what is mesh instancing

Programming guide suggests flattened geometry over deep trees with transform node and “Also, if possible,
combine multiple meshes into a single mesh”.

What does the mesh mean?
Array of geometries?

Thanks!

In some sense, yeah, it’s an array of geometries. Polygon meshes are often used when defining a model and usually include a list of vertices, normals, etc… The wikipedia page explains it pretty well.

So if you have several models/meshes, OptiX will benefit from them being combined into the same mesh (especially if they are static!)