Setting up mycelium node network
To start the simulation I needed a surface for the mycelium to path along. I created a 1:1 holdout of the door based on the 3D tracked pointcloud from 3D Equalizer. I then scaled this down and rotated it to be at the best for the sim, this will then be later undone to get back to the original scale. The mycelium works by scattering a point onto the mesh, then manually moving that point to the desired start location, this is done 2 times in my animation. Then the points have some attributes initialized and fed into some vex code. This code essentially sets a goal for the points to path to then creates a curve towards it, this curve sticks to the surface of the holdout mesh. I can then further edit the curve with variables such as, distance from the mesh, length, segment length, and the directionality of the path (if it goes in a straight line to the goal or takes a long winding route).
The curves are then given attributes based on the desired frame range that control the animation. using these attribues I can spawn sub paths from the initial curve when the desired value reaches a certain point, allowing for the sub mycelium to only start growing only when the main path has reached that point.
To get these curves into a mesh I used polywire and smoothing to reach the desired look. This simulation was then put into a file cache to allow for easy viewing and avoid have to constantly calculate the sim whenever I wanted to view it.
Once I had the final sim I could move the mesh from the SOP (building) workspace to the Solaris USD (rendering) workspace.