Finally, now that you have a GeomVertexData and one or more
GeomPrimitive objects, you can create a Geom object and a GeomNode to
put the new geometry in the scene graph, so that it will be rendered.
geom = Geom(vdata)
node = GeomNode('gnode')
nodePath = render.attachNewNode(node)
The Geom constructor requires a pointer to the GeomVertexData object
you will be using. There is only one GeomVertexData associated with
any particular Geom. You can reset the Geom to use a different
GeomVertexData later, if you like, by calling geom.setVertexData().
The GeomNode constructor requires a name, which is the name of the
node and will be visible in the scene graph. It can be any name you
like that means something to you.
In the above example, we have created only one Geom, and added only
one GeomPrimitive to the Geom. This is the most common case when you
are creating geometry at runtime, although in fact a GeomNode may
include multiple Geoms, and each Geom may include multiple
GeomPrimitives. (However, all of the primitives added to a Geom must
have the same fundamental primitive type: triangles, lines, or points.
You can add GeomTriangles and GeomTristrips to the same Geom, or you
can add GeomLines and GeomLinestrips, but if you have GeomTriangles
and GeomLinestrips, you must use two different Geoms.)
It is important that the range of vertex index numbers used by your
GeomPrimitives is consistent with the number of vertices in your
GeomVertexData (for instance, if you have 100 vertices in your
GeomVertexData, your GeomPrimitives must only reference vertices
numbered 0 through 99). If this is not the case, you will get an
exception when you call addPrimitive().