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# offset start on formula deformer

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 offset start on formula deformer on May 23, 2019 at 6:23:16 pm

Hi!
I'm sure there is a way to offset the start of a simple formula sin animation, but I don't know how to tweak t to tell the wavy animation start at a giving frame. I come from After Effects echosystem, and I don't know how to tweak the formula to add an equivalent to valueAtTime
or maybe via xpresso? (no idea neither)

any ideas will be much appreciated!

 Re: offset start on formula deformeron May 23, 2019 at 7:03:20 pm

A few ideas:

If you want the formula to be active but not animating, and then to begin animating at a certain frame, keyframe the project time from 0 to 1 at that frame.

If you want the formula to have no effect, but then ramp up, leave the project time at 1 and keyframe the Strength from 0 to 100% beginning at the desired frame.

Alternatively, if you want to jump from no effect to full effect, keyframe the "Enabled" setting in the Basic tab between successive keyframes.

Hope this helps.

 Re: offset start on formula deformeron May 23, 2019 at 7:20:29 pm

Thanks Jim for the ideas!
Now I that have been messing around with adding decay to make it like a water drop decaying to 0, plus your fantastic tops to make the formula on/off, the issue now, is that that formula seems to be generated at frame zero, so none of the options mentioned below seems to work (even animating the enabled status didn't make the trick), so I'm back again to trying to mess with the t value to make it not start until a desired frame.

This is the formula I'm playing with

which is a variation of some of this Dan Ebbert's decaying sine wave gold snippet:
amp*Math.sin(t*freq*Math.PI*2)/Math.exp(t*decay)

A side solution may be linking the t value in the exp(t*1-u) so its always 0 until I say to be 1 (or some non zero value)
But it should be a better and simpler solution, I guess?

 Re: offset start on formula deformeron May 23, 2019 at 8:11:04 pmLast Edited By Jim Scott on May 23, 2019 at 8:11:50 pm

Hi Peter,
Any chance you could post your project file? It would make it easier to troubleshoot if we could see it.

 Re: offset start on formula deformeron May 23, 2019 at 9:01:21 pm

hey!
yes, here it is!
Its very simple, just a plane with the formula and the decay snippet on it

13367_decaywave.c4d.zip

many thanks!

 Re: offset start on formula deformeron May 23, 2019 at 9:16:42 pm

Thanks Pete,

My brain scrambled your original post, so I was making suggestions based on a formula effector and not a deformer, which rendered all of my suggestions rather meaningless. Sorry for the confusion. Let me look at this and get back to you.

 Re: offset start on formula deformeron May 23, 2019 at 9:18:56 pm

oh! my bad! I should have been more specific!

 Re: offset start on formula deformeron May 23, 2019 at 10:10:25 pm

Nope, that was completely my mistake. You distinctly wrote "deformer," and for some reason I set up an example with an effector on clones to experiment with because I had been working with some effectors earlier in the day. It must be old age.

 Re: offset start on formula deformeron May 23, 2019 at 10:55:49 pm

I think that you are right that using xpresso is the way to go. Unfortunately that is an area where my ignorance really shines so hopefully someone else can chime in. I'll keep plugging away and let you know if I come up with something.

 Re: offset start on formula deformeron May 24, 2019 at 2:21:55 pm

thanks for your help! it's been quite helpful indeed, as a start to know where to look!

 Re: offset start on formula deformeron May 24, 2019 at 2:57:20 pm

I'm not sure if this is what you are looking for:

-Reduce the "t" to small value like .9
-Put the Falloff weight in 100%.
- Add keyframes the fall off Position.

Here is an example.

13368_examplewave.zip

Hope that helps.

Good Luck

Imagination is the best tool...

 Re: offset start on formula deformeron May 24, 2019 at 8:02:30 pm

Very clever Emir. Thanks for the example.