Geo nodes Animation: Instances animated one after another along a curve

What I would like to achieve using geometry nodes is something like a curved path consisting of stepping stones that sequentially appear out of thin air.

Instance steps Objects along a curve, oriented to the curve (aligned to the curve going up/down and sideways)
These objects have a position on the curve between 0 and 1
Have and empty or animatable parameter (start to end / 0-1) that corresponds to the curve
Have the objects react to this paramter
Objects start instanced in position A (eg raised) and with a transparent material
When parameter or empty is past their position on the curve animate the instanced object over a few frames into Position B and make them visible

So the steps are:

  • Instance and align points
  • For each point, get the position on the curve
  • Compare to currently set parameter
  • If greater, transform, not instantly but over a few frames (maybe using a falloff as a factor, unclear on this)
  • Bonus / Nice to have: cull instances outside of camera view (Not important right now)

Is this even feasible using geo neodes either 2.93 or 3.00 fields?

Things I am having the most problems with:

  • Get the parameter of a point along a curve (between 0 and 1, how far along is the point)
  • Separating the instanced points, accessing and moving them individually
  • Moving things into position over a few frames (could be done by a falloff?)
  • Should the instancing occur before the points are manipulated or afterwards?
  • Is there some workaround the inspect for example a float output? The viewer node only attaches to geometry socket types.
  • I am missing the “evaluate curve” node from the newer builds that seemed useful for my case, what happened to it?

I’ve also attached a video where I’ve fake the basic sans the invisibility part:

Thanks for any help, ideas or alternatives!

Try this as a starting point.

1 Like

Thanks, that helped me a couple of steps along!

What I am currently looking for is a way to get a float of how far along a given point is from the start of the curve. So the curve is parametrized zero to one and for a point on the curve I would need a float value of how far along the curve it is.

I am currently calculating distance from curve start point to point position but obviously that only works when the path is always going away from the start point.