I have a wave modifier on on object which has a couple of array modifier. i object , then an array to make it 10 , then an array to make total 100(multiply) .Then these 100 peices (one single) have a wave modifier starting a empty.

The node map is enter image description here

As you can see there is some strange color at places where there is no emission shader. Why is it soand how to solve it.

  • $\begingroup$ What is your World background set to? $\endgroup$ Oct 9, 2020 at 6:41
  • $\begingroup$ black colour is my background $\endgroup$ Oct 9, 2020 at 7:11
  • $\begingroup$ What is your intention in adding the (World Space) Normal X and Y components? What end result are you looking for? $\endgroup$
    – Robin Betts
    Oct 9, 2020 at 7:20
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    $\begingroup$ Are you using any kind of denoising? Does the blue change colour if you change the colour of the emission? Are you using GPU or CPU for rendering? Does the problem go away if you enable 'Clamp' on the Add node? $\endgroup$ Oct 9, 2020 at 8:03
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    $\begingroup$ @RichSedman yes the problem gets solved by enabling clamp , write that in the awnsere and also explain how and why does that solve the problem? $\endgroup$ Oct 9, 2020 at 9:49

1 Answer 1


The problem appears to be due to negative values being used in the Mix factor resulting in artifacts where the 'negative' of the orange colour is becoming evident.

Each channel from the Normal is in the range -1.0 through to +1.0 and so the 'add' can result in negative values. Normally a 'mix' factor will automatically clamp the values at 0.0 and 1.0 but in this case that doesn't seem to be happening. By enabling 'Clamp' you are limiting the output of the Add maths node to strictly the 0.0 to 1.0 range so that the mix is behaving consistently.


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