Xpresso messes up existing keyframes

[Brian Jones]

when you plug a value into the xpresso port of a parameter in your light (or any parameter) you should notice an arrow in the keyframe dot – it indicates there is xpresso driving the value. If nothing else is changed the xpresso gets listened to not the keyframes.
But you can add the light’s intensity (I assume you are using intensity) in the xpresso by using the intensity Outport from the light node and add the xpresso value (I assume Noise) to that. Then plug back into the light’s Inport – that way the keyframe’s value and xpresso can be added together.
Here’s an example with that – it also has the noise being multiplied by the light’s up-ramping intensity so the light starts off and then flickers as it ramps up, then some code to add the noise calculation if the light’s intensity is less than 100% (1) or add nothing after that so the light stabilizes at 100%.

9723_lightflickersasitturnson.c4d.zip

I left two nodes from my first test as an example there is usually more than one way (is the animation at less than an 30 frames? – where the keyframed values are for this test but I figured your lights will be turning on somewhere down the timeline and maybe not altogether so why not use the light’s own intensity to control whether the flicker occurs or not)

[Gregory Musch]

Thanks Brian! I’m checking out the scene file now! This was very informative. Like I mentioned, I’m kinda new at using Xpresso, but glad to have others help me figure this out ha. And yes, the animation is longer than 30 frames. I have several lights coming on a different times. I’ll fiddle with this and I’m sure I have enough to go off now to figure it out. Thanks so much for the advice!!!