Ingmar Franz (duerer)

7 answers · asked · Lesson: Graph Editor and Interpolation · Course: Fundamentals of Animation in Blender

"Generator Modifier" on F-Curves for Animation Keyframes different to same Modifier for Drivers?

Do I see it right that the "Generator Modifier" on F-Curves for "Animation Keyframes" behaves different than the "Generator Modifier" for Drivers? For "Drivers" the input seems to be put into the "X" value of the default "Polynomial" (0 + 1x):

Active "Generator Modifier" an keyframed translation along "Global Z" with "Linear Interpolation:

For the "Animation Keyframes F-Curve", the "Generator Modifier" seems to replace the "Keyframed F-Curve":

a) Inactive "Generator Modifier"

b) Active "Generator Modifier"

  • crew

    HI Ignmar,

    I'm not entirely sure what your question is.

    Yes the Generate curve modifier will replace any keyframes you have in the Graph Editor (GE) or Drivers Editor (DE).
    No it doesn't work differently in the GE to the DE.

    It does display the polynomial in a non conventional way though.
    When I was at school, we learned the polynomial order as "y=mx+c"
    But in Blender is is displayed as "y = c+mx"

    This is mathematically the same though.

    Let me know if I didn't answer your question (as I'm not entirely sure what you were asking haha)

  • Those two are indeed exactly the same like waylow said.

    The Driver version is a straight line going through (0, 0) and (1, 1).

    The other goes through (0, 0) and (20, 20).

    So, the only thing that makes it look different is the scale of the graph ;)

  • waylow and spikeyxxx Thank you both for your answers. I was just a little bit confused because I thought until now a "Generator Modifier" could be used to speed up an animation with  for example "y = 2x"   in order to make it run at double speed. I further thought that the "X" in the "Generator Modifier" of a "Driver"  takes the value of the "Scripted Expression" as input for "X" and outputs the desired recalculated value. What sense would it make for a Driver to completely ignore the input from the driving property? Of course, I could activate die "Additive" button for calculating the sum of the old  curve and the polynomial but I assumed with my question that this button is inactive so that new value replaces the old one.

  • Agreed, the term Modifier suggests that it would modify the curve. In stead it generates a curve. The Tooltip is more descriptive:

  • I think the confusion partly came from the fact that a "Generator Modifier" can be used for example for inverting a linear graph representing a slider input which is linear as well (if the scripted expression uses the default setting) so that I didn't realize that the "Generator Modifier" created a completely new graph instead of recalculating the old graph by mirroring it on the Y-axis.

  • Thanks, spikeyxxx, once again😊! Now, it's clear 😀!

  • spikeyxxx The Blender developers will probably argue that these "Modifiers" can be really used for the modification of an input by pressing the "Additive" button. But the default setting (which was the basis for my question) has this button inactive.