Animating Knots And SplinesWednesday, February 1, 2017 12:40 AM
Every motor associated with either a set of bones or mesh region contains animatable properties. These properties can be added to the Knots or Splines view for manipulation. Setting key values over time in this view allows you to construct the desired animated behavior.
Click on the image below to watch a video tutorial on how it all works:
Adding/Clearing Animatable Properties
Selecting a bone or region in the scene automatically adds the animatable properties associated with the motor of the selected element into the Knots or Splines view.
If you want to clear the views of animatable properties, simply click on the Broomstick Button:
You can re-add the desired properties by selecting the bone or region again if needed.
The user can expand and shrink how many cells are visible by scrolling the zoom bar.
Jumping to a cell on the current Time/Frame
Click the focus button to display the group of cells closest to the current Time/Frame of the animation.
Key Frame Value Operations
By clicking on a Single Cell in either the Knots or Splines mode, a set of buttons appear on the lower left of the panel:
- Set Key Frame Value This allows the user to set a new key frame value at the time/frame of the selected cell if a key value does not exist. If the cell is already occupied, the current key value can be changed through this button.
- Mathemetical Expression Run a mathemetical expression over all values of this animatable property. This is a powerful feature that allows you to feed existing animated values into a mathematical function crafted by the user. Please read the in depth description of using mathematical expression scripting in the other pages of this site.
Use this mode when you want to set and view where knot values are placed with respect the the time/frame range of the animation clip. Time/Frames that have knot values are marked with a blue node. Cells in between knot values have a red line running through them.
The following operations are available for knot manipulation:
- Delete This removes the knot or group of knots selected by the user. An animated property must have at least 1 knot so this operation always leaves at least 1 knot remaining when run.
- Copy This copies the selected knots.
- Cut This copies and then removes the selected knots, performing a Cut operation.
- Paste This pastes the group of knots copied or cut onto the newly selected cell(s).
- Shift This pops up a panel allowing the user to shift the selected knot values backwards or forwards by a series of frames.
- Retime This allows the user to speed up or slow down a group of selected knots. Retiming is determined by a number serving as the retiming factor. For example, a retime factor of 2.0 will slow down the selected knot animation by 2 times. A retime factor of 0.5 will speed up the selected knot animation by 2 times.
This mode allows the manipulation of animation spline curves. Key Frame knot values are indicated by a red node in the cells. Tangent points are indicated by blue nodes in the cells. You can use the mouse to click and drag both Key Frame and Tangent points in this mode to change how the animation curves behave over time.