Tearing the Fabric of Reality
This is an effect that I wanted to make before I even began to learn Houdini (more than seven years ago!) and am now happy to say that I was able to do it justice. I saw an artist on Twitter named Late as Usual doing something similar in Blender, and realized that the abstract idea I’d had floating in my head all those years could actually be realized in a few concrete steps.
The pieces are fractured and exploded outward using a fully procedural setup created with MOPs. Then a shader shifts the surrounding environment around accordingly and projects it back on to the shattered pieces. All pieces within a certain radius of the portal’s center are outlined with a bright color to add visual clarity. Finally, the portal's interior is created by using another shader illusion with a panoramic image that can be swapped out, so the destination can be anywhere imagineable.
Other Applications
This setup can be repurposed to fit a wide array of scenarios. Here I’ve applied the effect to the geometry of a cloth simulation in an even more literal take on “fabric of reality.”
The possibilities are essentially limitless, so long as the geometry has a planar rest state. The portal could take the form of bricks breaking, glass shattering, or anything else you can simulate with polygons. Even the exterior shader on its own could be adapted to create an invisibility cloak or futuristic camouflage effect.