Tools for creating RBD and PryoFX simulations are now available at the SOP level in Houdini. This creates a perfect environment for preparing and directing the look of your simulations. Learn how to take a house model that has been prepped for destruction, start by fracturing the parts then build up constraint networks to hold the pieces together. Learn about all the nodes needed to set up and run both an RBD and PyroFX simulations. There are some places where you can choose to dive into DOPS to refine the results. You will also learn how to render these effects using both Mantra and Solaris/Karma.
Note: With most of this lesson taking place at the SOP level, many of these techniques can be used in Houdini CORE. To dive into DOPS to add secondary effects, Houdini FX would be needed.
The project files for this lesson include the house geometry. If you would like to build the model yourself, you can follow the procedural house tutorial which teaches how to properly organize a model for future destruction.
Take a quick look at the final destruction shot and learn what techniques were used to set it up.
1 | Fracture the Geometry
Start by taking the different parts of the house model and applying material-based destruction. This provides unique fracturing for stone, wood and glass. Next, setup Custom constraint networks for all the places where different materials connect to each other.
2 | RBD Simulation
The RBD Bullet solver will be added in SOPs to run the simulation. To create the explosion, a blob will be added with velocity vectors that can be transferred to the fractured pieces to drive them out. You will then tinker with the constraint networks to get just the right look for the simulation.
3 | Pyro FX | Burst Source & Solver
The new Pyro FX workflow using the burst source and the PryoFX solver in SOPS are used to create the fire and smoke. Learn how to set up the interactive "minimal" solve and then how to refine the simulation to get the right look. The burst source is also used to transfer velocity to the house to get a better integration between the house explosion and the Pyro FX.
4 | Mantra Render | Shaders & ACES
Set up the shot using materials, lights, a camera and render settings. This rendering will be accomplished using the Mantra renderer which works at the object level of Houdini. Groups on the different parts of the house will be used to assign materials and time will be taken to get the look of the Pyro Shader just right.
5 | Add Soft Constraints in DOPS
Refine the look of the RBD sim by setting up soft constraints and diving into DOPS for added control. Create a more elastic look as the house explodes by loosening up the constraints.
6 | Tweak Microsolvers in DOPS
In the DOP network found inside the Pyro FX solver, you can add microsolvers to tweak the way in which the noise is handled using gas disturb and gas blur. Learn how it is possible to further direct the look of your simulation once you start working at this lower level.
7 | Solaris | Karma Render
Export the house destruction and the PyroFX explosion using USD then reimport into Houdini's Solaris context where you can render with Karma. Learn how to pull cameras and materials from your Mantra rendering and reuse them in Solaris.