I've been trying to get this to work for a few days, but I can't seem to find out how. I want to have an object with two colours (materials) reflect light seamlessly. These objects are generated procedurally, so manually integrating these colour changes in the uv map is not a solution (there are about 4000 repetitions).

Blender does the following: entire step reflects light Expected normal behaviour: entire step reflects light

Reflections and shadows break at the edges Unwanted behaviour: the light and shadow breaks at the edges

What it looks like without added edges What it looks like without added edges

What it looks like with the added edges What it looks like with the added edges

How can I force the light to be reflected normally across the edges?

Edit: PGmath suggested recalculating normals and auto smoothing. Recalculating normals had no effect, auto smoothing has the following effect: with auto smoothing The material looks completely matte now

I have tried using ALT+N > Merge with auto-smooth, which has a better result, but still not as desired:

normals merged

  • $\begingroup$ It looks like you have some smooth shading artifacts, try turning on auto smooth. Its hard to tell but you may also have some inverted normals on you model so I would also try recalculating the normals (Ctrl+N). $\endgroup$
    – PGmath
    Feb 9 at 15:08
  • $\begingroup$ Thanks for you comment PGmath, I have updated the post with new images $\endgroup$
    – June
    Feb 9 at 15:29
  • $\begingroup$ have you tried using generated projection for the image? $\endgroup$
    – J Block
    Feb 9 at 15:59
  • $\begingroup$ My guess is that the result is "correct" once you applied auto smooth. Smooth shading bends the normals on flat faces to make them appear curved, so now that the faces are correctly reflecting glossy rays as a flat surface, they look matte because there isn't enough in the environment to make nice looking glossy reflections. If you plan to fill in the rest of the scene and make this indoors I suggest doing that first, otherwise you can use an HDR panoramic environment texture to make some nice looking reflections. $\endgroup$
    – PGmath
    Feb 9 at 16:08
  • $\begingroup$ I think you may be right, PGmath, when I place the first stairs (that I thought looked right) in an HDR environment, it has really odd reflections, the one with your adjustments has proper reflections. It still has some odd stuff going on around the corners, but maybe I can live with that. $\endgroup$
    – June
    Feb 9 at 17:23

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