How to convert files from Rhino3D
to Collada?

Rhinoceros (typically abbreviated Rhino, or Rhino3D) is a commercial 3D computer graphics and computer-aided design (CAD) application software developed by Robert McNeel & Associates. It is used in industries including architecture, industrial and product design, in multimedia and graphic design and runs on Microsoft Windows and OS X. Rhino uses Grasshopper, a visual scripting language add-on, developed by Robert McNeel & Associates.

Rhino is based on the NURBS mathematical model, so it focuses on producing precise representations of curves and freedom surfaces. It allows users to create, edit, analyse, and visualize NURBS curves, surfaces, solid bodies, point clouds and polymeshes.

Collada (COLLAborative Design Activity) is an interchange format for interactive 3D applications. Originally developed by Sony Computer Industry, now it is managed by the Khronos Group, a member-funded industry consortium, which now shares the copyright with Sony, Recently Collada has been well adopted by ISO as a publicly available specification, ISO/PAS 17506.

It is an XML-based schema that allows data exchange among 3D Digital Content Creation tools, such as SketchUp, Maya, 3ds Max, and Rhino. COLLADA files have the *.dae file extension, which stands for digital asset exchange.