Split Scan Simulations

[John Dalton Synthetik Software]

There's recently been some discussion of split scan animation techniques here. As i mentioned in the discussion, it's pretty easy to simulate slit scan animation techniques using multiple layers and layer position keyframing in Studio Artist 3.5.

A simple example is to take a source movie and generate a single image that captures the movement in the movie by simulating a slit scan of the movie as it plays. The movie source i used for this test was a car jump where the car moves from left to right over time.

I've attached the end result static image and the paseq i used to generate it. You will need to run on layer playback in the paseq configuration preferences. And you need to setup 3 layers as i specify below for this to work properly.

I generated a quick example using a PASeq that uses 3 layers. Layers 1 and 3 are full size. Layer 2 is a vertical slit. Layer 2 is position keyframed to move from the left side of the canvas to the right side of the canvas across the animation to build up a single composite image. Layer 1 is used to build up the final image. Layer 3 is used as an intermediate source buffer.

The PASeq has 4 steps. The first step sets layer 1 to white and then is muted after keyframe 1. The second step sets layer 3 to the source image. The third step captures layer 3 into layer 2. You can record this by choosing layer 3 as the current layer and option clicking the record button on the left side of layer 2 in the layer palette. Since layer 2 is a narrow vertical slit you only capture a narrow view into layer 3. PASeq step 4 prints layer 2 onto layer 1 using the Fixed Image ip op with min compositing.

After recording the PASeq you run animate for the length of the source movie. The layer position keyframes for layer 2 sweep the narrow vertical slit across the draw canvas over the course of the animation. Depending on the size of your canvas and the length of your source movie you will need to adjust the horizontal size of the slit accordingly. You can use the Geodesic Interpolation ip op to fill in any vertical white cracks after you run the animation.

[John Dalton Synthetik Software]

Since i like to show off version 4 i should point out that you can generate something somewhat similar by loading a source movie and just choosing one of the new image processing operations and hitting action. Example attached.

It's not exactly the same thing but a lot quicker to generate.

[John Dalton Synthetik Software]

OK, i decided to dive in and add a new feature to version 4 that is an exact slit scan simulation. Result is below for the source movie i used above. This is one action button push, so it's a lot faster than how i describe you can do it in 3.5.

What i love about 3.5 is that it's very much like a swiss army knife, there's usually a way to do something in it when you get an idea for a particular effect. But of course nothing beats just pressing a button to get the effect. If i had more frames in the source movie i could get a smoother motion effect, ideally you want at least as many as you have horizontal pixels in the canvas.

[John Dalton Synthetik Software]

2 more examples using the new slit scan simulation. The first is the car sequence scanned bottom to top with a horizontal slit. The second is an airport walk sequence scanned top to bottom with a horizontal slit.

[Montgomery Zatt]

Wow- I casually mention this and now it's a feature (in 8 hours!!!)- you're incredible John.

[Frank N]

Hi John, as a try I used your "carJumpSlitScanPASeq" on a video. I mean input (source) as well as output (result) was a video. I hit the command Process Source Movie with PASeq to Movie.

So I am nor really sure what happend. It seems that the first frames of my processed movie kept being the same as the source frame, the second frame is frame 1 plus frame 2 in one (like a classical double exposure), frame three is the resulted frame 2 plus source frame 3 and so forth.
But this would be not what it's supossed to be a slit scan.
But as I said I am not sure anyway what exactly happened. I guess you can tell:-)

Thanks again in advance

[John Dalton Synthetik Software]

Sounds like maybe you didn't set up layer 2 to be a 1 pixel vertical or horizontal slit. It needs to be 1 pixel wide and then you need to keyframe its movement over the course of the paseq.

[Frank N]

For the test I just used your PASeq like it is, I did not change any settings.
I will check.

[Thorrific]

Wow that's fascinating John, thanks!

[Thorrific]

ok I tried it and I couldn't make it work, I have a 640x480 size movie, timeline anim frame # set to 640, layer 2 is 1 px vertical slit, I tried keyframing layer movement in layer window with the i hotkey but it didn't seem to work.

Should layer 2 movement be keyframed into your paseq? In one of the existing steps or on its own?

[Frank N]

Hi Thorrific, late night in Germany and I go to bed. I'll check tomorrow.

Best, Frank

[Thorrific]

Ok I figured it out, either I wasn't moving the layer 2 enough or I had moved it too much... it seems like it is working now, I will post the resulting image soon.

[Thorrific]

Here it is, I used John's paseq and keyframed the movement of layer 2 from left to right across the 640 frames, put a little Image Compressor on it to brighten it up and whopee! Thanks John, I never realized this kind of thing could be done with Studio Artist!