|
|
@@ -91,14 +91,31 @@ The :ref:`CSGPolygon3D <class_CSGPolygon3D>` node extrude along a Polygon drawn
|
|
|
Custom meshes
|
|
|
~~~~~~~~~~~~~
|
|
|
|
|
|
-Any mesh can be used for :ref:`CSGMesh3D <class_CSGMesh3D>`; the mesh can be
|
|
|
-modeled in other software and imported into Godot. Multiple materials are
|
|
|
-supported. There are some restrictions for geometry:
|
|
|
-
|
|
|
-- it must be closed,
|
|
|
-- it must not self-intersect,
|
|
|
-- it must not contain internal faces,
|
|
|
-- every edge must connect to only two other faces.
|
|
|
+Custom meshes can be used for :ref:`CSGMesh3D <class_CSGMesh3D>` as long as the
|
|
|
+mesh is *manifold*. The mesh can be modeled in other software and imported into
|
|
|
+Godot. Multiple materials are supported.
|
|
|
+
|
|
|
+For a mesh to be used as a CSG mesh, it is required to:
|
|
|
+
|
|
|
+- be closed
|
|
|
+- have each edge connect to only two faces
|
|
|
+- have volume
|
|
|
+
|
|
|
+And it is recommended to avoid:
|
|
|
+
|
|
|
+- negative volume
|
|
|
+- self-intersection
|
|
|
+- interior faces
|
|
|
+
|
|
|
+Godot uses the `manifold <https://github.com/elalish/manifold>`__ library to
|
|
|
+implement CSG meshes. The technical definition of "manifold" used by Godot is
|
|
|
+the following, adapted from that library's `definition of "manifold"
|
|
|
+<https://github.com/elalish/manifold/wiki/Manifold-Library#manifoldness-definition>`__:
|
|
|
+
|
|
|
+ Every edge of every triangle must contain the same two vertices (by index) as
|
|
|
+ exactly one other triangle edge, and the start and end vertices must switch
|
|
|
+ places between these two edges. The triangle vertices must appear in clockwise
|
|
|
+ order when viewed from the outside of the Godot Engine manifold mesh.
|
|
|
|
|
|
.. image:: img/csg_custom_mesh.png
|
|
|
|
tetrapod