Bad Geometry Nodes with two objects and Dependency cycle error!

Support Modeling
1

I try to follow this video tutorial
From min 4:50 the object is not moving it.
Something happens and it works once ! … then I follow and do not work again
image
The terminal tells me :

Dependency cycle detected:
  OBBuffer/MODIFIER(GeometryNodes) depends on
  OBSim/GEOMETRY_EVAL() via 'Nodes Modifier'
  OBSim/MODIFIER(GeometryNodes) via 'modifier stack order'
  OBBuffer/GEOMETRY_EVAL() via 'Nodes Modifier'
  OBBuffer/MODIFIER(GeometryNodes) via 'modifier stack order'

Any idea?

2

@mythcat
first of all this is an outdated tutorial. before geometry nodes had a “loop zone” and “simulation zone” there was no straighforward way to make simulation since Geonode will never be able to read previous frames data which is a must in simulations. some smart people come up with the hack of using a buffer object and send data back and forward in between i think (never used this approach).

i can’t see your node tree the image is low res (if you can share more since it’s a tutorial maybe even the blend scene) but i want to draw your attention to the switch node that uses the frame number as trigger for that to work you need to start your timeline from frame 0 and not 1 (he did that at 3:57) without saying it (he assumed his followers knows about it)

if this doesn’t solve your issue please share more about your scene.

1 Like
3

…good pieces of information
I don’t know about “Geonode will never be able to read previous frames data which is a must in simulations”, I need to study more.

… about the screenshot … are the same nodes as in that video tutorial.

4

just to be sure i didn’t confuse you: Geometry nodes CAN NOW do that. i was talking about the TIME THAT TUTORIAL WAS MADE. and that’s why it was made that way.
so now you don’t need the second object at all (the buffer object) and have your simulation happen inside a “simulation zone”.

5

It is good to know these pieces of information … thank you!

1 Like