How To Offset Start Frame of a Loop

[Mark Walczak]

Hi Everyone,

This seems like a very simple task, but I could use some help thinking through it.

Basically, I have a clip of a 10 second loop that is being used three times in my comp. I would like to add some variety, and have each instance of the loop start at a different frame and loop seamlessly.

When dealing with pre-rendered clips, I simply loop the clip in the interpolation settings and slide it in my timeline. When dealing with comps, however, things get a bit more complicated.

My question is whether or not it’s possible to insert an expression into a layer’s time remapping attribute that allows you to simply slide the start frame of a loop and have it play out.

Let me know if this isn’t making sense, and I’ll be happy to clarify.

Thank you!

https://vimeo.com/explosivegraffix

[Dan Ebberts]

Something like this maybe:

s = Math.round(effect(“Slider Control”)(“Slider”)); // start frame
f = timeToFrames(time);
d = timeToFrames(source.duration);
framesToTime((s+f)%d)

Dan

[Mark Walczak]

Dan,

This is EXACTLY what I needed. Thank you so much!

I follow your logic through the expression, but could you tell me what “%” does in the last line?

Thank you!

https://vimeo.com/explosivegraffix

[Dan Ebberts]

% is the JavaScript modulus operator. It gives you the remainder of a division operation, so it’s what generates the looping value.

Dan

[Mark Walczak]

Ah – perfect!

https://vimeo.com/explosivegraffix