Let me list my specs before I continue.
i7 4770k
18GB ram
980ti
Ok So my problem is as follows, I have a scene with a few hills of grass all made from Maya paintFX, The scene was originally rendered in Vray, so I took it and converted all my vray shaders to octane shaders, but before I did this I created a duplicate of my current render layer and created a layer override material and I chose a standard octane diffuse shader and added an octane sun sky system and clicked IPR and it fell on its arse and would not render anything. So I tried creating new render layers and doing one patch of grass at a time, a small patch of grass no problem, so I start adding and adding and it doesn't take much before it falls on its arse and I am watching the poly count and its no where near being reached.
I found this very interesting so I started another Maya instance and created a simple plane with a Maya pfx, I tried rendering the pfx before converting it to geometry as I would usually do and found that octane was able to render a paint FX.....This got me thinking.
So I went back to my original scene and deleted all my paint FX strokes essentially killing all my grass but leaving a static non animated version of the grass geometry behind and bam octane was able to render the scene? So this tells me that octane is counting the Maya PFX strokes as geometry and I'm clearly reaching my poly count limit, now what I find very interesting is that the paint FX strokes are not in my current render layer so WHY is octane counting the paint FX stroke as geometry??? to me this is not a limitation it is a bug of some sort or bad integration, Octane seems to be ignoring the fact that the PFX stroke isn't in the current render layer?? (Now I know your thinking "Contradiction as I mentioned earlier that before I deleted pfx strokes I created a new render layer and added small patches of grass and it rendered.....Yea this beats me too?
)Now the interesting thing is that I have the Redshift demo installed too as I am busy testing both these renderer's for a possible future job, Redshift renders this scene in seconds! the start up time to load it into the GPU is about 6 times faster, I sit and wait a very long time for octane to start rendering that scene and thats once I have deleted the PFX history, Redshift doesn't care about the PFX strokes and just loads it up in a few seconds and I have a live IPR and I can start playing.
Now onto my next question Once I have deleted all my PFX strokes and can finally render the scene with a default diffuse shader added to the geometry, I went ahead and took a bunch of grass geometry and a few other things like mushrooms and dew drops and zoomed in and started tinkering with my grass shader, I created a specular shader with a sss node and some displacement and roughness and got a really nice looking grass blade with some beautiful lighting and created this:
Now I took this grass shader and applied it to all the grass in the scene and I tried to render and bam, it gave me some crazy UV error
It actually had the cheek to complain to me about a blade of grass that was created by converting a PFX stroke to Geometry I found this to be quite hilarious as I'm sure you could imagine ("what has a UV got to do with getting a render out lol it should just look messed up not fall on its arse and just refuse to render"), so I created a new render layer and started adding each patch of grass till I found the culprit and found that it was several of them, I checked the UV's and they were perfect as any paint effect grass stroke would be at this point I was pulling hair out as it was now late into Sunday night or rather Monday morning and I still wasn't able to render a blasted frame! 
What bugs me about this is that if I put a diffuse shader on my grass it renders find, if I put the grass map into the diffuse colour and render its all good, if I start getting all technical and create a nice shader it freaks out, yet it renders fine on a small scene????
Please could someone help me out here and tell me what limitation I seem to be hitting or bug I have found or whats going on because Vray, arnold, and Redshift all render this scene no problems, no matter what I throw at it?
