If you’ve seen my presentation from the 2017 Blender Conference, you saw a transition effect I did for the TV show “Star” (check out 15:45 minutes into my presentation). The director wanted a transition into the mind of an actress to show what she’s thinking about, and described it as if a pencil is poking through from inside her head, and then the frame tears apart from that point, revealing the next shot underneath.
At work, in the fall of 2016, a supervisor and producer came to me one morning and asked if this was something Blender could do, and then casually mentioned they were hoping to have something to show the client by lunch time. I said I was sure Blender could do it, but I wasn’t sure if I had the knowledge or skills. I took a few moments to look around online to see what kind of tools, options, or tutorials there were for tearing cloth, and found ClothFX. I instantly purchased it and started trying it out.
What a neat tool! Something that really surprised me about it was that it’s not really doing anything completely new in Blender. At least, I don’t think it is. What I mean by this is that it’s not creating a functionality from scratch, it’s using all Blender’s built-in tools in a very clever way, and automates and simplifies the process of setting it all up by using helper objects and making it all work with just a few easy buttons. A very impressive feat by the tool’s author Jesus Alberto! Just the fact that he figured out how to do this is amazing, not to mention that he came up with a way to make it really easy!
So here’s a tutorial showing exactly how I used ClothFX to achieve the effect. It’s not complex at all, and I’m the first to admit I don’t know everything there is to know about using this tool. In fact, I only know the bare minimum I needed to accomplish the effect! But hopefully this can be a good introduction for smarter artists, and hopefully they’ll also do tutorials so we all benefit.
Buy the tool HERE, and check out the author’s tutorials HERE. It is a paid tool, but before you freak out, it’s not that much. First, in the world of vfx plugins, $45 is nothing ($28 if you hurry and buy it before April 20!). And second, someone who knows a lot more than me about coding spent a lot of time making a super cool tool. I’m happy to pay them for their time.
Grab the sample images and check out the tutorials below! Right click the names of the tutorials to download the videos directly.
Tutorial 1 – ClothFX and setting up the simulation.
Tutorial 2 – Assigning the textures and rendering.
Tutorial 3 – Basic compositing of the transition. NOTE – In the video, I forgot to set an end frame for the final render. I ended up setting it at frame 60.
And there’s even more you could do! For example, to have more control of adjusting color during compositing, it’s very easy to render some matte passes for the cloth effect. For each of the three textures we set up (front, back, rim), simply replace one of them with a red emission shader, one with green, and one with blue. When you render that and bring that fileset into compositing, you can use a SeparateRGB node to pull each color as an alpha channel to color correct the render very easily.
You could also take it a bit further by saving another version of the project and making all three shaders diffuse white. Throw a light in the scene so you get some dramatic shadows from the tearing, then render out that pass. In compositing, use a Mix node set to multiply over the main render of the tearing effect, and now you’ve got a nice shadow added in to accentuate the depth. (You may have to rotoscope out the shadows on the visible tears.)
Also, as a side note, a few months ago when I was exploring ideas on how to do tearing cloth, Jesus stepped up and showed that ClothFX was also capable of doing it. Check out this demo video!