Motion Blur in Animation.

[starstriker32]

Hello. I was just wanting to hear peoples thoughts on motion blur in Animation? Specifically 2D style Animation and the type of style that Moho does.
I'm currently working on a Christmas themed action short film and I have always liked motion blur especially for a project like this but I was wondering if other people use it or if they hate it in animation. Would be great to hear peoples thoughts.

[slowtiger]

I use it, but not in Moho - instead I create a drybrush effect in TVP.

[Greenlaw]

I typically use a post-applied motion blur effect in compositing, for example, Twixtor or Photoreal Motion Blur in After Effects. This is a simulated motion blur based on internal pixel tracking, and It's faster than rendering Motion Blur directly on the frames. Unlike rendering with motion blur, the settings for these effects are fully interactive, and the result usually looks great!

Applying a Motion Blur effect in post is very common in 3D animation because the 3D program can embed what's called a Motion Vector channel, and any compositing program (Nuke, Fusion, or After Effects,) can use this data to apply 'real' motion blur to any layer or the entire comp, after any other layers and comp effects have been added. This is a notch over the above technique, because it's based on actual motion data, not pixel interpolation.

Unfortunately, Moho doesn't export motion vector data. If Moho ever supports the EXR format, I hope it can also start embedding this buffer data (along with depth, normals, and Shape/Style IDs.)

All that said, it's not typical to use photorealistic motion blur in 2D. Traditionally, the animator cheated the effect by drawing the 'blur' in what's called Smear Frames. I sometimes create 'smears' using the Magnet Tool or a Mesh Warp.

Another trick is to overlay animated speed lines. I used this technique a while back when I did development work for the Bad Guys TV special on Netflix.

[MrMiracle77]

Moho's motion blur feature seems to apply multiple additional transparent layers, which greatly increases the processing overhead since each image is its own layer. On the few times I've tried to introduce motion blur in a sequence, I'll import the individual images into a separate program and smear the image manually.

However, I've used the motion blur feature for other things. It's good for making trippy, psychedelic effects in shorter sequences.

[NanotechBeasts]

Not sure how I feel about it. I was considering learning how to use it on a head turn after I do my best on it to try to cover up my mistakes but I could see how helpful it could be in more natural action based scenes where I actually want to use it. Last blur effect I did was a lense focus blur and I actually got so frustrated with the program that I used Photoshop because it was a few frames for a gif simple image not video to get the job done I guess I really play around with it more.

[slowtiger]

There's 2 kinds of motion blur.

One is the "normal, realistic" blur which would occur when using a live action camera with fast movements: the object moves while the shutter is open, creating a blurred trace of that object on film. In animation this may be used in very fast movements with a bigger distance between positions from frame to frame, and this is the kind of motion blur several software solutions try to emulate. My advice would be: use it sparsely.

I find Moho's solution not satisfying, but also I don't want to use any other program just for this effect. In the few cases I needed it I prepared the blur part in Photoshop: by using a frame from Moho and apply a strong directional or circular blur on the moving parts, then erasing the leading half of it. These bitmaps I placed over the animation in Moho.

The second kind is much more 2D animation-like. Traditionally it would've been done with drybrush on cel. Your option in Moho again is to paint it outside of Moho in a bitmap program. This is the kind of blur which would be used to indicate zany, exaggerated motions and faster-than-light zips. Your overall design style needs to fit this.

There's also distorted objects and multiples, in fact this whole field requires a study on its own ("Movements which would need multiple frames crammed in just one 101"). I like it very much and apply it as often as possible.

[NanotechBeasts]

There's 2 kinds of motion blur.

One is the "normal, realistic" blur which would occur when using a live action camera with fast movements: the object moves while the shutter is open, creating a blurred trace of that object on film. In animation this may be used in very fast movements with a bigger distance between positions from frame to frame, and this is the kind of motion blur several software solutions try to emulate. My advice would be: use it sparsely.

I find Moho's solution not satisfying, but also I don't want to use any other program just for this effect. In the few cases I needed it I prepared the blur part in Photoshop: by using a frame from Moho and apply a strong directional or circular blur on the moving parts, then erasing the leading half of it. These bitmaps I placed over the animation in Moho.

The second kind is much more 2D animation-like. Traditionally it would've been done with drybrush on cel. Your option in Moho again is to paint it outside of Moho in a bitmap program. This is the kind of blur which would be used to indicate zany, exaggerated motions and faster-than-light zips. Your overall design style needs to fit this.

There's also distorted objects and multiples, in fact this whole field requires a study on its own ("Movements which would need multiple frames crammed in just one 101"). I like it very much and apply it as often as possible.

Thank you for the breakdown explanation. It is a helpful way to look at and understand it.