Generators

Python has support for generators using the yield keyword.

Tree functions can be written as generators. Each yielded value becomes a separate output, just like returning a tuple:

@tree("Primitive Shapes")
def primitive_shapes():
    yield cube().mesh        # Result
    yield uv_sphere().mesh   # Result 2
    yield 5                  # Result 3

This is handy when the outputs are computed in several steps, since each one can be yielded as soon as it’s ready.

Joining Geometry

Yielded geometry is not joined automatically. To output several geometries as one, pass a list to Join Geometry:

@tree("Primitive Shapes")
def primitive_shapes():
    return join_geometry(geometry=[
        cube().mesh,
        uv_sphere().mesh,
        cylinder().mesh,
    ]).geometry

Multi-input sockets, such as the Geometry input of Join Geometry or the Mesh input of Mesh Boolean, accept a list of sockets.

The first output is always displayed when using a Geometry Nodes modifier. Ensure it is a Geometry socket, unless you are using the function as a node group.