Subsurface material assignment and other observations


(Wim Dekeyser) #1

I don’t want to disturb the thread above that was started just now. In testing, I got pretty confused about how this is supposed to work…

  • Make a box
  • In the Rendering panel, press the 00 Reset To Defaults button to make sure that everything is as factory-default.
  • In the Materials panel [which is completely empty at this point], make a new material (e.g. green paint).
  • Sub-select one face of the box using Ctrl Shift LMB. Drag the material to the face.

I tried both dragging with Ctrl Shift and without keyboard keys. Sometimes I get a message saying that I can only drop 1 item at a time; sometimes this message doesn’t come up.
image
At any rate, I don’t know why I would be dropping 2 or more items?

Also, why does the mouse pointer read Copy? I am not making a copy of the material?

Going on then…

  • With one face selected, go to the Properties panel and click on the materials tab. Click on Use Layer Material to override this.

    Why isn’t the “Default material” listed in the Materials panel?
  • Click on the green paint material. The one face is now green.
  • As soon as you do this, a (unnamed) material is added to the Materials panel. Why is this one added? It’s not the “Default material” because now the material tab on the properties panel both has that “Default material” and the (unnamed).

I then proceeded to assign two more plastic materials to two of the other faces of the box. After that - somehow [that I cannot reproduce now], I changed the (unnamed) material to be glass. This made the three plastic materials turn into glass as well.

File in that state:
paint to glass 2.3dm (291.3 KB)

I tried to do this in a new file but didn’t find out anymore how to get the 3 plastic materials to change to glass at once.

When I then started undoing things to try to reproduce, I found that even when a plastic-material-turned-glass again became a plastic material, it still rendered transparent.

In Windows Explorer, this file looks like this (see the thumbnail):

But when I open that file again, it is back to normal:
image


(Pascal Golay) #2

Hi Wim - yeah, this has been a bone of contention here… and it (Default material) is there in 6.2.

Also, for the rest of your observations … “yep”. I’ll add some bugs.

It appears that the rest of the box gets the new un-named material. Oi. I don’t know, but I have a feeling this is necessary for sub-object assignment… I’ll ask. @andy - is that correct?

Another bug here is that if you do this more than once, multiple materials named unnamed show up - even if the behavior is somehow correct, these unnamed materials should have incremented unnamed-ness.
https://mcneel.myjetbrains.com/youtrack/issue/RH-43978

Also this - https://mcneel.myjetbrains.com/youtrack/issue/RH-43980

And furthermore… if you assign sub-object materials to all faces of a box, and then delete that ‘unnamed’ one, all of the faces lose their assignments and are returned to the default material. Also true if there’s an overall material explicitly assigned, and then all faces over ridden per face. The per face assignments are lost if the top level object material is deleted. I have a feeling we are looking behind the curtain here more than is healthy - this may all be necessary at some level to allow sub-object materials to work but the machinery needs to be hidden or handled a little more effectively so users do not get into trouble.

thanks,

-Pascal