Add optixHello example

[keckj]

Hello,

thanks for your amazing work, your wrapper works flawlessly on my machine (at least for the two provided examples by using cuda 11.4, optix 7.3 on ubuntu 20.04).

Here is the implementation of the OptixHello example, it is not much, but I needed to start somewhere.

Do you have any plan to support interactive examples ? We could use a high-level python opengl-based API coupled with OpenGL/CUDA buffer interop. Apparently CUDA/OpenGL interop is not yet available in cupy. Of course, we could map the cupy buffer by using directly the raw pointer, but last time I checked, the cuda python low-level bindings did not wrap all the required interop functions.

[mortacious]

Hey, thanks for your contribution!
Nice to hear, that everything worked for you out of the box.

I'm planning to re-implement all the examples from the SDK in python in the mid term so this is definitely helpful :).

Currently I do not plan to develop this package beyond the actual OptiX functionality, so a Bridge to OpenGL is outside the scope and would be more fitting within the cupy-library anyways ;).

However, you could easily develop such a bridge by wrapping the functions from the CUDA runtime API in cython. Cupy's ndarray is basically a wrapper around a CUdeviceptr and can therefore easily be used with the low-level functions.