Using Bing Chat to answer your first question
Iray is a GPU accelerated path-traced renderer developed by Nvidia. It is possible to create images with a great accuracy of lighting in the scene and in high-definition (large resolution).
The IRay plug-in for IClone allows you to render from IClone.
Omniverse Create (soon to be called Composer) is NVidia's 3D creation software, and Omniverse Create also has a render option of IRay.
Yes, IRay takes a long time, and is it can make multiple passes per every frame. In Omniverse when I use IRay I set it to this:
I have found with Omniverse you should create a camera, not the perspective camera to use IRay (it tends to work better).
Here is a comparison of the same item rendered with 3 different renders in Omniverse:
Depending on the scene, Path Traced or even Real Time sometimes look better. IRay is better at glass and light translucent scenes, usually.
This forum is behaving weird with text.