Material Panner with parameter value goes too fast when changing
Update 1: Video with more information of problem
I see the problem now, the panner node doesn't increment offset every tick based on current speed.
I checked the code, and the panner just calculates
This is still problematic for me, however I'll just find another way around this. So I'm unsure if this is a definite BUG, or just efficient behavior.
Edit 3: UE-45602 link
Material: Panner uses parameter value SpeedY
Level Blueprint: Update material instance with scalar parameter SpeedY from timeline
Timeline: Ranges from 0 - 2
Level: Fly into trigger area to see bug
With this setup, while the timeline is updating the SpeedY value, the texture flies all over the place. Refer to the video link at the top for demonstration.
I believe this is working as intended. The reason you are getting the flickering is because when you update the value of the panner, it resets but it also is moving because you are setting a value. This constant updating causes the flickering you are seeing, and why it the flickering stops when the timeline is finished.
I think you mistake on Panner function. It must be used with a constant speed, because the time value used for the function is the global time (not a time increased according to the speed and delta time).
For example : if you start your game since 45s and you change your speed from 0.1 to 0.12, it will involuntarily increase the offset of your TexCoord from (0.12 - 0.1) x 45 (and the scrolling will be faster).
The only way to do what you want is to manually increase a time parameter (and not using Time function).
Panner function explanation
Custom Panner function
Dynamic speed blueprint code
answered Jan 19 '19 at 12:46 AM
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