I'm trying to make a little scene with a light turning off and on randomly, I tried adding a keyframe to the light power and applying a noise modifier. However the result is too "soft", I mean the light just get a little dimmer or brighter. I'd like to know if there was a way to make the light just turning off and on randomly without having to manually add keyframe through the whole timeline.


You need to have the noise modifier set up, as you already do. now add a limits modifiers. there are four checkboxes. Check Maximum Y, and Minimum Y, and set the maximum value to the maximum strength you want for your light, and set the minimum value to the minimum strength you want for you light. The animation will still look to smooth, so crank the strength value of your noise modifier until you get a curve that looks more binary.

I hope this helps :)

  • 2
    $\begingroup$ wops, sorry, I saw your answer too late. If it's ok I'll leave mine up to keep the gif $\endgroup$ – Tareyes Oct 19 '19 at 22:52
  • $\begingroup$ That's fine. :) The gif is really helpful. $\endgroup$ – Millard Oct 19 '19 at 23:27
  • $\begingroup$ Thanks to both of you, it works great ! I'm fairly new to Blender so I think i'll stick to the simple modifiers and leave nodes for later because it kinda looks terrifying right now haha $\endgroup$ – Alexis Trilleaud Oct 19 '19 at 23:29
  • $\begingroup$ yeah, nodes are kind of intimidating at first. :) For simple materials, you can just add a principled shader node, and adjust the roughness, color, and metallic settings. (metallic should be either 0, or 1. if you are making something metal, it should be one. if not, it should be 0. $\endgroup$ – Millard Oct 19 '19 at 23:35
  • $\begingroup$ Yes, nodes are powerful but quite intimidating. If you plan on using Blender a lot you need to learn how to use them (they are not that difficult, but you need to spend some time on them), but for now the modifiers are a very good option, and the fact you can see the fcurve shape is a very good thing too $\endgroup$ – Tareyes Oct 20 '19 at 13:40

You can use the Noise Modifier: just increase a lot the strenght of the noise and the add a Limits Modifier, to clip the values between 0 and your maximum desired value

enter image description here

This is the quick and easy way. If you want more control you could use nodes (I am thinking of a noise modifier applied to the value of the strenght of the an Emission shader, using Greater Than and Less Than nodes), but you would need to use a mesh instead of a light object


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