In this example, we will use very basic geometry so that the focus is on how to use the BCS. The base shape is a plane. The weight moves the vertices as if the plane is rotated.
Here is an image showing the path that the front vertex takes. As you can see, its movement is linear.
An inbetween in BCS and Blend Shape terminology is a shape that is reached between the extreme values of a weight. For more information, see 5.3 Inbetween Basics: WeightPositions.
Creating an inbetween in a BCS setup involves the following steps:
Inbetween dataPoints are created with a certain weightPosition or a combination of different weightPositions—just like any other dataPoint. For inbetweens, this means that you have to create a weightPosition on a weight’s value that lies between 0 and 1.
This is done by selecting the weight and creating a new weightPosition using the “Create Weight/WPos” UI section.
In this image, we are about to create an inbetween weightPosition for weight
Since most inbetweens don’t introduce completely new movements but instead alter the main movement created by the dataPoint on position 1, inbetween dataPoints should be “relative” to the otherwise linear main behaviour. This can be achieved by placing the inbetween weightPositions on a sub-layer.
To do this, simply select the inbetween weightPosition and press the ‘>>’ button in the “Weight Settings” UI section:
You can also tweak the transition behaviour by selecting different interpolations for the weightPosition.
This is as easy as creating other dataPoints. Choose the desired position by selecting the appropriate weightPositions and do a “right-click->Create Data Point”.
Upon creating the inbetween dataPoint, the BCS has already created the geometry you can use to model it. In the UI, you can find the dataPoint in the dataPoint list under its dataPoint group. You might have to double-click the group in order to expand it and see the dataPoints. Use the menu item “Data Points->Rebuild DataPoint Name” to convert the names of dataPoints so that they include information about their position.