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Mops Delay wont work

Posted: Sun Jul 26, 2020 7:44 pm
by ginz
Hello,

I can't seem to make the delay mop work. I have a very simple cluster of mushrooms (temp proxies) that are scattered on a tube with a transform animation from 0 to 1 in 72 frames. I want to control the start of the transform animation on the instances with a falloff. No matter what I try the delay mop doesn't delay the timing of the animation, I'm just getting all kind of weird behaviors. I'm sure I'm doing something wrong just couldn't find anything about it. Attached is the project file.

Thanks for your help!

Re: Mops Delay wont work

Posted: Sun Jul 26, 2020 10:05 pm
by toadstorm
Hey there,

The issue here is that MOPs Delay can only delay the transformation of packed primitives, the time index of packed sequences, or the individual points of an animated polygon mesh. You're trying to delay animation that's been done in SOPs and *then* packed by the Instancer, and MOPs Delay can't properly read that sort of thing unless it's been cached to a sequence first.

I just wrote your growing animation to disk, then loaded it into the Instancer in "File" mode, making sure to set the sequence length properly.

Re: Mops Delay wont work

Posted: Sun Jul 26, 2020 10:29 pm
by toadstorm
One other thing I should mention: when time delaying animated sequences, never trust the viewport. It will lie to you about timing. The only way to be certain is to either unpack or render a frame and verify that the delay is happening as expected. This is some kind of Houdini viewport bug that I unfortunately can't work around, but you can definitely still render the delayed sequences without unpacking; it's just for the viewport.

Re: Mops Delay wont work

Posted: Mon Jul 27, 2020 2:16 pm
by ginz
toadstorm wrote:
Sun Jul 26, 2020 10:29 pm
One other thing I should mention: when time delaying animated sequences, never trust the viewport. It will lie to you about timing. The only way to be certain is to either unpack or render a frame and verify that the delay is happening as expected. This is some kind of Houdini viewport bug that I unfortunately can't work around, but you can definitely still render the delayed sequences without unpacking; it's just for the viewport.
Hi, Thanks for the reply and the file. You are right! it's fine only after final render not in the viewport, strange, hopefully you'll find a workaround it.

Thanks for your help on this! and keep up the great work these tools are so essential!

Re: Mops Delay wont work

Posted: Tue Nov 03, 2020 3:01 am
by secretspaces
Hi there, thanks for providing this great toolset!
I have another question regarding the delay modifier:

-If I use a vex expression, can I set the 'Delay Amount' slider to 0?

-I currently have the following expression "delay = float(@ptnum) * 16;",
but am just getting a uniform delay of the falloff attribute animation.

//edit:
I found out from the delay example file, that the falloff acts as a mask and the delay is applied to transform animation.
So I made a @pscale animation and delayed it with a @ptnum based falloff and then derived a new falloff from the delayed @pscale animation.
Hacky and working, but is there possibly a more direct approach?