@Simon Thommes (simonthommes) Should the output of this always be a color attribute? I just noticed that we have MixRGB for shaders, so it's specific to colors. Should it be the same here? Should the node name reflect that?

@Jacques Lucke (JacquesLucke) Hm, good question.
I feel like it should retain the type of the result attribute. For new attributes, I think, eventually it would be nice to have a dropdown when adding a new attribute within an input. But that's a larger scope todo on the UI side iirc.
For now it's fine to force color attributes (unclamped) for new attribute names, I would say.
This node should have the same viability for vector- and value- as for color-attributes, so I wouldn't change the name.

Alright, thanks. Will do as follows:

• If the result attribute exists already, its type is not changed.
• Otherwise, the new attribute will have the type color.

More options to control this behavior can be added later.

There is a working version of this node in the geometry-nodes-mix-attributes branch, if you want to test it.
It's a little bit annoying to use, because you have to prepare so many attributes currently.
On the bright side, this node can also be used for some vector math already.

Will rename to "Attribute Mix" and will add enums to select the input types (attribute/float/vector/color/...).

Will rename the inputs to just "A" and "B".