How do I get the Color value from an RGB node with Python?

Question

I'm a seasoned programmer, but fairly new to blender and 3D-modeling in general. So to get an understanding of different properties I want to write python scripts to create multiple renderings with different settings of various values.

In the example below I have figured out how to change the Volume Absorption Density, ex:

bpy.data.materials['MyMaterial'].node_tree.nodes['Volume Absorption'].inputs['Density'].default_value = 100

But not the RGB-node. It seems I cant even get the current values out of it. Some things I have tried:

bpy.data.materials['MyMaterial'].node_tree.nodes['RGB'].color
bpy.data.materials['MyMaterial'].node_tree.nodes['RGB'].color.r
bpy.data.materials['MyMaterial'].node_tree.nodes['RGB'].color.outputs['Color']

How do I get and set output values of the RGB-node in py python-script?

just fyi here's a script showing how you can build your nodes directly from python: https://blender.stackexchange.com/q/35436/5334 and here's another https://blender.stackexchange.com/q/34609/5334 — uhoh, Feb 18 '19 at 17:06

score 15 · Accepted Answer · answered Feb 18 '19 at 11:59

15

^{Welcome to Blender.SE, UlfR.}

Finding out a property in Blender is relatively easy. Make sure, you have python tooltips enabled (in the user preferences).

Then hover your mouse cursor over the property (in this case the color). A tooltip containing the python command will appear.

The property you seek seems to be outputs[0].default_value.

def_rgb = bpy.data.materials['MyMaterial'].node_tree.nodes['RGB'].outputs[0].default_value

It is a bpy_prop_array by default, so you may want to convert it to a list.

float_values = list(def_rgb)

answered Feb 18 '19 at 11:59

Leander

26,725
2
44
105

Miceterminator beat me to it by 3 minutes. I will leave this answer up, as it mentions the python tooltip and his doesn't you could accept his answer as the correct one however. – Leander Feb 18 '19 at 12:00
my problem was that bpy.data.materials[1].node_tree.nodes['RGB'].outputs[0].default_value = (1.0,1.0,0.5,1.0) works but bpy.data.materials[1].node_tree.nodes['RGB'].outputs[0].default_value produces nothing in the Python console. Converting it to list then displayed the hidden values. – rob Feb 18 '19 at 12:07
1

You can also access the individual values directly from the bpy_prop_array via their indices, such as def_rgb[0]. – Leander Feb 18 '19 at 22:21

miceterminator · Answer 2 · 2019-02-18T12:05:13.607

9

As you already found you way to the node tree, the "Copy data path" option is generally very helpful:

Right click on the field you want to access and use the "Copy data path" option.

bpy.data.materials['MyMaterial'].node_tree.nodes['RGB'].outputs[0].default_value

You can also look at the answers here and here

edited Feb 18 '19 at 12:05

answered Feb 18 '19 at 11:55

miceterminator

3,624
2
20
32

How do I get the Color value from an RGB node with Python?

2 Answers2

Linked