jasonwebb / unity-space-colonization

Unity implementation of the space colonization algorithm to generate organic branching structures.

Requirements

• TubeRenderer ($10) by Sixth Sensor

Interface guide

Algorithm parameters

1. Attraction distance - branches that are within this distance (and outside the kill distance) of an attractor will grow towards that attractor.
2. Kill distance - how close branches can grow to attraction nodes before stopping.
3. Segment length - length of each branch segment of the generated structure. In each iteration of the simulation, one segment is added to the tips of each branch that is not within a kill distance of an attractor.

Branch rendering

1. Material - reference to a material object that is applied to each individual branch segment.
2. Enable vein thickening - progressively increase the radius of each branch segment starting from the tip (smallest) to the root node (largest).
   • If enabled ...
     • Minimum radius - smallest thickness that a branch can get.
     • Maximum radius - largest thickness that a branch can get.
     • Radius increment - rate at which the radius changes across each branch segment from tip to root.
   • If disabled ...
     • Radius - constant radius for all branch segments.

Attractor generation

1. Attractor placement - dropdown with the following options:
   • SPHERE
     • Radius - radius of sphere.
     • Attractor count - number of attractors to scatter.
   • GRID - evenly spaced attractors on a grid.
     • Dimensions - length, width, height of grid.
     • Resolution - number of attractors per axis.
     • Jitter - amount of random displacement per attractor to make them less uniform.
   • MESH - scatter attractors on the surface or inside of a custom mesh.
     • Target mesh - reference to the mesh you want to use.
     • Raycasting attempts - number of times to try casting a random ray. Unity's collision detection is not perfect, so the actual number of attractors that are generated will be much less than this number.
     • Raycasting direction - direction to fire random rays for attractor placement.
       • INWARDS - casts random rays from outside the mesh towards the origin. Scatters points on the surface.
       • OUTWARDS - casts random rays from the origin to the outside. Scatters points on inner surface.
       • DOME - casts random rays in a hemisphere around the mesh.
2. Attractor gizmo radius - size of the editor gizmos that indicate the position of each attractor.
3. Actions
   • Generate attractors - attempt to place attractors using the parameters chosen above. This may take a while depending on the parameters chosen and the complexity of the mesh.
   • Clear - remove all attractors from the scene, like a reset.

Root node(s)

1. Type of root node(s) - dropdown with the following options:
   • INPUT
     • Root node object - reference to the point object you want to use as a root node.
   • MESH
     • Target mesh - reference to the mesh you want to randomly place root nodes on.
     • Number of root nodes - how many randomly-placed root nodes you want.

Bounds

1. Use bounds - enable or disable restriction of branch growth to a chosen bounding volume.
   • If enabled ...
     • Bounding mesh - reference to a mesh object you want to use to constrain growth inside of.

Obstacles

1. Use obstacles - enable or disabled the use of obstacle objects that branch growth cannot occur in.
   • If enabled ...
     • Size - how many obstacles you want to use.
     • Element [n] - reference to a mesh object that the branch growth must avoid.

Run controls

1. Iterations to run - number of times to run the simulation. Start small until you know what you're doing!
2. Run - press to run the simulation for the number of times chosen above.
3. Reset - press to remove any previously-generated branches so growth can start over.

Export

1. Filename - name of the file you want to export. Be sure to provide a file extension.
2. Export - press to export the generated branches on the screen to a file with the name provided above.