Path Tracer - Model loading Libraries? so I am in the process of making my own GPU path tracer based on OpenCL as part of my bachelor thesis. I have already made a CPU and a GPU ray tracer based on OpenGL compute shaders but all I have ray-traced are simple spheres and planes.

1) Onto the main question, what do I need to path trace actual models like the teapot/dragon etc. Are there any standard, well known libraries for this purpose? Or do I have to write my own model loader? 

Writing my own loader seems all nice but I won't just have to read the data but maintain a proper data structure for all the triangles (K-d tree or octree perhaps) as well and then pass that structured data onto the GPU. If there is a library that can give me the data structure it'd be nice as I'll have to write the code for traversing it on the GPU only as I have already written one to traverse octrees for my GPU raytracer.
AssImp library may be a good choice for you, assuming you are using C++ ?. It supports a decent number of model formats.