Double-sided materials ...

  • Poser Ambassadors

    ... can be rendered on single-sided geometry using Cycles nodes and Superfly. Here's a simple prop in Preview with Force Show Backfacing Polys selected in its Properties-

    0_1463162679861_force show.JPG

    Just to make it absolutely clear, if I select Force Hide Backfacing Polys, the Preview looks like this -

    0_1463162837704_force hide.JPG

    But using Superfly to render it I can do this -

    0_1463162911313_sf render.jpg

    And this is the shader -


    First I added the CyclesSurface (right-click, New node -> Root) and ticked it to be used when rendering with Superfly. I've then added two DiffuseBsdf nodes (New node -> Cycles -> Shader) and given each a distinctive colour. These are connected to a MixClosure node from the same shader submenu. Finally I've added the bit that makes this work - a Geometry node (Cycles -> Input) with Backfacing connected to Fac on the MixClosure. This tells Superfly to render whatever is plugged into Closure1 on the front face of the polygons and whatever is plugged into Closure2 on the back face.

    Those two Diffuse nodes would of course be replaced by two complete materials; I've been playing around with leaves in particular but I imagine this may be of more interest to anyone using dynamic cloth in their renders ...

  • That is actually pretty cool!

  • That is awesome. Now we can have clothing that looks like is has a lining without the extra geometry.

  • Yes, that's definitely something I'll have to try. Thanks for posting this. :smile:

  • Poser Ambassadors

    I tried this with textures instead of color, but were unable to get a result. All surfaces render black when i attached a texture. Have you been able to do that?

  • try plugging the image map node into the diffuse nodes color spot.

  • Variants of nodetrees

    0_1463649641765_SF basic 2sided.png


    And some experimentation from couple of weeks ago

    0_1463650063471_Carnations 2 tm.png

    0_1463650239826_Fire from snow.png

  • @phdubrov I tried a similar setup to that first screenshot, with two textures, both in black and white but different designs, and it rendered all white. As mentioned, not all textures work with that method.

    I'm going to try the method in that second screenshot and see if that does the trick.

    BTW, that second render with the flowers looks great with the white backs. :smile:

  • @Miss-B thanks.
    Can you post an example of not working nodetree?
    I had one side black in experimentation with variants of glossy mixes, but never pure white and never had troubles with diffuse mixes.

  • I can, but it's going to have to wait until this evening, as I'm in the middle of a SuperFly render I want to see to the end.

    I can say I had no problem getting it to render with just the two DiffuseBSD color nodes, but once I plugged textures into the Color nodes, I still only got colors. I'll get back to you with a couple of screenshots later, but I checked my set up node-for-node with the one you posted, and it's not working.

    Later . . .

  • OK, I'm back. Here are two screenshots. The first was my initial try with just the color nodes set to two different colors, which works fine.

    alt text

    The second render is my try with image maps plugged into the afore-mentioned color nodes, which I can't seem to get to work.

    alt text

  • @Miss-B is object UV-mapped? (Just realize all objects I worked were.)
    Can you try with full Cycles texture setup?

  • Well DUUUUUH! I hadn't thought about UV mapping. No, all I did was create a simple cylinder in Blender, and exported the OBJ. Let me try that and see if I can get it to work.

    Geeze, I've been working in Blender for close to 10 years, you'd think by now I would've done that automatically. :headdesk:

  • SUCCESS!!! UV Mapping did the trick, but I'll be trying out the other method you posted above to see how that goes.

    alt text

  • OK, I tried out the full Cycles method and got it to work . . . soft of. It turns out, the only way I can get it to cover the whole front face was to plug the ImageTexture into the TextureCoordinate's Window node. The others either look like warped versions of my test texture, or the texture only covered the bottom half, with the top and some of the bottom solid black. That's why I started experimenting with the other TextureCoordinate nodes to see if I could cover it all.

    The problem now is, it's twice the size it should be, so how do I get it to display as I originally had it? You can see the difference, as the backfacing texture is still the original Image_Map setup.

    alt text