Advanced
Belive it or not, that was the easy part. Now it starts to get complicated!
The strength_schedule is one of the most important setting in Deforum.
When you are rendering an animation, it is going to tell to Deforum how much from the previus frame is going to keep during the generation of the next frame.
This means that the first frame is working as an initial image for your animation to build on, and the strength_schedule determines how much of a “new frame” is benig generated.
THAT’S WHY DEFORUM RENDERS THE FIRST FRAME AT 100 STEPS (for example) and THE NEXT FRAMES AT AROUND 35 STEPS if you set the strength_schedule to 0.65.
If you have 100steps and the strength_schedule to 0.50 for example, next frames will be around 50steps.
minimum value is 0.0 and mximum is 1.0.
this parameter is extreamly sensible, values of 0.05 make a good difference in the result (0.70 to 0.75 for example). Values of 0.01 are fine tuning (0.73 for example).
HOW DOES THIS HELP US?
Lowering this parameter is going to generate more new pixels, this is key when changing prompt or scene or for fast camera movement.
This is going to result in less artifacts and errors in your render and will keep your render “fresh”, but you will have much less coherency (as Deforum is not keeping much from the previus frame) and your animation will look more “giffy”.
Raising this parameter is going to generate less new pixels, this is key for getting good looking and coherents results in your animation, for example in a panoramic shot or a portrait but you will have more errors and your animation will look a bit “sticky”
(as Deforum is keeping more pixels, is it kinda feels like they are stuck to the screen).
Note: the ammount of new pixels that are bening generated is called Diffusion
WHAT DO WE DO?!
Simple: We keyframe it to drop and then come back up at the right moment and with the right value.
As you can see in the example with lower strength schedule there is much less artifacts and the diffusion is able to keep it up with the camera movement
Notes:
Every parameter that starts with “0:(n)” is something you can keyframe
There are many websites that can help you with keyframing, stuff like audio2keyframe, draw2keyframe and more.
https://framesync2-alpha.vercel.app/#
https://www.framesync.xyz/
https://www.chigozie.co.uk/audio-keyframe-generator/
https://www.chigozie.co.uk/keyframe-string-generator/
You can control these settings also with math functions, which we are going to cover in a further tutorial
Set a camera movement.
In this case, the cam is moving from left to right and then rotating right to left at 62 frames to then stop the rotation at 84
Keep the strength_schedule higher when the cam is steady, lower it when the cam moves, and then lower it a bit more when you wanna make and evident change in your scene or prompt.
(I’m a leaving 1 sec of time to allow the diffusion to happen when it generates the new prompt before going back up)
Set your next prompt
EXAMPLE 1
EXAMPLE 2
As you can see, in the first example, the drop was not enough to guarantee the transition we were looking for.
But there is more coherency in the render.
In the second example the transition is much more evident, but the animation is a bit more flickery and the transition itself is really hard.
EXAMPLE 3 WITH A NEW SEED
BOOM!
Pay much attention to how you set the strength_schedule parameter because it can significantly change your animation and make it look very bad or very nice in a matter of nothing.
In this example I'm going to show you how also fine tuning can significantly change your animation
EXAMPLE 4
As you can see the during the rotation the pixels are getting “stuck” on the screen a bit more (creating those artifacts and lines) and the transition is a bit harder
EXAMPLE 5
Now I'm going to show you an example with faster camera movement
ROTATION Y SET TO -3
EXAMPLE 6
diffusion_cadence: 6
What you seen in these examples are “general values” but every situation is different, it's up to you to understand what to adjust and in which situation. The best thing you can do to fully understand this parameter is just test it yourself, keep your settings, right notes down, go step by step.
Keep in mind that you can always stop your animation and resume it adding settings and settings at the time so you can build step by step so you don't get overwhelmed by all these number.
You can also delete frames from the folder of your project if you find some errors or there is something you want to undo.
For example, you can delete the last 24 frames and then when you resume your animation it will restart from the last frame (in numeric order) in the folder.
also the diffusion_cadence is going to impact how the strenght schedule works
Conclusion
Remember, the seed always plays a big role in an animation, learn also to move on