Node Editor

[XBagon]

I wondered how feasible a node editor built on top of egui would be. I'm guessing it would need some internal work, to be able to draw connections and the connection points on windows?

[emilk]

It should be fairly feasible, either by doing manual drawing and widget layout, or by using Windows as you nodes. I have experimented with the latter in the branch demo-node-graph: https://github.com/emilk/egui/blob/demo-node-graph/egui_demo_lib/src/apps/node_graph.rs but haven't had time to finish that up (lacks the adding and removing of edges).

[torsteingrindvik]

Hi, I found this thread randomly while checking if egui supports drawing graphs.
Seems it might be on its way.

Just chiming in to show interest.

Thanks for the great lib!

[samcarey]

I'm also interested in such a feature. It would be nice if the graph could be zoomable with the mouse wheel, but I'm not sure how difficult that would be.

[francesco-cattoglio]

I am super interested in something like this, because right now my software relies on imgui to have a functioning node graph editor and I am trying to make my project rust-only.
I would love to get involved in developing such a node editor in egui (having stuff like a scrollable area, zoomable graph, and such). Would you like to invest some time helping me getting on board for this?

[emilk]

Has anyone tried https://github.com/haighcam/egui_nodes ?

[francesco-cattoglio]

I did, and there is one major point that I would like to address: there are many situations in which implementing correctly a node graph is as much work as implementing the egui window system from scratch: as an example, right now if have the node "1" containing a text edit widget and put a node "2" in the front, you can click through node "2" which is in front node and start writing in the text field, even node "1" is completely hidden. Similarly, hovering and similar interactions also require you to re-write lots of code to mimic the behaviour of windows. I am using imnodes myself right now and I appreciate the effort of somebody trying to port it over to egui, but I feel like a different approach might yield a better result.

[emilk]

Yeah, being able to reuse egui::Window or egui::Area would be great (like I started doing in https://github.com/emilk/egui/blob/demo-node-graph/egui_demo_lib/src/apps/node_graph.rs)

[francesco-cattoglio]

I started experimenting and found out that one can allow windows to move "out of frame bounds" by setting drag_bounds(Rect::EVERYTHING) at window build time, which is a very much needed feature. The only drawback is that in my little experiment it could go above the side panels, but I am pretty sure it is something that can be fixed rather easily.

I think this could be a good way to approach the implementation. I will spend some time exploring and then report back when I have a little more knowledge about the whole thing.

[ricardoalcantara]

Let me revive this thread! I checked this repo https://github.com/haighcam/egui_nodes and it's broken, last update uses egui 0.16. I liked your implementation https://github.com/emilk/egui/blob/demo-node-graph/egui_demo_lib/src/apps/node_graph.rs, it was the simplest and the one I could easily understand, and also had tried something like that before too, just a few things I would like to point, the Windows cannot go out side the canvas and it limits the size of the graph, with that it would be nice to have a way to scroll it. Do you think it's feasible to achieve that?

[wjbuys]

Check out https://github.com/setzer22/egui_node_graph

[milewski]

It's dead now :(

[theoparis]

I forked egui_nodes by haighcam here if you are interested: https://github.com/tinted-software/egui_nodes

[trevyn]

Also available and maintained: https://github.com/trevyn/egui_node_graph2