Tut_BasicSSSsmear
The basic SSS Smear is like a superpowered Motion Blur. But unlike a real camera that needs to encompass any movement during the exposure for each frame and abide by the laws of physics. The SSS system let's you simulate a shutter disc wider than 360 degrees. In the world of motion blurs. To quote Nigel Tufnell, "This one goes to 11".
The basic process is that you move the artwork through a few keyframes at a set time and the VOP exposes each frame while moving the artwork over that curve backwards or forwards to create a smeared long exposure. Then the next frame it does it again with the position being offset each time to create the animation.
Here in this tutorial. We'll be doing that with double exposure that also will show us the artwork in a second exposure with much less smear. Closer to a normal 180 degree shutter motion blur of a regular camera.
As with any animation. You rarely do this by the seat of your pants. You really should think through what you want the animation to do. This is extra crucial with the VOP because there is very little in the way of hand-holding. And like a real film process, you can only really see the result when you get to the end of a run through.
And as you go through this process, you will find that a good amount of mental previsualization will be needed for each step of the way from planning to execution until the final viewable output.
Luckily for us. This first tutorial project is pretty much straightforward. We will want to move the artwork from the distant bottom to the front of upper center of the frame. And we want the trailing smear to be blue. Once at the end. The smear should shrink into the logo and the image should flare up a little before settling down at a normal exposure.
For this project, we will need only one piece of artwork. A simple in white on a black background. You can use basically any dimensions. I have so far tested it with up to 4096 pixels in each dimension and the VOP seem to handle them just fine. If you want to use your own logo. Just save it as a standard PNG. No alpha channel transparency. That doesn't exist in the world of film printing anyway. The bright pixels are what would be considered transparent, because it lets through light. But in this case. We'll be working on a black background so it's easier to think of black as transparent on the final exposure.
If you don't have an artwork you can use one provided here: LINK
When you have the artwork ready. Upload it to the Projection Mag. The VOP will caution you a little that doing an upload will delete any artwork that's already in the Projection Mag.
By the way. If the naming convention confuses you. For the purposes of this tutorial. you can think of the Projection Mag as a backlit animation desk. The artwork are on animation cels. The upcoming Projection Gel is the color of the light in the desk.
Before we do any animation we should go over the other settings that you can use for a job. They are editable before a sequence execution (the big green button) but don't actually change during the run. So we consider them constants during the run. For this tutorial we can use these settings:
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PROJECION MAG
- Ref Z(Fit) - Leave this at -1.0
- World Scale - Leave it at 1.0
- FIT FOV - Press it. This will make sure that at the Ref Z distance, in this calse, -1.0, the artwork we uploaded will precisely fit the camera view. You should see the World Scale change to some other number. This number can be nudged if you want to force some other scale. But leave it at the auto-calculated value.
- PROJECTION BIPACK We won't be using this section at all during this tutorial so leave it unused. If you accidentally uploaded something to it. Just hit the NUKE button for it. It will delete the unneeded image.
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HARDWARE CONSTANTS
- FOV - Keep it at a default 45 degrees. It's adequate for our job.
- Cam Res - This is a tutorial so we can keep it at half res at 2028x1520. It's still detailed enough for a 1080p final master.
- FPS - Keep it at a regular 24 for normal film speed
- GAIN - Depends a bit on your hardware. But I'll keep it at 1.0. If you find that you need it brighter but can't do longer exposures. You can bump this a bit. But remember that you also raise the noise floor of the image. And that matter a lot when doing multiple exposures as each new exposure adds its noise as well to the latent image.
- AWB R and AWB G - You can actually leave these as well because we won't use the color mode for this tutorial.
- Comp - Let it be compressed. It'll be good enough. So set it to ZIP if it's not already set there.
- Mode - Set it to SSS. We're not going to do any advanced multidimensional movement in this one.
- Mono - Check this box. It'll make things easier for this particular job.
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PROJECION MAG
When all those are set, you should have something like this:
You can now, by the way, check the difference between the buttons called PROJ PROBE and CAM VIEW. Let's do that.
Press the PROJ PROBE button. If you have the terminal output running visible you should see it start having some activity as it prepares the image, flash it briefly on the HDMI monitor. And then you get the preview on the GUI. In this case, you won't see much difference from the first upload.
Press the CAM VIEW button and if the camera works and is lined up correctly. You should now see the terminal come to life again. Artwork get flashed on the screen. And the Preview window should then change to show the image that the camera took.
Admire that beauty. Then we'll start making it look even cooler.
As the Exposure sheet should be empty from the start you need to add a keyframe to start adding the movement. Click the + ADD SSS KEYFRAME button to add the first keyframe.
Now you should see the row of inputs:
Now we'll move the artwork into the distance. With the FIT FOV button earlier we established that at a distance of -1 it is fitting the HDMI screens borders perfectly.
So we'll move it to a distance of 10. That's done by changing the third value of the first POS (X,Y,Z) input. Make it 0,0,-10. Then hit the PROJ PROBE button to see the result in the preview.
What you can also notice is that there is grey around the artwork when we watch it on the PROJ PROBE. That grey will not be on the HDMI monitor. Do not worry about that. The grey there is just to make it easier to judge where the monitor ends and the rest of the GUI is.
Now that it's in the distance. We can move it down. So let's do that. Add a -5 to the middle value of the position input. So it now is 0,-5,-10.
If you now hit the PROJ PROBE button you should see that it has moved off screen below.
Look at the keyframe inputs. See the white box called CG? That's not Computer Generated Images. Well, technically this whole things is. But in this case CG stands for "Camera Gel". And it's there to let you tint the resulting exposure in a way like when you put a color filter, or a gel, on the cameras lens. So click it and make it blue.
- For EXP we'll use a 4 second exposure. Enter 4.0 here
- For SD we'l have 10 frames of Smear Distance. So enter 10.0 there.
- For PH we'll use 1.0 so that the smear trails behind the artworks position.
Since it's still outside view. Let's make it visible again.
Put in a new keyframe by clicking the + ADD SSS KEYFRAME. And notice that the VOP is helpful by making sure that most of the inputs carry over from the last keyframe. This is to help speed up the setup of a job.
Go ahead and fill in the new numbers.
- FR - We'll set the second keyframe two seconds into the future. So with our 24 fps project, that's 48. So enter that in FR.
- POS (X,Y,Z) - move it up to the center of view by making the Y 0. And move it a bit closer to the screen. Use -3. So the POS becomes 0,0,-3. Hit the PROJ PROBE to check the result.
Now. If you followed the instructions here slavily. You probably saw that nothing showed up. That's because I neglected to talk about the Frame and Sub (0-1.0) system.
When we are using the PROJ PROBE and CAM VIEW. The VOP uses the inputs of the Frame and Sub (0-1.0) to know what it is you want it to show. In video editing terms. These two are your preview playhead. We have been looking on frame 1. And when we made the new keyframe, we haven't actually moved the preview playhead. So go ahead and do that.
- Frame - as it suggests, sets the frame of the probe. Set it to 48 so we can see where we are expecting.
- Sub (0-1.0) - This shows where we are going to have the artwork on a specific point of the smear. Put it at 1.0. This is to set it to the end of the smear.
If we now press **PROJ PROBE, we should see the artwork in the middle of the preview monitor.
Go ahead and try using the Sub (0-1.0) to see the artwork on several parts of the smear. 0 is the start of the smear, 1.0 is the end. And in between you can look at any part.
This is the point where we can look at the VOP doing a smear. Because the VOP has enough data to know where to move things. Press the CAM VIEW button. And look at the HDMI monitor doing its thing.
What you should see is the logo flying towards the camera in stark black and white.
But we wanted it blue?
Well, look at the preview monitor. The VOP takes the smeared image that was exposed on the camera. THEN it applies the camera gel. So on the preview monitor you'll see the tinted image. This is what will be pushed to the LIME system in a real execution.
But I want a little more action here. Make it spin a bit.
In the second keyframe's ROT (P,R,Y). Set the last bit to 0.5 so that when it reaches this second keyframe. It has spun upside down. Then hit the CAM VIEW again. And you should see the smear rotate slightly.
Do the third keyframe now.
- FR - put in 96. That's 4 seconds into the keyframe.
- POS (X,Y,Z) - move the artwork a bit closer. Put in 0.0,0.0,-1.5
- ROT (P,R,Y) - Rotate it further so it's the right side up.
- CG - Let's make it white by this point. It'll help later on to make it extra bright.
Move the probe to frame 96. Hit the CAM VIEW again. See that now the preview shows the logo slightly smeared, rotating and in stark black and white again.
We are on a roll here. We will be adding in the fourth keyframe and do these edits to this new keyframe.
- FR set it to 120. One second after the last keyframe. 5 second total runtime now for those keeping count.
- EXP set it to 8.0 for 8 second exposure to make it even brighter.
- SD set it 0.0. We are done with the smear here.
No real need to watch this one. We'll go ahead and do the last keyframe.
Same deal here. Add the keyframe and fill in the things that need to change. We'll do a 5 second fadeout back through blue.
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FR - set it to 240.
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CG - set it back to blue.
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EXP - set it to 0 so it goes black.
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Frame - set it to 220 and see that the artwork now is very dark blue. Almost black.
Here's what you should be seeing on the screen
Just in case something is already in the CAM MAG. We can just hit the button at the top right called NUKE MAG. Please do NOT touch the NUKE JOB Button, if you do. All of the data we've put in gets removed. And as the warning popup says. It's not reversable.
But if this is your first time running the VOP Go ahead and nuke the cam mag. For the first exposure. You want it to be empty.
GO ahead now and do the first exposure now. Find the big green button named EXECUTE SEQUENCE
Hit it.
Now just sit back and enjoy the show.
On the GUI nothing really changes. Except that the status bar comes to life. The line shows the jobs completion. And you also see an estimated total file size and ETA time. And yes. You are reading that right. Our simple 10 second final runtime project's first exposure will take at least 30 minutes.
This workflow is slow and tedius. And it's part of why I'm loving it.
While we are waiting for that first set of exposures to be done. We can have a look at the monitor. You will see the loop that the VOP runs for each frame.
- .5 seconds of black - This is to make sure that even if there's a few milliseconds of drift somehow in the sync between the Pi and the camera and the monitor. The camera will catch the whole smear movement.
- x seconds of smear exposure - This is the number you set as EXP in the Exposure Sheet.
- .5 seconds of black - Like in point 1. This is just for some error margins in syncing.
And you can also look into the folder of the Pi where you have the VOP installed and look at the files as they populate the CamMag. It's good both for curiosity. But also to check that things are running smoothly.
And you can also follow the progress in the terminal window you used to fire up the VOP in the first place
And as you follow the flashing on the HDMI monitor. You'll see how it flashes the artwork faster and slower when it goes through the sequence. Always with white light. But remember. The color gets added in post in this case. By the very end. the flashes are extremely short.
When it's all done. We can finally look at the smear in motion.
The status bar will get a link called VIEW WORKPRINT. Click it to get access to the workprint of the latest exposure. It is a quickly produced mp4 file that is only for preview purposes so we know if we can proceed to the next exposure.
I'm not sure about you. But I am certainly happy with the result.
We'll do the second exposure shortly. We'll just have to adjust a few inputs on the exposure sheet.
These are:
- CG We'll make all of them white.
- SD Make these 0.5 to simulate a standard half moon 180 degree shutter wheel motion blur. The smear will be minimal per frame. Keeping the beautiful logo in reasonable clarity.
Go to Frame probe point at 46. Do a CAM VIEW preview. It'll be very uneventful. But we just want to check to see that it is. Notice however that as we only peak at this before the LIME system. We don't see the blue smear. Apply your own imagination to previsualize what the combination of the exposures will be.
I'm pretty sure this is all we have to adjust. So we'll run through the second exposure. This is a destructive process. So if we arent happy. We'll have to start all over again. Hit the big green EXECUTE SEQUENCE
Like with step 18. You can look at the things it's doing. Looking at the files. You won't see the artwork get into view until about the frame 16.
When things are all done. You can use the VIEW WORKPRINT again.
And that's it for this Tutorial!
Feel free to play around with what you now know. And if you want a high quality image sequence for a project. Just go to the CamMag folder and pull the TIFF's from there.
Fun tip: All the workprints are saved in the workprints folder. So you can return and compare each workprint.