increase motion blur over time?

[Curious Turtle]

Motion blur in the normal scheme of things cannot be animated and usually you wouldn’t want to. The parameters are safely tucked away in the composition settings.

What you can do is to use other filters to either replace or beef up the effect that you’re going for. It could be a simple Directional or Radial Blur or a slow but effective CC Force Motion Blur. It all depends on the effect that you want, and the direction the object is travelling in.

Hope that helps,
Ben

Curious Turtle Professional Video
Training | Editing |Support

http://www.curiousturtle.com

[Clayton Light]

Thanks Ben.

I’m trying to make something spin around and blur more over time. I know it’s an unusual situation.

I tried CC Force Motion Blur, but it didn’t seem to work. I’ll try again.

Clayton

[Joey Foreman]

Since you can’t keyframe the shutter angle, I can think of two possible workarounds. I tested both and neither gave really spectacular results on a masked solid, but depending on what you’re applying the blur to the results might be improvable with additional futzing.

Workaround 1: Render out the solo-ed object(+Alpha) with a small amount of motion blur.
Crank up the shutter angle in comp settings and bring in your rendered item. Place your now heavily blurred layer over the rendered layer and animate its opacity (0-100) over the length of the animation.

Workaround 2: Precompose the layer to be blurred and instead of using motion blur in the timeline, apply Timewarp. Leave the speed at 100%, turn on Timewarp’s motion blur and keyframe its shutter angle over the length of the animation. Theoretically this should look nice, but it looked bad on a masked solid for some reason.

Joey Foreman
Editor/Animator
Nowhere Productions, Athens, GA

[Joey Foreman]

It will naturally blur more as it speeds up. Just slowly ramp up its rotation rate. You can do this with an expression (sorry, can’t help you there) or you can use exponential scale.
Set an initial rotation angle keyframe – but don’t start with zero, start with 1,change its type to ease out, then move ahead in the timeline and set a second keyframe with a higher number like 20. Then select your first – then second keyframe and apply Keyframe Assistant>Exponential Scale. RAM preview then adjust to taste. You’ll have to undo or delete the gazillion keyframes that E.S. creates if you want to change the numbers, then apply it again.

Joey Foreman
Editor/Animator
Nowhere Productions, Athens, GA

[Darby Edelen]

The Graph Editor provides an easy way to ramp up the speed at which a value is changing.

It’s an involved tool that I can answer specific questions about, but I think Adobe’s help would be a better place to start:

https://livedocs.adobe.com/en_US/AfterEffects/8.0/WS3878526689cb91655866c1103906c6dea-7e0e.html

Darby Edelen
Lead Designer
Left Coast Digital
Santa Cruz, CA

[Aharon Rabinowitz]

[Clayton Light] “I tried CC Force Motion Blur, but it didn’t seem to work.”

Add an adjustment layer to the top of the comp, and then add force motion blur to that layer. It won’t work the way you are doing it.

See this tutorial for more info on the effect:

https://library.creativecow.net/articles/rabinowitz_aharon/force_blur.php

Aharon Rabinowitz
Email: arabinowitz (AT) yahoo (DOT) com
All Bets Are Off Productions, Inc.
Creative Cow After Effect Podcast
Internet Killed the Video Star: A Guide to Creating Video for the Web

[Joey Foreman]

Darby’s right, the Graph Editor is a hundred times easier than messing around with exponential scale.
Just set a starting and ending rotation keyframe.
Open the graph editor, set an ease out on the starting keyframe and then pull the right ease handle out a good bit and give it a slight lift. You can adjust the left handle of the second keyframe as well if you want.
You’ll probably want to set a third keyframe as well to sustain the rotation speed.
God Luck.

Joey Foreman
Editor/Animator
Nowhere Productions, Athens, GA