I've modeled an object in geonodes and have one issue with its shading. Object has 2 materials: one for hexagonal faces and another one for sides. I don't like the shininess of the faces and want to somehow reduce their brightness, but no matter what I change in the material setting they remain shining. I guess the lighting is just too much, but if I reduce then the sides of the sticks will be too dark. Is there some workaround?

Here's sample blend file: https://1drv.ms/u/s!AgCDDnfGXq0l3DUmW_kpBhXpTOld?e=pjLO14

my material preview

  • 2
    $\begingroup$ Couldyou share a minimal version which has the problem on pasteall.org/blend ? $\endgroup$
    – Robin Betts
    May 17, 2022 at 16:25
  • $\begingroup$ Make the sticks a lighter color, or make the other material in question a really dark color. It sounds like basic physics to me. $\endgroup$
    – TheLabCat
    May 17, 2022 at 17:51
  • $\begingroup$ @TheLabCat I've added sample blend file. It looks like hexagonal caps are overexposed, but if I lower the light power, then other parts will be underexposed. Also no matter what color, roughness, etc I set for the caps, they always look just white. Making 2 renders with different light settings and then merging them in photoshop sounds like an overkill. $\endgroup$ May 18, 2022 at 11:44
  • $\begingroup$ Will check out when I get a chance if not solved already. For future reference, use blend-exchange.com when possible, or pasteall.org/blend for larger files $\endgroup$
    – TheLabCat
    May 18, 2022 at 12:20
  • 2
    $\begingroup$ Something is weird with your setup. I tested the blend file to see if I could replace the shader with one that would ignore the physical lighting setup, and even when using the Holdout shader (which should be purely black or transparent, not even regarding lighting at all) those faces are still pure white. $\endgroup$
    – Ben
    May 18, 2022 at 15:33

1 Answer 1


It's not the material that's the issue here, it's that geometry nodes is merging the geometry of the mesh with another copy of the same geometry that has the default material (which is bright and fairly shiny) and that's what's causing the white reflection.

geometry nodes and result

This shows what's happening - the above image shows the result when replacing the material (actually, all the materials) with a shadeless green, it ignores light and only displays green, and yet the white faces STILL show up with this node tree - because when the extruded mesh geometry was passed to two Set Material nodes, it was duplicated, and then when those two sets of geometry are merged, they keep the default material in whatever location was not selected. By displaying just one of the set material nodes (the Sides in this case) we can see that the faces are still set to the default material. I'm not actually certain why this only causes problems on the extruded faces (perhaps some sort of z-ordering issue), but that is the problem here.

It can be resolved by using both set material nodes in series, and not performing a join material node, like so: fixed

This sets the material in both places, but doesn't duplicate any geometry.

  • $\begingroup$ thx a lot, I wasn't sure how to connect them $\endgroup$ May 18, 2022 at 16:35

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