Adobe Director Basics

ADOBE DIRECTOR BASICS
3D: Controlling action
property pPointList -- list of n vector positions
property pRunningTotal -- sorted list of n-1 distances along path
property pTotalLength -- final value in pRunningTotal
on GetPosition(aRatio)
vDistance = pTotalLength * aRatio
vIndex = pRunningTotal.findPosNear(vDistance)
vLast = pPointList[vIndex - 1]
vNext = pPointList[vIndex]
vDirection = (vNext - vLast).getNormalized()
vComplete = pRunningTotal[vIndex - 1]
vRemaining = vDistance - vComplete
vPosition = vLast + vDirection * vRemaining
return vPosition
end GetPosition
Note the use of list.findPosNear() on a sorted list, to give the index of the next value in the sorted list, which is equal
to or greater than the requested value.
You can apply the position along the path to any kind of node, including cameras
Looking along the path
To get the node to turn to face along the path, you can simply ask for a position slightly further along the path, and use
node.pointAt() to make the node face in that direction.
Choose carefully how far ahead to look. Ideally, the position must be on the line segment one or two points further
along the path. If the point to look at is sometimes on the same segment, the node will alternate between rotating and
not rotating, and the effect will not be natural. If it's too far ahead, the node may tend to point in the wrong direction.
Last updated 8/26/2011
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