Thank you for your explanations, Dust Rider.
I didn't look at this thread any more on DAZ forum because I didn't understand well the Octane render's advantages compared to that of Carrara.
Now that I understood well thanks to you, I realize that it's especially interesting for still images because in animation, one uses sometimes hair, also for grass etc...and if we wants to keep a homogeneity in the sequences, it isn't possible in this case.
I have two questions all the same:
1-What about particles, clouds etc.?
2- Does we have obligatorily to use the plugin for Carrara or can we do the work directly in the standalone version ?
I post this here, because they are to much specialists in the DAZ forum and I'm afraid that my questions are too basic...
Thank you again.

PS: your render with the Stonemason towers is very impressive !

Here is a quote from Sighman (the plugin developer) about particles "The plugin only supports emitting Objects. All others types, including Metaballs, are not supported." But, metaballs that are not part of a particle system are supported/rendered by Octane. Carrara clouds are not supported at this point, but Octane does have a volumetric system capable of making "clouds" (in enclosed geometry/volumes). Here is an image with clouds done by one of the people at Otoy (but I don't know how he did it) http://render.otoy.com/newsblog/wp-content/uploads/2013/03/CloudForest121.jpg The attached image is one I did just as a quick test with a Carrara cloud model available at sharecg (http://www.sharecg.com/v/41244/browse/5/3D-Model/Cumulonimbus-cloud). Here is another render I did learning how to set up volumetrics in Octane for lighting effects (Specular material type with SSS): http://www.daz3d.com/gallery/#images/42774

Octane has a great procedural texture system, though I think it may be missing a few things that are available in Carrara (I haven't really done any sort of true comparison). Conversion of Carrara procedural shaders is not supported at this point.

Carrara animations work well via the plugin  (other than Dynamic hair of course, but Octane does have a hair system), and Octane now has motion blur for animation as well. This demo reel has quite a few examples of animations done by Orion_uk: https://www.youtube.com/watch?v=5GeGGs_QU-I

You can fine the release demo reel that covers a lot of the features here: https://www.youtube.com/watch?v=5GeGGs_QU-I

Unfortunately neither of these demo reels really show the highly interactive nature of the plugin (i.e. near real time feed back when editing materials, lights, object placement, etc.) which for me is a huge plus!!

You have the option of doing all of your work in Carrara and the plugin, or you can use the plugin to export your project to the Octane standalone native formats (.ocs or .orbx) with all of your materials, etc. intact. You can also export from Carrara to .obj and import that into Octane standalone, but it is A LOT more work than exporting from the plugin to native Octane formats.

Your questions definitely aren't too basic, and are about things that I'm sure a lot of people have questions about. Hope all this helps - and makes sense. It's really hard to proof read the new posts with the changes to the forum. Feel free to ask any other questions you might have.

Oh ... thanks for the compliment on the Stonemason image. I did it when we started working/testing with the Octane 2.0 version of the plugin. With 2.0 the limitations on the number of textures slots available went away, so I went crazy for a few days just testing things that pushed (or went beyond) the texture limits with Octane 1.5. All of the materials were edited to make them look better, and I used a Carrara Ocean primitive for the water. As I recall, the render took between 10-15 min. (after all the shader work which was probably about a half hour). About a week later I picked up Fenric's Shader Doctor plugin for Carrara - a must have when using Stonemason scenes!! 

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