how to retrieve the output value in python/driver of a geometry nodes attribut?

Question

I have a GN node tree with an output value as a float.

Blender tells me the path to it, which is great. And i got...if i execute it...an "x" ...umpf.

Hoped for a value. How do i get the value?

Linkage: Accessing Geometry Nodes mesh data from Python, Find object instances with python, Blender 4: blf module: How to draw text in the center?, Blender 3.6: Convert curve to mesh with specified resolution via API, and using a driver: Control shape keys with drivers to the speed of rotation — Markus von Broady, Feb 29 '24 at 10:47
@MarkusvonBroady: but you are aware of the fact, that the question was asked 2022 and you add links from 2023? Makes less sense for me.... — Chris, Feb 29 '24 at 12:01
why? It seems to you posting a link is some kind of a reprimand "you should have known about this because we already wrote about it before", whereas I treat them as signposts: we're here, look at the directions to ontological neighbors. — Markus von Broady, Feb 29 '24 at 14:41

score 8 · Accepted Answer · answered Jan 12 '22 at 13:44

8

You need to refer to the object attributes, so if the attribute is a vector you can do:

obj = bpy.context.object.evaluated_get(bpy.context.evaluated_depsgraph_get()).data
obj.attributes[0].data[0].vector

You might need to adjust the indexes for your attributes.

answered Jan 12 '22 at 13:44

Hezi Shahmoon

2

Hi! Is there a systematic way of chasing this kind of information down, or is it just something you have to know?, and is there a way of guaranteeing the index? e.g finding index for name? – Robin Betts Jan 12 '22 at 13:58
2

Hi. This is somewhat explained here: https://b3d.interplanety.org/en/accessing-custom-attributes-created-in-geometry-nodes/ – Hezi Shahmoon Jan 12 '22 at 16:03
1

Thank you! Good source :) – Robin Betts Jan 12 '22 at 16:13

1 Answers1