Houdini 20.0 Shelf tools

Simple Bonfire shelf tool

Creates a bonfire simulation using the sparse pyro solver.

On this page
Pyro and ember simulation in the viewport. Colorspace: ACES, Voxels Size: 0.0085.
Pyro and ember simulation rendered with Karma. Colorspace: ACES, Voxels Size: 0.0085.


This shelf tool sets up a sparse pyro simulation of a bonfire with addition embers. Source and simulation settings used by this tool are identical to the Bonfire tool on the Sparse Pyro FX tab. However, rather than building a DOP network, it uses the SOP-level tools to build a simple network to work with sparse pyro.

Understanding Simple Bonfire

  • If you have a Houdini FX License, you can dive inside the solver and edit the subnet with custom DOP forces. Otherwise, you can stay at the SOP level and use the exposed parameters on the node.

  • bonfire_base controls the shape of the fire’s base. You can switch out this node for another geometry object if you want to change the look of the base. For example, you could use geometry representing fire logs.

  • pyrosolver_bonfire performs the simulation. Parameters on this node have the greatest influence on the speed and height of the fire. Parameters on the Solving tab allow you to make the following modifications.

    To...Do this

    Increase the speed of the flames

    Boost the Buoyancy Scale.

    This will also increase the height of the fire.

    Change the motion of fire

    Adjust the Disturbance, Shredding, and Turbulence parameters on the Shape tab of the Sparse Pyro Solver.

    Disturbance generically breaks up the flames, shredding redirects the velocities (creating the licks), and Turbulence mimics a chaotic wind.

  • pyrolook sets the proper viewport visualization settings, as well as generates the Scatter volume for rendering. However this node does not assign any shader for rendering.

  • popnet_embers simulates particles that are used as embers flying out from the fire.

  • sparktrail takes the particle simulation of the embers and generates curves from the movement of those particles to render them as embers.

  • lopnet_bonfire_with_embers is a simple lopsetup created to demonstrate the shading of fire and embers.

Shelf tools

Using the shelf

  • Customize the shelf

    How to change the look of the shelf, change and rearrange its contents, and create your own shelf tools.