How to instance with Bifrost and add animation delay(random)

[takaharu_tobe]

Hi,

I instantiated the animated model by bifrost and placed it.

I wanted to stagger the animations of the instantiated models individually, but I didn't know how to do it.
How do you shift the animation?

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MAYA : 2020.4
Bifrost : 2.2.00

[jason-t-brown]

I think the best way to achieve this is by bringing your animation in as an alembic file and randomly offsetting the input time in the graph.

[takaharu_tobe]

Thanks!

I tried Alembic, but I don't know where to connect randam or offset.

What should I do now?
I'm sorry for bothering you.

[Roland.Reyer · Accepted solution]

Depending on your animated objects you could also create "Animated Snapshots" and then use the create_instances node to play through these objects on a per point bases.

The offset per instance point could be a point property like particle age.

In this example I'm using a field (the wireframe sphere) to set a value for the points (flowers) and that chooses 1 out of 40 anim snapshots.

[jason-t-brown · Accepted solution]

Based on @Roland.Reyer's answer up there, my solution would be this:  Make a for-each loop.  The max iterations should be set to the number of different, random offsets you wish to instance, so if you want 20 different animations, set it to 20.

Inside that for-each loop, add a time node, add a random number to it that changes (current_iteration into seed), then a modulo for looping (modulo returns the remainder of a division, so if you have 40 frames and a modulo set to 40, on frame 41 it will return 1, frame 42 returns 2, etc).  Plug the modulo into the frame input of your alembic read node and connect that to the output f the loop.

This will generate the number of instance geometries you want, with random animations.

[jason-t-brown]

If you don't want it to be random, convert the current_index to a float and add whatever delay you need to it then add that to the frame 🙂

[takaharu_tobe]

@Roland.Reyer
@jason-t-brown

Thank you for your kindness!

Bifrost is complicated and I don't know what to do by myself.
I will try various things based on what I was taught this time.

[jason-t-brown]

Zero problems, feel free to reach out anytime!

[kongyingjie]

Noticed random_value node is a bit special. The output value increases as "max" increases, not absolutely random.

Look in the following attachment screen shot.

[Roland.Reyer]

@kongyingjie 

The random number will always be the same until you change the *seed*.
min and max are only offset and scaling. 

If you plug the frame number into seed then you’ll get a new random number every frame.