Thanks @moGRR for reaching out us. With regard to your question, as pointed out by @zipit, it's not possible to have a Python Generator to generate object which can be recognized as real spline by generators/deformers expecting a spline as input due to the Python Generator flags used in its registration. Beside the option mentioned by @zipit I also invite to have a look at this post where it's presented a generator outputting spline and accepting splines as input. Best, R

Hi sorry to jump on this topic so late, and I agree that if you could do what you want in a Python Scripting tag its preferred, the mains issue with xpresso is that its a whole system that assumes certain things and was really not designed to be embedded within a generator. So the issue about the AddNode, not working is because user data things, as an object xpresso node, is something dynamic (they will change according to the linked object) and I found no way except via the UI (by asking a UI Redraw or a whole scene execution) to refresh these data so the GvPort can be created. But since you are in a Generator you don't have access to the GUI since all GUI operation should be done in the Main thread see Threading Information. Cheers, Maxime.

@mp5gosu Ah brilliant. Thanks for that! And apologies for being such a noob at this.

Thanks again @PluginStudent for helping me so quickly. That was enough information to help me find the .MakeUserSpline function that allows me to do exactly what I'm after: MakeUserSpline('sin(x * PI)', 5) More info here for anyone looking. Cheers, Jamie

Oops - I forgot to have the following line: myDefObj[c4d.FIELDS] = myFieldList It all works perfectly now. Thanks again for your help @PluginStudent