Editing Animation Timing with the Dope Sheet
The Dope Sheet is one of the editors in the Animation Panel. It's used to change the timing for animations. Timing is basically "when things happen". For example you might want to change when an animation starts or how long it lasts. The Dope Sheet is specifically aimed at making these sorts of changes. When you edit animation keys with the Dope Sheet you are only changing the frame positions of those keys, not the values. This makes it easy to change animation timing without effecting the values of keys.
Having said that, changing the frame positions of keys can have an effect on the interpolated values between the keys. You might want to check to see how things are looking in the Curve Editor every so often, just to make sure things are as they should be.
In case you're wondering the name "dope sheet" comes from traditional animation. The dope sheet, also known as an exposure sheet, is a document that helps an animator organise their animation and also give instructions to the cameramen who are filming the animation.
The Dope Sheet view shows consists of rows. Each row corresponds to an item in the node list to the left. A row contains all the keys for a corresponding parameter or component of that parameter.
Some of the items in the node list are for the nodes themselves. These rows don't have any keys as, of course, you animate parameters of nodes and not the nodes themselves. You can expand a node item in the list to show the all the animated parameters for that node.
The keys for parameters are shown as white diamonds in the corresponding row in the Dope Sheet view. Some parameters have multiple components, such as vector or colour parameters, and you can set keys on the individual components. In this case the keys in the row for the parameter are coloured yellow. This are special keys called metakeys. You can find out more about metakeys here. If you expand the parameter list item you will see new rows in the Dope Sheet for each component.
Connecting all the keys in a row is bar which is a bit darker than the row background. This is called the range bar. You can double click on the range bar to select all the keys in that row.
Moving keys is the way to change when things happen in an animation. Let's say you have an animation which starts at frame 10, but you want it to start at frame 20. Simply double click on the range bar for the parameter to select all the keys and then drag the keys so the first key is at frame 20.
You also change when particular parts of an animation happen. All you need to do is select the keys relating to that part of the animation and then move them to when you want it to happen.
When you have finished moving any keys that were at the location of a moved key get replaced by the moved key.
To move keys interactively you need to make sure that the Dope Sheet is in the movement mode, rather than one of the scaling modes. This is the default mode for the Dope Sheet but you can change to it by clicking the Move keys button below the editor view:
The Move keys button is on the left
There is a hotkey to switch to movement mode.
You can scale keys to change the length of an animation while still keeping the time between keys in the same proportion. You can stretch all or part of animation out to make it longer or you can squeeze it down to make it shorter. You can scale keys interactively, by selecting keys and dragging them, or more precisely using the Action button. When you are scaling keys interactively you first need to choose a scaling mode (described below) by clicking the appropriate button under the editor view:
Scale about frame mode button in middle,
Scale about center of selected keys mode button on right
There are also hotkeys for changing the scaling mode.
The Dope Sheet has two scaling methods. The first is scaling about the frame cursor. This is the most versatile scaling method. First you move the frame cursor to the location you want scaling to start from. Let's say you want to stretch an animation out:
- Move the frame cursor to the first key.
- Select all the keys you want to scale.
- Drag any of the selected keys to do the scaling.
This will stretch the animation out from the first key.
The other scaling method is scaling about the centre of the selected keys. Scaling will happen about the middle of the keys you've selected. Here's an example:
<mediaplayer width="768" height="250">file:Dopesheet_scale_about_centre.mp4</mediaplayer>
In this movie the frame cursor has been moved to the centre of the keys just to help you see what's happening. The frame cursor has no effect when you scale about the centre of selected keys.
When you have finished scaling any keys that were at the location of a moved key get replaced by the moved key.
You can easily reverse an animation or, in other words, flip it end for end. Reversing is a special form of scaling. There are a couple of ways to reverse an animation.
The easiest way is to use the Action button:
- Select all the the keys.
- Enter -100 in the Action edit field.
- Click the Action button and choose Scale keys from centre of keys.
This will flip the keys "in place" without otherwise changing their timings.
The other way to reverse keys is to scale them interactively. As mentioned above there are two scaling methods in the Dope Sheet - scaling about the frame cursor and scaling about the centre of the selected keys. Whenever you drag past the location you're scaling about the keys will be reversed. For example lets say you're scaling about the frame cursor. You start dragging one of the keys on the right of the frame cursor. If you drag the key to the left side of the frame cursor the animation will be reversed.
You can insert new keys using the Dope Sheet. There are two ways to insert keys. One is to press the Insert key hotkey and then click where you want to insert the key. The other way is to context click where you what to insert the key and then choose Insert key from the context menu.
When a key is inserted it's frame value is taken from the frame location you inserted it at, as you might expect. The value of the key is taken from the interpolated value at that frame. Depending on the interpolation method inserting keys might give unexpected results. You can check the parameter in the Curve Editor just to make sure everything is looking as it should.
You can insert metakeys in parameter rows. When you insert a metakey a new key is also inserted in every component of that parameter.
Copying and pasting keys
You can copy and paste keys in the Dope Sheet. When you paste keys they're inserted at the current frame cursor position. Pasted keys will replace any keys that are at the same frame.
You can also duplicate keys. When you duplicate keys they're inserted one frame past the last existing key.
When you've pasted or duplicated keys the view will move to centre on the newly added keys.
There are currently some limits you need to keep in mind though:
- You can only copy key and paste keys into the row selected in the node list. Even though you can select keys from multiple rows only the keys from the selected row will be copied.
- You can't copy and paste metakeys. If you try to copy metakeys you'll hear a beep.
The Node List is a part of the Terragen interface that shows a list of nodes along the left side of the application window. The Node List generally shows only those nodes that are relevant to the current Layout (e.g. Terrain, Atmosphere). It sometimes includes buttons or other controls that are specific to a particular Layout as well. The Node List is hierarchical and each level is collapsible.
A parameter is an individual setting in a node parameter view which controls some aspect of the node.
A single object or device in the node network which generates or modifies data and may accept input data or create output data or both, depending on its function. Nodes usually have their own settings which control the data they create or how they modify data passing through them. Nodes are connected together in a network to perform work in a network-based user interface. In Terragen 2 nodes are connected together to describe a scene.
A vector is a set of three scalars, normally representing X, Y and Z coordinates. It also commonly represents rotation, where the values are pitch, heading and bank.
Context clicking shows a contextual menu. On Windows this would normally be done with a right click. On OS X this could be a control-click or a right click.