Only way to Texture Paint imported image: Use Cycles node!

[justavisitor]

I've experimented with Texture Paint on imported images in the Octane plugin and, as far as I can see, there's only one way to make it work:

Use a Cycles Image Tex node.

This seems to be an exception from the release notes that the plugin knows nothing about Blender specific materials and textures (or any Blender nodes).

So in the attached .blend, you can only paint on "redhairPreview.JPG" because of the unconnected Cycles Image Texture node (please see the image below).

If you delete the Cycles node, you can still paint on the .jpg, but you will lose your work when you save the file - also if you Save All Images - because the Cycles node is gone.

Here's how to do it in a simple project:

1) Start new project
2) Add Octane material to the default cube
3) UV-unwrap the cube
4) Go into Texture Paint mode
5) You get the Missing Data warning. Click Add Paint Slot. This creates the necessary Cycles Image Texture node
6) In the UV-Editor/Image, click Open and open an image, i.e. X.jpg
7) Open X.jpg in the Cycles Image Texture
8) Add an Octane Image Tex and connect it to your Octane Material node
9) Select X.jpg in the Octane Image Tex
10) Make sure that X.jpg is selected in Properties Window/Textures/Node
11) You can now paint on the cube, and the image is updated in the UV-editor - however, it does NOT render yet.
12) In the UV-editor/Image, click Pack Image. You'll be asked to pack as .png. Do that.
13) When you paint on the object, it will now render as expected.
14) Remember to go into UV-editor/Image and Save All Images and then save the project before you close.

[Garquitectos]

Very interesting! Many thanks for sharing. If you know something similar to bake textures with Octane...

[justavisitor]

Thank you. I'm sorry, but I don't know anything about baking.

[justavisitor]

For those of you who want to use Texture Paint in Octane, I'd just like to add that to steps above that in some cases you'll get an error message when you click SAVE ALL IMAGES.

In that case, you should click SAVE IMAGE.