Building Demolition

This building demolition project is another personal project that I am working on during my time as the Education and Training intern at SideFX.

Here’s the building demolition reference that I was going for:

When I was originally creating this project, I wanted to add windows, and other additional things to make the building look more interesting. However, I quickly realized that I didn’t have the computer power and time to simulate since it was close to the end of my internship.

Therefore, my solution to minimize my iteration time was to only do the building and shatter two floors and alternating them while copying more floors.


Although the RBD material fracture node is very cool, it often messes up the geometry when I enable edge details. That’s why I decided to go with the copy and alternate solution. For each copy, I have to rotate and change their name attribute according to which floor it is.

There are a total of three different constraints.

  1. Red: Big Fracture
  2. Green: Small Fracture
  3. White: Constraint between each floor

I added noises to the strength of different levels of the constraint to make it breaks more interesting. I also grouped the areas in the middle where they are close to the explosions to make them break apart when the explosion happens.

In the DOPnet, I also added four custom wrangles to make them break in the way I wanted to.

This Geometry Wrangle turns the constraints at the explosion areas from Glue to Soft constraints when the explosion happens.

This Geometry Wrangle will release the left side of the building at a certain frame in order to make the building fall apart into two.

This Geometry Wrangle reduces the strength of the constraints over time to let the building slowly collapse.

This Geometry Wrangle adds velocity to pieces close to the explosion.


For the explosions, I did two pyro sims, one for the explosion itself and the second one is dust kickup from the explosions.

The sources are both based on a similar VEX code that I use in the DOPnet.