I was outputting from Iclone8 to a usd file and rendering with nvidia omniverse create.I purchased the IRay plugin today.What is the difference between IRay and omnivores crete?I know they are both nvidia services.IRay seems to take more time to render.

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.

Creator of the free website:
PixelDatabase.Net
A Free Online Text Based Image Editor

Iray is an older Nvidia ray tracing rendering system that is gradually being replaced by Omniverse. For iClone users the Iray Plug-in can be used without requiring Omniverse be installed. In addition the Iray Plug-in can also be used by older GTX Nvidia graphics cards whereas Omniverse requires an RTX Nvidia graphic card.


                                                                

Peter
Forum Administrator

www.reallusion.com

Omniverse is not a rendering technology per-se.  Instead is is a framework (software tools and development kits) for many different types of 3D/AI/Simulation workflows and presentations.... including rendering.
At this time, Omniverse directly supports several rendering engines including Iray.
See:  https://docs.omniverse.nvidia.com/prod_materials-and-rendering/prod_materials-and-rendering/manual.html
And: https://www.youtube.com/watch?v=dCvq2ZyYmu4