Animating randomized visibility over a cluster of geo objects


Greetings all,

I’m posting this question on more than one thread as I have a situation that’s not quite a newby-question, though hoping to get some advice or guidance on something specific that I imagine may require an Expresso setup, though perhaps it’s possible to achieve by other means.

What I’d like to do is animate the visibility (alpha value, but not the Transparency property) of a group of 50 or so discreet geometry objects so that they go from fully invisible to fully visible one by one.

  • Each object should fade from 0 to 100% opacity over the course of about 6 frames, though randomizing slightly this per object would be optimal (some could take 4 frames, some could take 8 frames, etc.)
  • I’d want to make the fade-on time of each object based on its y-position value, so that objects at the bottom of the pile appear first and objects at the top appear last
  • The total animation will need to be about 4 seconds, so at 0:00, none of the objects are visible, but at 4:00 all objects are visible
  • The objects are already placed and I don’t have much flexibility to change thisThe 50 objects don’t all have the same material.
  • There are already 3 discreet materials applied across the 50 objects (but none of the objects has more than a single material applied to it.)

The brut-force way to do this would obviously be to set up more materials than I already have, apply them to the appropriate objects and manually animate the Alpha property of each material. Kinda trying to avoid this, since object count is fairly high.

I imagine this could be approached something like the following ( though don’t have much experience with Expresso or other scripting to know if this is a wise approach).Get the points of an Array object or MoGraph Cloner to conform to coordinates of the pre-placed set of geo objectsUse some animatable property of the Cloner to drive the visibility or alpha property of each object.
Any advice here would be massively appreciated!



This is just the sort of task that the Mograph toolset was made for.

Take a look at this file:

I mocked it up with a cloner object, but you can easily take your objects, place them in a Fracture object, and get the same result.

Essentially, you use a Plain effector to change the ‘color’ attribute of each mograph object, and then place a Mograph Color shader into the alpha texture slot in each of your materials. The random effector is used to change the “weight” of the effect so that they all aren’t transitioning at the same time.


Many thanks Luke :bowdown:

I will definitely give this a try with the Fracture setup.


Works like a charm - thank you again!!!



Wonderful! Glad I could help you out.