left : iClone render                                                           Right : Iray Render

Quality compressor Video : 8                                          Default parameters
Quality compressor Audio : 8                                          Frame Rate : 60
Frame Rate : 60                                                              Frame size  : HD 1080p (1920x1080)
Frame size  : HD 1080p (1920x1080)                            Total Frames : 900
Render quality : High (3x3)                                             Frame itération : 200
High quality shadow                                                        Render time : 4 hours
Total number of frames : 900
Render time : 12 mn

1 - The colors are more intense rendered by iclone, but maybe if I had taken a longer iteration time in IRay I would have had a better result;

2 - The yellow colour of the skirt is different between the 2 renderings;

3 - The ground (water) and the reflection do not appear in the IRay rendering. (but this may be due to my lack of knowledge of IRay settings).
4 - it seems to me that physics does not give the same result in IRay

For my part, I find that the native rendering by iclone suits me perfectly, I might use IRay for very short sequences when I master it better.

I actually prefer the iClone version.

But that was one u--y lady!

Both renders ran very smoothly.
Did you convert the materials to IRay before rendering in IRay?

Nathan

The character is cc3 type and all textures are traditional shader type.
I made no conversion to IRay material.

Iray does not render iClone water. However, you can use a reflective ground plane instead.

Did you bake the cloth physics? That would be necessary to get the same result.

---

I realized that the water wasn't there at the end of the rendering. After 4 hours, but I didn't want to do it again. But indeed in this case it would have been a good solution to use a reflective ground plane instead.
I found nowhere in the settings of Iray how to bake cloth physics.

You have to bake physics in iClone. Regular way. Enable Bake Animation in *Project", play in By Frame mode, disable Bake Animation and disable physics for hair and skirt.
On a side note, it is strongly advised to convert Traditional materials to PBR for Iray.

And a reminder: Render with 1280x720 (it would be twice as fast) and then upscale image sequence to 1920x1080 with Topaz Gigapixel AI.
Results might vary, but it does darn good job in most of the cases.

Finally, don't forget about Tonemapper, Tweak settings on single frame preview and all settings would be transparent for animation.

Thank you for all this excellent advice. I will take it into account and implement it as soon as possible.