As I explore Houdini, I find myself continually in awe at the ease with which I can create complex and physically realistic effects. This post looks at creating geometry and applying a heat source to it to cause it to glow and melt.
The first experiment in the video above uses a simple tube, but the second experiment is a little bolder: here I use two toruses and four tubes to build what could be the frame to a bar stool or small table. More accurately the second experiment uses a single torus and a single tube along with a handful of transforms and a merge to build the geometry:
Which looks like this:
To turn the geometry into something meltable, I applied the Lava From Object shelf tool which turns it into a particle fluid. The two interesting things about the network created by this tool is that the fluid's viscosity and the particle color are both linked to its temperature.
By default, the fluid temperate is 0.5, but by changing this to 0.0 and upping its viscosity, it becomes pretty much a solid.
To get it melting, I added an additional box geometry and used the Heat Within Volume shelf tool to create a heating volume from it. Note that particles need to be within a heating volume to affect them - my initial attempt to convert a ground plane to a heat source failed because the particles were touching, but not within, the plane.
After these steps, the DOP Network looks like this:
Temperature diffusion within the melting object is controlled by the Gas Temperature Update node: in the second experiment, I upped the radius to 2.5 to increase the conductivity of the fluid.
A project that was super simple to implement but gives a pretty funky effect!