Creating a Rotoscoping Shader

I want to create a rotoscoping shader. I don't know much about shaders but I have some ideas on how to achieve this effect. I think what I need to do is rapidly create randomly generated lines overtime. I'm a little unsure what range I want to go for with the randomization. I also don't know what parameters the randomly generated lines will require. For now I'm going to be using the tree bark shader for the base of my rotoscope shader since I want to go for this scratchy sort of feel with my shader. Am I going in the right direction with rapidly create randomly generated lines overtime or is there an easier way to create a rotoscope shader?

 

Creating those lines within a shade could be fiddly... are you talking a vertex shader which moves line geometry?

 

Yes, do you know what parameters I will need to generate and randomize the line geometry?

 

When you say rotoscopic, do you mean like the modded doom 3 rotoscopic shader?
If so, you can check my aubergines postprocess shaders pack, a combination of 2 shaders will give you this result.

 

More like A-ha's Take on Me music Video or Linkin Park's music video Breaking the Habit. I want to capture the hand drawn feel, jagged edges and constant sense of movement in a shader.

 

That would be charcoal shader with couple of animated brush textures. Previously adding motion blur and some sort of edge detection would improve the effect or make it worse.
Or, charcoal shader with good lighting like; constantly and randomly moving the light(s) around. (This might be easier with a combination of object space shaders and image effects.)
Either way, i never tried so i wouldnt know if it would look good or not.

EDIT: Im talking about the first video.

 

Can the shaders you sell on the asset store be bought individually? The Charcoal shader is the only one I'm interested in.