While testing a change to an add-on that automatically creates node groups I noticed that the links in the group in the Geometry Node Editor window were dashed instead of solid. It seems to be related to the input group - so that the links proliferate through the tree - as they revert back to being continuous when not linked to the Node Group Input node as demonstrated in this animated image :

animated showing dashed lines

Iinitially thought I'd managed to manually create the node group without having the same problem but on re-trying it does seem to occur with manually created groups (so perhaps it's not my code after all!). Presumably, this behaviour is intentional and indicating something.

The nodes still seem to work as expected and produce the same output. What do these dashed links indicate? I haven't spotted the same happening in the Shader or Compositor node editor windows so maybe this is Geometry Node related only.

Note that this was on Blender version 3.00 (I know - it's an unfinished development release... perhaps this is just a new feature...?)


This is something new for 3.00 as of change T91563 and the Release Notes report that

Dashed lines are used to represent the flow of functions while data-flow node links look the same as before

The feature is meant to support the field rewrite of Geometry Nodes.

This has been a very controversial choice and there is massive user feedback on devtalk, but it is unlikely that this will change.

  • $\begingroup$ Thanks @Marty - that’s really helpful info. I can see why highlighting this might be useful and have noticed that if you hover over the ‘data’ sockets you get a display of the value at that point, which is quite helpful when you know about it. I do think the choice of dashed line is a bad one though - it gives the wrong impression as I thing the ‘function’ dataflow should be highlighted as somehow stronger since there is more content, rather than weaker as it seems with dashed lines. Different colours would have been sufficient (blue/green, blue/cyan, green/yellow or something like that). $\endgroup$ Oct 7 '21 at 22:15
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    $\begingroup$ The most common complaint on Devtalk is precisely what you said, so there's some hope that this will change in future. Of course, the problem with using colors is that they introduce their own set of readability issues, especially for the color blind. (The principle cause of problems is solutions.) $\endgroup$ Oct 7 '21 at 22:17

It seems to be an early attempt to distinguish function flow from data flow.

Quoting the relevant developer task:

The "data flow" is evaluated at every single node. A user can inspect the output sockets of those nodes and have a glimpse at their values.

The "function flow" (nodes) however is only evaluated in the geometry nodes. The noodles are not transporting data in the same sense of the "data flow". All that can be inspected are the attributes the functions depend on.

The project seems to be abandoned now, or at least stagnant

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    $\begingroup$ Thanks @Duarte - that’s really helpful info. IMO the dashed line is the wrong and confusing choice for this but I can see why it’s useful to distinguish them - and do like the new hover-over display of the data at a socket. Different colours would probably be clearer, less confusing and easier to implement. Hope you don’t mind me marking Marty’s answer as accepted - the two are very equal and so I chose based on who’d gain the most from the reputation points! :-) $\endgroup$ Oct 7 '21 at 22:21
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    $\begingroup$ No problem, seems fair. From my superficial understanding it was quite a controversial change it might not be kept in the long run $\endgroup$ Oct 7 '21 at 23:52
  • $\begingroup$ I noticed in the new 3.00 build the link lines take on the colour of the socket throughout all the node editors. Must say I like the updated node editors. $\endgroup$ Dec 3 '21 at 23:55
  • $\begingroup$ Thanks for the reminder almost forgot to download it, gotta give it a try, haven't really played with 3.0 yet $\endgroup$ Dec 4 '21 at 0:03

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