Godot plugin for in-editor box modeling

godot-ply

Godot plugin for in-editor box modeling.

Only tested in Godot 3.3.3. Icons are only good for dark mode.

See demos on youtube.

Installation

• Copy the contents of this repository into your addons folder for your godot project.
• Activate the plugin in your project settings.

Usage

Create a PlyInstance node in your scene, and select it.

Editing Meshes

There are four selection modes:

• 1 Mesh
• 2 Face
• 3 Edge
• 4 Vertex

There are two editor modes are toggled by the ` Transform toggle in the menu.

• Selection mode: select faces, edges, and vertices with the mouse
• Transform mode: use the gizmo to translate, rotate and scale

There are tools for each selection mode:

• Mesh
  • Generators
    • Plane: Generate a two-sided unit plane
    • Cube: Generate a unit cube
• Face
  • Loop: a quad loop in one direction
  • Loop: a quad loop in the other direction
  • ctrl-e Extrude: Extrudes the selected face(s) along their mean normal by 1 unit
• Edge
  • Loop: Select an edge loop from the given edge
  • ctrl-r Cut Loop: Add a loop cut perpindicular to the selected edge
  • Subdivide: Splits the selected edge into two parallel edges
  • Collapse: Collapses an edge into a single vertex at its midpoint
• Vertex
  • None, yet!

Collisions

Collision meshes are updated automatically if there is a CollisionShape child of the PlyInstance at $StaticBody/CollsionShape. This is the default naming if you use the Create Trimesh Static Body tool.

Details

Meshes are meant to only be oriented manifolds. Some properties:

• Each edge has one or two faces (although we generally use exactly 2)
• All of an edge's faces have compatible orientation -- that is the edge origin and destination are in opposite order for opposite faces.

Ply uses a winged edge representation for edges, but omit counterclockwise navigation:

omitted
left ccw        right cw
         \     /
          \   /
           \ /
            o destination
            ^
            |
left face   |   right face
            |
            o origin
           / \
          /   \
         /     \
left cw          right ccw
                 omitted

Implications

Given this representation, a few limitations occur that are representable in other tools:

• One cannot abritrarily extrude edges into one-sided faces, or one edge would be incident with >2 faces.
• One cannot flip individual faces, as the faces would no longer have compatible orientation.

Contributing

Feel free to contribute! Both issues and pull requests are very welcome.

Feel free to contact me on the godot discord server, where my name is hints