This video is part of a set of 5 others that details :
- introduction for the tools
- modeling (1),
- modeling (2)
- UV map creation and
- texturing with UcuPaint
It was only yesterday that I really started to "
play" with Ucupaint, this morning I started again quietly and I understood how to select objects or parts to insert them into a "
Layer Group".
The method is as follows:
- first in UcuPaint you click on the
Layer Group
- In 3D Viewport, in Edit mode, you click on a polygon that turns into an over-brightness,
- then we
press L to select the other polygons of the desired part,
- By keeping the
SHIFT key pressed,
we keep these selections,
- we move and click on another polygon from another part,
- there,
release the SHIFT key (important) and
press L to select the second part then
press SHIFT again to store both selections
- and so on.
In the end, to "move theses selections into the Layer Group, we
go back to Texture Paint mode, we check as in the video that on the T menu we have
selected the
"Fill" tool, and finally we
click on one of the selected parts : to see if it worked, you
need to switch back to Objects mode.
Here the result of 1 hour of work for this morning : oil tank is colored with a grunge layer, attachs are in yellow with some rust, tube are with same "color" than the tank, bolts are in blue and I have begin to texture my life boat package ...
PS: On this screenshot I have use a HDRi image en background to highlight my objects and send more light on it.
In the "Preview Mode", the choice of different colors are not definitive and you could select a layer and move your slider to obtain a better result at any time.
After some hours of works and learning with this video, I am happy of the result ... in Blender: I even managed quite easily to create an ExtraNormale to add rivets on the yellow fastenings of the oil tank.
Now, the final step which consist in backing all this stuff in a set of PBR textures. If it is OK it will fun, if not ...

...
The bake take less than 1 mn and the result seems OK in a first stage, but no metallic texture appear in the result
By following the video point by point to build my textures, no metallic-type texture or roughness is implicitly configured, but despite everything, the final result does indeed include a rugosity due to the "grunge_01.png" file introduced for the oil tank, but no metallic texture is present.
While watching the video again, the author strongly advises to read a blog post from another creator:
https://passivestar.xyz/posts/texturing-in-blender-with-ucupaint ...
After consulting this article, which proposes to texture a gas bottle, we realize that the Jeep video did not address a very important point: the possibility of adding metal and roughtness channels on a new layers:
this can be done by changing Layer Color to Custom Value on them.

With this new option, you can create others channels on your layers and obtain that you desire. This will be my practical work for this afternoon, after a good lunch.
The better to understand this is
to read with attention this article (24 pages ! ) which is a very good complement to this video.
Good reading and learning of Ucupaint