Solving Issues | Boris FX

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‌Solving Issues

If you encounter the message "Can't find suitable initial frames", it means that there is limited perspective in the shot, or that the Constrain button is on, but the constrained trackers are not simultaneously valid. Turn on the checkboxes next to Begin and End frames on the Solver panel, and select two frames with many trackers in common, where the camera or object rotates around 30 degrees between the two

frames. You will see the number of trackers in common between the two frames, you want this to be as high as possible. Make sure the two frames have a large perspective change as well: a large number of trackers will do no good if they do not also exhibit a perspective change. Also, it will be a good idea to turn on the "Slow but sure" checkbox.

You may encounter "size constraint hasn't been set up" under various circumstances. If the solving process stops immediately, probably you have no trackers set up for the camera or object cited. Note that if you are doing a moving object shot, you need to set the camera’s solving mode to Disabled if you are not tracking it also, or you will get this message.

When you are tracking both a moving camera and a moving object, you need to have a size constraint for the camera (one way or another), and a size constraint for the object (one way or another). So you need TWO size constraints. It isn't immediately obvious to many people why TWO size constraints are needed. This is the related to a well-known optical illusion, relied on in shooting movies such as "Honey, I Shrunk the Kids". Basically, you can't tell the difference between a little thing moving around a little, up close, and a big thing moving around a lot, farther away. You need the two size constraints to set the relative proportions of the foreground (object) and background (camera).

The related message “Had to add a size constraint, none provided” is informational, and does not indicate a problem.

If you have SynthEyes scenes with multiple cameras linked to one another, you should keep the solver panel’s Constrain button turned on to maintain proper common alignment.