Configuring Constraints Directly

< Previous | Contents | Manuals Home | Boris FX | Next >

Configuring Constraints Directly

Each tracker has individual constraints that can be used to control the coordinate system, accessed through the Coordinate System Control panel. The *3 button automatically configures these controls for easy use, but you can manually configure them to achieve a much wider variety of effects—if you keep in mind the mental picture of the busy little feet in the coordinate measuring machine. Those feet do whatever you tell them, but are happy to wreak havoc in any axis you do not give them instructions for.

Tip : Use the Constrained  Points  view , discussed below to examine your overall setup and catch mistakes.

As examples of other effects you can achieve, you can use the Target Point capability to constrain two points to be parallel to a coordinate axis, in the same plane (parallel to XY, YZ, or XZ), or to be the same. For example, you can set up two points to be parallel to the X axis image , two other points to be parallel to the floor, and a fifth point to be the origin.

Suppose you have three trackers that you want to define the back wall (Z up coordinate system).

1) Go to the coordinate system control panel

2) If the three trackers are A, B, and C, select B, then hold down ALT (Mac: Command) and click A.

3) Change the constraint type from Unconstrained to Same XZ plane .

4) Select C, and ALT-click (Command) on A, and set it to Same XZ Plane also.

This has nailed down the translation, but rotation only partially—the feet will be busy. You also need to specify another rotation, since B and C can spin freely around A so far (or around the Y axis about any point in the plane).

You might have two other trackers, D and E, that should stack up vertically.

Select E and Alt/Command-Click tracker D and set it to Parallel to Z Axis image (or X axis if they should be horizontal).

Note : if you have set the preferences to "no middle mouse button" then you must hold ALT/Command and right-click to link, since ALT/Command-left would be interpreted as a pan.

 

©2024 Boris FX, Inc. — UNOFFICIAL — Converted from original PDF.