Shadow controls.

  2. Click Enable Shadow to activate the drop shadow controls, then create a drop shadow using the following values:
  3. Click the Color box and pick a bright yellow shade from the Pick Color dialog.

    4. At this point, the composite should resemble the following:

Step 4: Extending Object Duration

By default, a new object exists only on the frame upon which you create it (therefore, it has a one-frame duration). You have to extend the length of your Paint objects so they last the entire duration of the animation.

To change object duration:
  1. Click the Timeline tab to view the Paint objects. You have to extend their duration to the end of the composite.

  2. Select the objects. In this example, we select the My Composite object and the Filled Rectangle object.
  3. Press the End key to move to the last frame of the sequence.
  4. Press the period (.) key on the keyboard to extend the object length for the duration of the sequence.

    5. Note: You can also set object duration using the Default Object Duration setting in the Paint controls. For more information on object duration and other Paint controls, see Introduction to Paint.

     

     

Step 5: Playing the Animation

Now that all the elements are in place, we are ready to play the animation.

To play an animation:
  1. Click the Workspace tab.
  2. To display the composite in the active viewport, double-click the composite in the Workspace panel or click the Back button.

    3. You exit Paint and return to the composite.

  3. Click the Play button to play through the animation.

 

Working with Audio

With the scratch-track audio capabilities of combustion, you can import audio, link audio to clips, slip audio to sync to your composite, and save audio in workspaces for reference and organization.

For more information, see Audio.

Note: Supported file formats are WAV, AIFF, QuickTime embedded audio, and AVI embedded audio.

To import and play back audio:
  1. Click the Audio tab.
  2. In the Audio panel, click the Browse button.

    3. The Open Audio dialog appears.

  3. Navigate to the audio clip, select it, then click OK.

    4. The clip is imported. An audio waveform appears on the Audio panel.

  4. Enable Play Region to restrict playback to a portion of the audio file.
  5. Click the Play button to play the audio. Click the Stop button to stop audio playback.
  6. Click the Timeline tab.
  7. Enable Waveform in the Timeline control buttons.

  8. Audio waveforms appear in the Timeline.
  9. Hold down Ctrl+Alt (Windows) or Command+Option (Macintosh), then drag the waveform to change the position of the audio with respect to the layers in your composite.