Motion blur of motion loop <1 frame

I’m animating a huge fly to be killed in my huge bug zapper, and I’ve run into a problem I foresaw, but did nothing about. I’m trying to figure out how best to do the wings. On video (and in real life for that matter), a fly’s wings will beat so fast that they will complete a whole cycle in less than a frame (often more than one cycle too!), so this introduces quite a lot of motion blur on the wings, and as we all know Blender kind of chokes when it comes to a realistic motion blur. Vector blur is completely useless here because it completes a whole wing flap cycle in exactly one frame, so the wings are in exactly the same spot in frame one as they are in frame two, but in between those two frames, they’ve been haulin!

I’ve been trying the old fashioned multi-sample motion blur, and that seems to be working alright, apart from taking forever (at 16 samples… the max). I’m thinking about just rendering the scene at 3x the frame rate so I can effectively get a mythical 48 sample motion blur, instead of the measly 16 we’re forced to use.

If I slightly change the time it takes for a whole cycle to complete (it was at 1 frame in my original post) to .8 frames, it does that cool aliasing thing! (Like when you can see a car’s rims rotating backwards on the highway). Before, the problem I was having was that the wings, even with the blur, looked EXACTLY the same in every frame.

Can you perhaps answer my noob question? :slight_smile:

Where do you enable this motion blur? I saw the respective setting on a render panel, but I suspect you’re talking about more than one motion blur type available in blender. Can you briefly point me to the place it exists? And I’ll read the manual then :slight_smile: Thanks.

For the traditional motion blur, you simply enable the ‘MBLUR’ option in the render panel, and the number enabled under ‘OSA’ is not only the antialiasing level (assuming you have OSA turned on), but it’s also the number of subframes that are blended together to make the final image.

There is another type of blur that is MUCH faster, but gives very inaccurate results. It’s called the vector blur. You have to set this up using the compositing nodes. Enable the ‘Vec’ pass, and you’ll notice a node on the render layer appear called ‘speed’. Now add a node ‘filter->vector blur’. Plug them into their respective slots, and voila! You have a blur! It works by doing a directional blur on the rendered image based on the velocity vectors and z depth that you give it, so it’s by no means accurate (if the camera moves quickly, you get no blur for example). It’s best for small moves.

Great! Thank you for information :slight_smile: