Drive color via custom property

Question

I have an model with an armature. On several bones are custom properties which are used in drivers.
At the end, the model and the armature should be linked in another scene and the custom properties are used to control certain functions of the model.

My problem now is that I want to control a color of an material node by means of a custom property. For that I added the hex value of the color to the property to use this value in a corresponding driver which should set the color of the material node. But the variables in the driver only accept numeric values and hex is a string. Is there any other way to control a color in a linked object?

Blender 2.75, on Windows

Answer 1

With current blender versions, you can create multi-dimensional custom property fields. These will look this:

You create them by setting the value on your custom property to this format:

[0.2, 0.4, 0.3]

Be sure to set your color value to the correct type, the default is "linear", for RGB values "gamma-corrected" is usually what you would want.

You can then draw this property anywhere in the blender UI, if you wish. This is a short breakdown on the naming conventions

If you want to use this to drive a material color on an object, so the color picker actually influences the color of a part of a model, you should set up a RGB-node in the Shader-Node-Tree (the Shader Editor).

Open the input field for the color and then add a driver to each color channel.

To access the channels as driver input variables, use the following pattern:

["NameOfCustomProperty"][NumberOfChannel]

or in an example

["color_ball"][0]

this would give the red channel.

["color_ball"][1]

this would give the green channel.

["color_ball"][2]

this would give the blue channel.

Answer 2

As you have found the Driver values that you can setup to use in your python expressions are limited to float values. Instead of setting a hex value you can setup three float values, one for red, one for blue and one for green.

Select the relevant bone you want to hold your colour settings and create three properties, for simplicity I will name then red, green and blue.

Add a driver to the colour swatch in your material (this can be used for either BI or cycles materials) and setup the driver to to get a single property from the rig and enter the path as pose.bones["ear.l"]["red"] - adjusting the bone name to suit. Repeat for each colour channel.

To make it more user friendly you can also setup a panel to display these properties at the side of the 3dview.

Here is an example file setup.